(function(f){if(typeof exports===“object”&&typeof module!==“undefined”){module.exports=f()}else if(typeof define===“function”&&define.amd){define([],f)}else{var g;if(typeof window!==“undefined”){g=window}else if(typeof global!==“undefined”){g=global}else if(typeof self!==“undefined”){g=self}else{g=this}g.chai = f()}})(function(){var define,module,exports;return (function(){function r(e,n,t){function o(i,f){if(!n){if(!e){var c=“function”==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error(“Cannot find module '”i“'”);throw a.code=“MODULE_NOT_FOUND”,a}var p=n={exports:{}};e[0].call(p.exports,function®{var n=e[1];return o(n||r)},p,p.exports,r,e,n,t)}return n.exports}for(var u=“function”==typeof require&&require,i=0;i);return o}return r})()({1:[function(require,module,exports){ module.exports = require('./lib/chai');

},{“./lib/chai”:2}],2:[function(require,module,exports){ /*!

* chai
* Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

var used = [];

/*!

* Chai version
*/

exports.version = '4.2.0';

/*!

* Assertion Error
*/

exports.AssertionError = require('assertion-error');

/*!

* Utils for plugins (not exported)
*/

var util = require('./chai/utils');

/**

* # .use(function)
*
* Provides a way to extend the internals of Chai.
*
* @param {Function}
* @returns {this} for chaining
* @api public
*/

exports.use = function (fn) {

if (!~used.indexOf(fn)) {
  fn(exports, util);
  used.push(fn);
}

return exports;

};

/*!

* Utility Functions
*/

exports.util = util;

/*!

* Configuration
*/

var config = require('./chai/config'); exports.config = config;

/*!

* Primary `Assertion` prototype
*/

var assertion = require('./chai/assertion'); exports.use(assertion);

/*!

* Core Assertions
*/

var core = require('./chai/core/assertions'); exports.use(core);

/*!

* Expect interface
*/

var expect = require('./chai/interface/expect'); exports.use(expect);

/*!

* Should interface
*/

var should = require('./chai/interface/should'); exports.use(should);

/*!

* Assert interface
*/

var assert = require('./chai/interface/assert'); exports.use(assert);

},{“./chai/assertion”:3,“./chai/config”:4,“./chai/core/assertions”:5,“./chai/interface/assert”:6,“./chai/interface/expect”:7,“./chai/interface/should”:8,“./chai/utils”:22,“assertion-error”:33}],3:[function(require,module,exports){ /*!

* chai
* http://chaijs.com
* Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

var config = require('./config');

module.exports = function (_chai, util) {

/*!
 * Module dependencies.
 */

var AssertionError = _chai.AssertionError
  , flag = util.flag;

/*!
 * Module export.
 */

_chai.Assertion = Assertion;

/*!
 * Assertion Constructor
 *
 * Creates object for chaining.
 *
 * `Assertion` objects contain metadata in the form of flags. Three flags can
 * be assigned during instantiation by passing arguments to this constructor:
 *
 * - `object`: This flag contains the target of the assertion. For example, in
 *   the assertion `expect(numKittens).to.equal(7);`, the `object` flag will
 *   contain `numKittens` so that the `equal` assertion can reference it when
 *   needed.
 *
 * - `message`: This flag contains an optional custom error message to be
 *   prepended to the error message that's generated by the assertion when it
 *   fails.
 *
 * - `ssfi`: This flag stands for "start stack function indicator". It
 *   contains a function reference that serves as the starting point for
 *   removing frames from the stack trace of the error that's created by the
 *   assertion when it fails. The goal is to provide a cleaner stack trace to
 *   end users by removing Chai's internal functions. Note that it only works
 *   in environments that support `Error.captureStackTrace`, and only when
 *   `Chai.config.includeStack` hasn't been set to `false`.
 *
 * - `lockSsfi`: This flag controls whether or not the given `ssfi` flag
 *   should retain its current value, even as assertions are chained off of
 *   this object. This is usually set to `true` when creating a new assertion
 *   from within another assertion. It's also temporarily set to `true` before
 *   an overwritten assertion gets called by the overwriting assertion.
 *
 * @param {Mixed} obj target of the assertion
 * @param {String} msg (optional) custom error message
 * @param {Function} ssfi (optional) starting point for removing stack frames
 * @param {Boolean} lockSsfi (optional) whether or not the ssfi flag is locked
 * @api private
 */

function Assertion (obj, msg, ssfi, lockSsfi) {
  flag(this, 'ssfi', ssfi || Assertion);
  flag(this, 'lockSsfi', lockSsfi);
  flag(this, 'object', obj);
  flag(this, 'message', msg);

  return util.proxify(this);
}

Object.defineProperty(Assertion, 'includeStack', {
  get: function() {
    console.warn('Assertion.includeStack is deprecated, use chai.config.includeStack instead.');
    return config.includeStack;
  },
  set: function(value) {
    console.warn('Assertion.includeStack is deprecated, use chai.config.includeStack instead.');
    config.includeStack = value;
  }
});

Object.defineProperty(Assertion, 'showDiff', {
  get: function() {
    console.warn('Assertion.showDiff is deprecated, use chai.config.showDiff instead.');
    return config.showDiff;
  },
  set: function(value) {
    console.warn('Assertion.showDiff is deprecated, use chai.config.showDiff instead.');
    config.showDiff = value;
  }
});

Assertion.addProperty = function (name, fn) {
  util.addProperty(this.prototype, name, fn);
};

Assertion.addMethod = function (name, fn) {
  util.addMethod(this.prototype, name, fn);
};

Assertion.addChainableMethod = function (name, fn, chainingBehavior) {
  util.addChainableMethod(this.prototype, name, fn, chainingBehavior);
};

Assertion.overwriteProperty = function (name, fn) {
  util.overwriteProperty(this.prototype, name, fn);
};

Assertion.overwriteMethod = function (name, fn) {
  util.overwriteMethod(this.prototype, name, fn);
};

Assertion.overwriteChainableMethod = function (name, fn, chainingBehavior) {
  util.overwriteChainableMethod(this.prototype, name, fn, chainingBehavior);
};

/**
 * ### .assert(expression, message, negateMessage, expected, actual, showDiff)
 *
 * Executes an expression and check expectations. Throws AssertionError for reporting if test doesn't pass.
 *
 * @name assert
 * @param {Philosophical} expression to be tested
 * @param {String|Function} message or function that returns message to display if expression fails
 * @param {String|Function} negatedMessage or function that returns negatedMessage to display if negated expression fails
 * @param {Mixed} expected value (remember to check for negation)
 * @param {Mixed} actual (optional) will default to `this.obj`
 * @param {Boolean} showDiff (optional) when set to `true`, assert will display a diff in addition to the message if expression fails
 * @api private
 */

Assertion.prototype.assert = function (expr, msg, negateMsg, expected, _actual, showDiff) {
  var ok = util.test(this, arguments);
  if (false !== showDiff) showDiff = true;
  if (undefined === expected && undefined === _actual) showDiff = false;
  if (true !== config.showDiff) showDiff = false;

  if (!ok) {
    msg = util.getMessage(this, arguments);
    var actual = util.getActual(this, arguments);
    throw new AssertionError(msg, {
        actual: actual
      , expected: expected
      , showDiff: showDiff
    }, (config.includeStack) ? this.assert : flag(this, 'ssfi'));
  }
};

/*!
 * ### ._obj
 *
 * Quick reference to stored `actual` value for plugin developers.
 *
 * @api private
 */

Object.defineProperty(Assertion.prototype, '_obj',
  { get: function () {
      return flag(this, 'object');
    }
  , set: function (val) {
      flag(this, 'object', val);
    }
});

};

},{“./config”:4}],4:[function(require,module,exports){ module.exports = {

/**
 * ### config.includeStack
 *
 * User configurable property, influences whether stack trace
 * is included in Assertion error message. Default of false
 * suppresses stack trace in the error message.
 *
 *     chai.config.includeStack = true;  // enable stack on error
 *
 * @param {Boolean}
 * @api public
 */

includeStack: false,

/**
 * ### config.showDiff
 *
 * User configurable property, influences whether or not
 * the `showDiff` flag should be included in the thrown
 * AssertionErrors. `false` will always be `false`; `true`
 * will be true when the assertion has requested a diff
 * be shown.
 *
 * @param {Boolean}
 * @api public
 */

showDiff: true,

/**
 * ### config.truncateThreshold
 *
 * User configurable property, sets length threshold for actual and
 * expected values in assertion errors. If this threshold is exceeded, for
 * example for large data structures, the value is replaced with something
 * like `[ Array(3) ]` or `{ Object (prop1, prop2) }`.
 *
 * Set it to zero if you want to disable truncating altogether.
 *
 * This is especially userful when doing assertions on arrays: having this
 * set to a reasonable large value makes the failure messages readily
 * inspectable.
 *
 *     chai.config.truncateThreshold = 0;  // disable truncating
 *
 * @param {Number}
 * @api public
 */

truncateThreshold: 40,

/**
 * ### config.useProxy
 *
 * User configurable property, defines if chai will use a Proxy to throw
 * an error when a non-existent property is read, which protects users
 * from typos when using property-based assertions.
 *
 * Set it to false if you want to disable this feature.
 *
 *     chai.config.useProxy = false;  // disable use of Proxy
 *
 * This feature is automatically disabled regardless of this config value
 * in environments that don't support proxies.
 *
 * @param {Boolean}
 * @api public
 */

useProxy: true,

/**
 * ### config.proxyExcludedKeys
 *
 * User configurable property, defines which properties should be ignored
 * instead of throwing an error if they do not exist on the assertion.
 * This is only applied if the environment Chai is running in supports proxies and
 * if the `useProxy` configuration setting is enabled.
 * By default, `then` and `inspect` will not throw an error if they do not exist on the
 * assertion object because the `.inspect` property is read by `util.inspect` (for example, when
 * using `console.log` on the assertion object) and `.then` is necessary for promise type-checking.
 *
 *     // By default these keys will not throw an error if they do not exist on the assertion object
 *     chai.config.proxyExcludedKeys = ['then', 'inspect'];
 *
 * @param {Array}
 * @api public
 */

proxyExcludedKeys: ['then', 'catch', 'inspect', 'toJSON']

};

},{}],5:[function(require,module,exports){ /*!

* chai
* http://chaijs.com
* Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

module.exports = function (chai, _) {

var Assertion = chai.Assertion
  , AssertionError = chai.AssertionError
  , flag = _.flag;

/**
 * ### Language Chains
 *
 * The following are provided as chainable getters to improve the readability
 * of your assertions.
 *
 * **Chains**
 *
 * - to
 * - be
 * - been
 * - is
 * - that
 * - which
 * - and
 * - has
 * - have
 * - with
 * - at
 * - of
 * - same
 * - but
 * - does
 * - still
 *
 * @name language chains
 * @namespace BDD
 * @api public
 */

[ 'to', 'be', 'been', 'is'
, 'and', 'has', 'have', 'with'
, 'that', 'which', 'at', 'of'
, 'same', 'but', 'does', 'still' ].forEach(function (chain) {
  Assertion.addProperty(chain);
});

/**
 * ### .not
 *
 * Negates all assertions that follow in the chain.
 *
 *     expect(function () {}).to.not.throw();
 *     expect({a: 1}).to.not.have.property('b');
 *     expect([1, 2]).to.be.an('array').that.does.not.include(3);
 *
 * Just because you can negate any assertion with `.not` doesn't mean you
 * should. With great power comes great responsibility. It's often best to
 * assert that the one expected output was produced, rather than asserting
 * that one of countless unexpected outputs wasn't produced. See individual
 * assertions for specific guidance.
 *
 *     expect(2).to.equal(2); // Recommended
 *     expect(2).to.not.equal(1); // Not recommended
 *
 * @name not
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('not', function () {
  flag(this, 'negate', true);
});

/**
 * ### .deep
 *
 * Causes all `.equal`, `.include`, `.members`, `.keys`, and `.property`
 * assertions that follow in the chain to use deep equality instead of strict
 * (`===`) equality. See the `deep-eql` project page for info on the deep
 * equality algorithm: https://github.com/chaijs/deep-eql.
 *
 *     // Target object deeply (but not strictly) equals `{a: 1}`
 *     expect({a: 1}).to.deep.equal({a: 1});
 *     expect({a: 1}).to.not.equal({a: 1});
 *
 *     // Target array deeply (but not strictly) includes `{a: 1}`
 *     expect([{a: 1}]).to.deep.include({a: 1});
 *     expect([{a: 1}]).to.not.include({a: 1});
 *
 *     // Target object deeply (but not strictly) includes `x: {a: 1}`
 *     expect({x: {a: 1}}).to.deep.include({x: {a: 1}});
 *     expect({x: {a: 1}}).to.not.include({x: {a: 1}});
 *
 *     // Target array deeply (but not strictly) has member `{a: 1}`
 *     expect([{a: 1}]).to.have.deep.members([{a: 1}]);
 *     expect([{a: 1}]).to.not.have.members([{a: 1}]);
 *
 *     // Target set deeply (but not strictly) has key `{a: 1}`
 *     expect(new Set([{a: 1}])).to.have.deep.keys([{a: 1}]);
 *     expect(new Set([{a: 1}])).to.not.have.keys([{a: 1}]);
 *
 *     // Target object deeply (but not strictly) has property `x: {a: 1}`
 *     expect({x: {a: 1}}).to.have.deep.property('x', {a: 1});
 *     expect({x: {a: 1}}).to.not.have.property('x', {a: 1});
 *
 * @name deep
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('deep', function () {
  flag(this, 'deep', true);
});

/**
 * ### .nested
 *
 * Enables dot- and bracket-notation in all `.property` and `.include`
 * assertions that follow in the chain.
 *
 *     expect({a: {b: ['x', 'y']}}).to.have.nested.property('a.b[1]');
 *     expect({a: {b: ['x', 'y']}}).to.nested.include({'a.b[1]': 'y'});
 *
 * If `.` or `[]` are part of an actual property name, they can be escaped by
 * adding two backslashes before them.
 *
 *     expect({'.a': {'[b]': 'x'}}).to.have.nested.property('\\.a.\\[b\\]');
 *     expect({'.a': {'[b]': 'x'}}).to.nested.include({'\\.a.\\[b\\]': 'x'});
 *
 * `.nested` cannot be combined with `.own`.
 *
 * @name nested
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('nested', function () {
  flag(this, 'nested', true);
});

/**
 * ### .own
 *
 * Causes all `.property` and `.include` assertions that follow in the chain
 * to ignore inherited properties.
 *
 *     Object.prototype.b = 2;
 *
 *     expect({a: 1}).to.have.own.property('a');
 *     expect({a: 1}).to.have.property('b');
 *     expect({a: 1}).to.not.have.own.property('b');
 *
 *     expect({a: 1}).to.own.include({a: 1});
 *     expect({a: 1}).to.include({b: 2}).but.not.own.include({b: 2});
 *
 * `.own` cannot be combined with `.nested`.
 *
 * @name own
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('own', function () {
  flag(this, 'own', true);
});

/**
 * ### .ordered
 *
 * Causes all `.members` assertions that follow in the chain to require that
 * members be in the same order.
 *
 *     expect([1, 2]).to.have.ordered.members([1, 2])
 *       .but.not.have.ordered.members([2, 1]);
 *
 * When `.include` and `.ordered` are combined, the ordering begins at the
 * start of both arrays.
 *
 *     expect([1, 2, 3]).to.include.ordered.members([1, 2])
 *       .but.not.include.ordered.members([2, 3]);
 *
 * @name ordered
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('ordered', function () {
  flag(this, 'ordered', true);
});

/**
 * ### .any
 *
 * Causes all `.keys` assertions that follow in the chain to only require that
 * the target have at least one of the given keys. This is the opposite of
 * `.all`, which requires that the target have all of the given keys.
 *
 *     expect({a: 1, b: 2}).to.not.have.any.keys('c', 'd');
 *
 * See the `.keys` doc for guidance on when to use `.any` or `.all`.
 *
 * @name any
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('any', function () {
  flag(this, 'any', true);
  flag(this, 'all', false);
});

/**
 * ### .all
 *
 * Causes all `.keys` assertions that follow in the chain to require that the
 * target have all of the given keys. This is the opposite of `.any`, which
 * only requires that the target have at least one of the given keys.
 *
 *     expect({a: 1, b: 2}).to.have.all.keys('a', 'b');
 *
 * Note that `.all` is used by default when neither `.all` nor `.any` are
 * added earlier in the chain. However, it's often best to add `.all` anyway
 * because it improves readability.
 *
 * See the `.keys` doc for guidance on when to use `.any` or `.all`.
 *
 * @name all
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('all', function () {
  flag(this, 'all', true);
  flag(this, 'any', false);
});

/**
 * ### .a(type[, msg])
 *
 * Asserts that the target's type is equal to the given string `type`. Types
 * are case insensitive. See the `type-detect` project page for info on the
 * type detection algorithm: https://github.com/chaijs/type-detect.
 *
 *     expect('foo').to.be.a('string');
 *     expect({a: 1}).to.be.an('object');
 *     expect(null).to.be.a('null');
 *     expect(undefined).to.be.an('undefined');
 *     expect(new Error).to.be.an('error');
 *     expect(Promise.resolve()).to.be.a('promise');
 *     expect(new Float32Array).to.be.a('float32array');
 *     expect(Symbol()).to.be.a('symbol');
 *
 * `.a` supports objects that have a custom type set via `Symbol.toStringTag`.
 *
 *     var myObj = {
 *       [Symbol.toStringTag]: 'myCustomType'
 *     };
 *
 *     expect(myObj).to.be.a('myCustomType').but.not.an('object');
 *
 * It's often best to use `.a` to check a target's type before making more
 * assertions on the same target. That way, you avoid unexpected behavior from
 * any assertion that does different things based on the target's type.
 *
 *     expect([1, 2, 3]).to.be.an('array').that.includes(2);
 *     expect([]).to.be.an('array').that.is.empty;
 *
 * Add `.not` earlier in the chain to negate `.a`. However, it's often best to
 * assert that the target is the expected type, rather than asserting that it
 * isn't one of many unexpected types.
 *
 *     expect('foo').to.be.a('string'); // Recommended
 *     expect('foo').to.not.be.an('array'); // Not recommended
 *
 * `.a` accepts an optional `msg` argument which is a custom error message to
 * show when the assertion fails. The message can also be given as the second
 * argument to `expect`.
 *
 *     expect(1).to.be.a('string', 'nooo why fail??');
 *     expect(1, 'nooo why fail??').to.be.a('string');
 *
 * `.a` can also be used as a language chain to improve the readability of
 * your assertions.
 *
 *     expect({b: 2}).to.have.a.property('b');
 *
 * The alias `.an` can be used interchangeably with `.a`.
 *
 * @name a
 * @alias an
 * @param {String} type
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function an (type, msg) {
  if (msg) flag(this, 'message', msg);
  type = type.toLowerCase();
  var obj = flag(this, 'object')
    , article = ~[ 'a', 'e', 'i', 'o', 'u' ].indexOf(type.charAt(0)) ? 'an ' : 'a ';

  this.assert(
      type === _.type(obj).toLowerCase()
    , 'expected #{this} to be ' + article + type
    , 'expected #{this} not to be ' + article + type
  );
}

Assertion.addChainableMethod('an', an);
Assertion.addChainableMethod('a', an);

/**
 * ### .include(val[, msg])
 *
 * When the target is a string, `.include` asserts that the given string `val`
 * is a substring of the target.
 *
 *     expect('foobar').to.include('foo');
 *
 * When the target is an array, `.include` asserts that the given `val` is a
 * member of the target.
 *
 *     expect([1, 2, 3]).to.include(2);
 *
 * When the target is an object, `.include` asserts that the given object
 * `val`'s properties are a subset of the target's properties.
 *
 *     expect({a: 1, b: 2, c: 3}).to.include({a: 1, b: 2});
 *
 * When the target is a Set or WeakSet, `.include` asserts that the given `val` is a
 * member of the target. SameValueZero equality algorithm is used.
 *
 *     expect(new Set([1, 2])).to.include(2);
 *
 * When the target is a Map, `.include` asserts that the given `val` is one of
 * the values of the target. SameValueZero equality algorithm is used.
 *
 *     expect(new Map([['a', 1], ['b', 2]])).to.include(2);
 *
 * Because `.include` does different things based on the target's type, it's
 * important to check the target's type before using `.include`. See the `.a`
 * doc for info on testing a target's type.
 *
 *     expect([1, 2, 3]).to.be.an('array').that.includes(2);
 *
 * By default, strict (`===`) equality is used to compare array members and
 * object properties. Add `.deep` earlier in the chain to use deep equality
 * instead (WeakSet targets are not supported). See the `deep-eql` project
 * page for info on the deep equality algorithm: https://github.com/chaijs/deep-eql.
 *
 *     // Target array deeply (but not strictly) includes `{a: 1}`
 *     expect([{a: 1}]).to.deep.include({a: 1});
 *     expect([{a: 1}]).to.not.include({a: 1});
 *
 *     // Target object deeply (but not strictly) includes `x: {a: 1}`
 *     expect({x: {a: 1}}).to.deep.include({x: {a: 1}});
 *     expect({x: {a: 1}}).to.not.include({x: {a: 1}});
 *
 * By default, all of the target's properties are searched when working with
 * objects. This includes properties that are inherited and/or non-enumerable.
 * Add `.own` earlier in the chain to exclude the target's inherited
 * properties from the search.
 *
 *     Object.prototype.b = 2;
 *
 *     expect({a: 1}).to.own.include({a: 1});
 *     expect({a: 1}).to.include({b: 2}).but.not.own.include({b: 2});
 *
 * Note that a target object is always only searched for `val`'s own
 * enumerable properties.
 *
 * `.deep` and `.own` can be combined.
 *
 *     expect({a: {b: 2}}).to.deep.own.include({a: {b: 2}});
 *
 * Add `.nested` earlier in the chain to enable dot- and bracket-notation when
 * referencing nested properties.
 *
 *     expect({a: {b: ['x', 'y']}}).to.nested.include({'a.b[1]': 'y'});
 *
 * If `.` or `[]` are part of an actual property name, they can be escaped by
 * adding two backslashes before them.
 *
 *     expect({'.a': {'[b]': 2}}).to.nested.include({'\\.a.\\[b\\]': 2});
 *
 * `.deep` and `.nested` can be combined.
 *
 *     expect({a: {b: [{c: 3}]}}).to.deep.nested.include({'a.b[0]': {c: 3}});
 *
 * `.own` and `.nested` cannot be combined.
 *
 * Add `.not` earlier in the chain to negate `.include`.
 *
 *     expect('foobar').to.not.include('taco');
 *     expect([1, 2, 3]).to.not.include(4);
 *
 * However, it's dangerous to negate `.include` when the target is an object.
 * The problem is that it creates uncertain expectations by asserting that the
 * target object doesn't have all of `val`'s key/value pairs but may or may
 * not have some of them. It's often best to identify the exact output that's
 * expected, and then write an assertion that only accepts that exact output.
 *
 * When the target object isn't even expected to have `val`'s keys, it's
 * often best to assert exactly that.
 *
 *     expect({c: 3}).to.not.have.any.keys('a', 'b'); // Recommended
 *     expect({c: 3}).to.not.include({a: 1, b: 2}); // Not recommended
 *
 * When the target object is expected to have `val`'s keys, it's often best to
 * assert that each of the properties has its expected value, rather than
 * asserting that each property doesn't have one of many unexpected values.
 *
 *     expect({a: 3, b: 4}).to.include({a: 3, b: 4}); // Recommended
 *     expect({a: 3, b: 4}).to.not.include({a: 1, b: 2}); // Not recommended
 *
 * `.include` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`.
 *
 *     expect([1, 2, 3]).to.include(4, 'nooo why fail??');
 *     expect([1, 2, 3], 'nooo why fail??').to.include(4);
 *
 * `.include` can also be used as a language chain, causing all `.members` and
 * `.keys` assertions that follow in the chain to require the target to be a
 * superset of the expected set, rather than an identical set. Note that
 * `.members` ignores duplicates in the subset when `.include` is added.
 *
 *     // Target object's keys are a superset of ['a', 'b'] but not identical
 *     expect({a: 1, b: 2, c: 3}).to.include.all.keys('a', 'b');
 *     expect({a: 1, b: 2, c: 3}).to.not.have.all.keys('a', 'b');
 *
 *     // Target array is a superset of [1, 2] but not identical
 *     expect([1, 2, 3]).to.include.members([1, 2]);
 *     expect([1, 2, 3]).to.not.have.members([1, 2]);
 *
 *     // Duplicates in the subset are ignored
 *     expect([1, 2, 3]).to.include.members([1, 2, 2, 2]);
 *
 * Note that adding `.any` earlier in the chain causes the `.keys` assertion
 * to ignore `.include`.
 *
 *     // Both assertions are identical
 *     expect({a: 1}).to.include.any.keys('a', 'b');
 *     expect({a: 1}).to.have.any.keys('a', 'b');
 *
 * The aliases `.includes`, `.contain`, and `.contains` can be used
 * interchangeably with `.include`.
 *
 * @name include
 * @alias contain
 * @alias includes
 * @alias contains
 * @param {Mixed} val
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function SameValueZero(a, b) {
  return (_.isNaN(a) && _.isNaN(b)) || a === b;
}

function includeChainingBehavior () {
  flag(this, 'contains', true);
}

function include (val, msg) {
  if (msg) flag(this, 'message', msg);

  var obj = flag(this, 'object')
    , objType = _.type(obj).toLowerCase()
    , flagMsg = flag(this, 'message')
    , negate = flag(this, 'negate')
    , ssfi = flag(this, 'ssfi')
    , isDeep = flag(this, 'deep')
    , descriptor = isDeep ? 'deep ' : '';

  flagMsg = flagMsg ? flagMsg + ': ' : '';

  var included = false;

  switch (objType) {
    case 'string':
      included = obj.indexOf(val) !== -1;
      break;

    case 'weakset':
      if (isDeep) {
        throw new AssertionError(
          flagMsg + 'unable to use .deep.include with WeakSet',
          undefined,
          ssfi
        );
      }

      included = obj.has(val);
      break;

    case 'map':
      var isEql = isDeep ? _.eql : SameValueZero;
      obj.forEach(function (item) {
        included = included || isEql(item, val);
      });
      break;

    case 'set':
      if (isDeep) {
        obj.forEach(function (item) {
          included = included || _.eql(item, val);
        });
      } else {
        included = obj.has(val);
      }
      break;

    case 'array':
      if (isDeep) {
        included = obj.some(function (item) {
          return _.eql(item, val);
        })
      } else {
        included = obj.indexOf(val) !== -1;
      }
      break;

    default:
      // This block is for asserting a subset of properties in an object.
      // `_.expectTypes` isn't used here because `.include` should work with
      // objects with a custom `@@toStringTag`.
      if (val !== Object(val)) {
        throw new AssertionError(
          flagMsg + 'object tested must be an array, a map, an object,'
            + ' a set, a string, or a weakset, but ' + objType + ' given',
          undefined,
          ssfi
        );
      }

      var props = Object.keys(val)
        , firstErr = null
        , numErrs = 0;

      props.forEach(function (prop) {
        var propAssertion = new Assertion(obj);
        _.transferFlags(this, propAssertion, true);
        flag(propAssertion, 'lockSsfi', true);

        if (!negate || props.length === 1) {
          propAssertion.property(prop, val[prop]);
          return;
        }

        try {
          propAssertion.property(prop, val[prop]);
        } catch (err) {
          if (!_.checkError.compatibleConstructor(err, AssertionError)) {
            throw err;
          }
          if (firstErr === null) firstErr = err;
          numErrs++;
        }
      }, this);

      // When validating .not.include with multiple properties, we only want
      // to throw an assertion error if all of the properties are included,
      // in which case we throw the first property assertion error that we
      // encountered.
      if (negate && props.length > 1 && numErrs === props.length) {
        throw firstErr;
      }
      return;
  }

  // Assert inclusion in collection or substring in a string.
  this.assert(
    included
    , 'expected #{this} to ' + descriptor + 'include ' + _.inspect(val)
    , 'expected #{this} to not ' + descriptor + 'include ' + _.inspect(val));
}

Assertion.addChainableMethod('include', include, includeChainingBehavior);
Assertion.addChainableMethod('contain', include, includeChainingBehavior);
Assertion.addChainableMethod('contains', include, includeChainingBehavior);
Assertion.addChainableMethod('includes', include, includeChainingBehavior);

/**
 * ### .ok
 *
 * Asserts that the target is a truthy value (considered `true` in boolean context).
 * However, it's often best to assert that the target is strictly (`===`) or
 * deeply equal to its expected value.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.be.ok; // Not recommended
 *
 *     expect(true).to.be.true; // Recommended
 *     expect(true).to.be.ok; // Not recommended
 *
 * Add `.not` earlier in the chain to negate `.ok`.
 *
 *     expect(0).to.equal(0); // Recommended
 *     expect(0).to.not.be.ok; // Not recommended
 *
 *     expect(false).to.be.false; // Recommended
 *     expect(false).to.not.be.ok; // Not recommended
 *
 *     expect(null).to.be.null; // Recommended
 *     expect(null).to.not.be.ok; // Not recommended
 *
 *     expect(undefined).to.be.undefined; // Recommended
 *     expect(undefined).to.not.be.ok; // Not recommended
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect(false, 'nooo why fail??').to.be.ok;
 *
 * @name ok
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('ok', function () {
  this.assert(
      flag(this, 'object')
    , 'expected #{this} to be truthy'
    , 'expected #{this} to be falsy');
});

/**
 * ### .true
 *
 * Asserts that the target is strictly (`===`) equal to `true`.
 *
 *     expect(true).to.be.true;
 *
 * Add `.not` earlier in the chain to negate `.true`. However, it's often best
 * to assert that the target is equal to its expected value, rather than not
 * equal to `true`.
 *
 *     expect(false).to.be.false; // Recommended
 *     expect(false).to.not.be.true; // Not recommended
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.not.be.true; // Not recommended
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect(false, 'nooo why fail??').to.be.true;
 *
 * @name true
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('true', function () {
  this.assert(
      true === flag(this, 'object')
    , 'expected #{this} to be true'
    , 'expected #{this} to be false'
    , flag(this, 'negate') ? false : true
  );
});

/**
 * ### .false
 *
 * Asserts that the target is strictly (`===`) equal to `false`.
 *
 *     expect(false).to.be.false;
 *
 * Add `.not` earlier in the chain to negate `.false`. However, it's often
 * best to assert that the target is equal to its expected value, rather than
 * not equal to `false`.
 *
 *     expect(true).to.be.true; // Recommended
 *     expect(true).to.not.be.false; // Not recommended
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.not.be.false; // Not recommended
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect(true, 'nooo why fail??').to.be.false;
 *
 * @name false
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('false', function () {
  this.assert(
      false === flag(this, 'object')
    , 'expected #{this} to be false'
    , 'expected #{this} to be true'
    , flag(this, 'negate') ? true : false
  );
});

/**
 * ### .null
 *
 * Asserts that the target is strictly (`===`) equal to `null`.
 *
 *     expect(null).to.be.null;
 *
 * Add `.not` earlier in the chain to negate `.null`. However, it's often best
 * to assert that the target is equal to its expected value, rather than not
 * equal to `null`.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.not.be.null; // Not recommended
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect(42, 'nooo why fail??').to.be.null;
 *
 * @name null
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('null', function () {
  this.assert(
      null === flag(this, 'object')
    , 'expected #{this} to be null'
    , 'expected #{this} not to be null'
  );
});

/**
 * ### .undefined
 *
 * Asserts that the target is strictly (`===`) equal to `undefined`.
 *
 *     expect(undefined).to.be.undefined;
 *
 * Add `.not` earlier in the chain to negate `.undefined`. However, it's often
 * best to assert that the target is equal to its expected value, rather than
 * not equal to `undefined`.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.not.be.undefined; // Not recommended
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect(42, 'nooo why fail??').to.be.undefined;
 *
 * @name undefined
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('undefined', function () {
  this.assert(
      undefined === flag(this, 'object')
    , 'expected #{this} to be undefined'
    , 'expected #{this} not to be undefined'
  );
});

/**
 * ### .NaN
 *
 * Asserts that the target is exactly `NaN`.
 *
 *     expect(NaN).to.be.NaN;
 *
 * Add `.not` earlier in the chain to negate `.NaN`. However, it's often best
 * to assert that the target is equal to its expected value, rather than not
 * equal to `NaN`.
 *
 *     expect('foo').to.equal('foo'); // Recommended
 *     expect('foo').to.not.be.NaN; // Not recommended
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect(42, 'nooo why fail??').to.be.NaN;
 *
 * @name NaN
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('NaN', function () {
  this.assert(
      _.isNaN(flag(this, 'object'))
      , 'expected #{this} to be NaN'
      , 'expected #{this} not to be NaN'
  );
});

/**
 * ### .exist
 *
 * Asserts that the target is not strictly (`===`) equal to either `null` or
 * `undefined`. However, it's often best to assert that the target is equal to
 * its expected value.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.exist; // Not recommended
 *
 *     expect(0).to.equal(0); // Recommended
 *     expect(0).to.exist; // Not recommended
 *
 * Add `.not` earlier in the chain to negate `.exist`.
 *
 *     expect(null).to.be.null; // Recommended
 *     expect(null).to.not.exist; // Not recommended
 *
 *     expect(undefined).to.be.undefined; // Recommended
 *     expect(undefined).to.not.exist; // Not recommended
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect(null, 'nooo why fail??').to.exist;
 *
 * @name exist
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('exist', function () {
  var val = flag(this, 'object');
  this.assert(
      val !== null && val !== undefined
    , 'expected #{this} to exist'
    , 'expected #{this} to not exist'
  );
});

/**
 * ### .empty
 *
 * When the target is a string or array, `.empty` asserts that the target's
 * `length` property is strictly (`===`) equal to `0`.
 *
 *     expect([]).to.be.empty;
 *     expect('').to.be.empty;
 *
 * When the target is a map or set, `.empty` asserts that the target's `size`
 * property is strictly equal to `0`.
 *
 *     expect(new Set()).to.be.empty;
 *     expect(new Map()).to.be.empty;
 *
 * When the target is a non-function object, `.empty` asserts that the target
 * doesn't have any own enumerable properties. Properties with Symbol-based
 * keys are excluded from the count.
 *
 *     expect({}).to.be.empty;
 *
 * Because `.empty` does different things based on the target's type, it's
 * important to check the target's type before using `.empty`. See the `.a`
 * doc for info on testing a target's type.
 *
 *     expect([]).to.be.an('array').that.is.empty;
 *
 * Add `.not` earlier in the chain to negate `.empty`. However, it's often
 * best to assert that the target contains its expected number of values,
 * rather than asserting that it's not empty.
 *
 *     expect([1, 2, 3]).to.have.lengthOf(3); // Recommended
 *     expect([1, 2, 3]).to.not.be.empty; // Not recommended
 *
 *     expect(new Set([1, 2, 3])).to.have.property('size', 3); // Recommended
 *     expect(new Set([1, 2, 3])).to.not.be.empty; // Not recommended
 *
 *     expect(Object.keys({a: 1})).to.have.lengthOf(1); // Recommended
 *     expect({a: 1}).to.not.be.empty; // Not recommended
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect([1, 2, 3], 'nooo why fail??').to.be.empty;
 *
 * @name empty
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('empty', function () {
  var val = flag(this, 'object')
    , ssfi = flag(this, 'ssfi')
    , flagMsg = flag(this, 'message')
    , itemsCount;

  flagMsg = flagMsg ? flagMsg + ': ' : '';

  switch (_.type(val).toLowerCase()) {
    case 'array':
    case 'string':
      itemsCount = val.length;
      break;
    case 'map':
    case 'set':
      itemsCount = val.size;
      break;
    case 'weakmap':
    case 'weakset':
      throw new AssertionError(
        flagMsg + '.empty was passed a weak collection',
        undefined,
        ssfi
      );
    case 'function':
      var msg = flagMsg + '.empty was passed a function ' + _.getName(val);
      throw new AssertionError(msg.trim(), undefined, ssfi);
    default:
      if (val !== Object(val)) {
        throw new AssertionError(
          flagMsg + '.empty was passed non-string primitive ' + _.inspect(val),
          undefined,
          ssfi
        );
      }
      itemsCount = Object.keys(val).length;
  }

  this.assert(
      0 === itemsCount
    , 'expected #{this} to be empty'
    , 'expected #{this} not to be empty'
  );
});

/**
 * ### .arguments
 *
 * Asserts that the target is an `arguments` object.
 *
 *     function test () {
 *       expect(arguments).to.be.arguments;
 *     }
 *
 *     test();
 *
 * Add `.not` earlier in the chain to negate `.arguments`. However, it's often
 * best to assert which type the target is expected to be, rather than
 * asserting that its not an `arguments` object.
 *
 *     expect('foo').to.be.a('string'); // Recommended
 *     expect('foo').to.not.be.arguments; // Not recommended
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect({}, 'nooo why fail??').to.be.arguments;
 *
 * The alias `.Arguments` can be used interchangeably with `.arguments`.
 *
 * @name arguments
 * @alias Arguments
 * @namespace BDD
 * @api public
 */

function checkArguments () {
  var obj = flag(this, 'object')
    , type = _.type(obj);
  this.assert(
      'Arguments' === type
    , 'expected #{this} to be arguments but got ' + type
    , 'expected #{this} to not be arguments'
  );
}

Assertion.addProperty('arguments', checkArguments);
Assertion.addProperty('Arguments', checkArguments);

/**
 * ### .equal(val[, msg])
 *
 * Asserts that the target is strictly (`===`) equal to the given `val`.
 *
 *     expect(1).to.equal(1);
 *     expect('foo').to.equal('foo');
 *
 * Add `.deep` earlier in the chain to use deep equality instead. See the
 * `deep-eql` project page for info on the deep equality algorithm:
 * https://github.com/chaijs/deep-eql.
 *
 *     // Target object deeply (but not strictly) equals `{a: 1}`
 *     expect({a: 1}).to.deep.equal({a: 1});
 *     expect({a: 1}).to.not.equal({a: 1});
 *
 *     // Target array deeply (but not strictly) equals `[1, 2]`
 *     expect([1, 2]).to.deep.equal([1, 2]);
 *     expect([1, 2]).to.not.equal([1, 2]);
 *
 * Add `.not` earlier in the chain to negate `.equal`. However, it's often
 * best to assert that the target is equal to its expected value, rather than
 * not equal to one of countless unexpected values.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.not.equal(2); // Not recommended
 *
 * `.equal` accepts an optional `msg` argument which is a custom error message
 * to show when the assertion fails. The message can also be given as the
 * second argument to `expect`.
 *
 *     expect(1).to.equal(2, 'nooo why fail??');
 *     expect(1, 'nooo why fail??').to.equal(2);
 *
 * The aliases `.equals` and `eq` can be used interchangeably with `.equal`.
 *
 * @name equal
 * @alias equals
 * @alias eq
 * @param {Mixed} val
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertEqual (val, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object');
  if (flag(this, 'deep')) {
    var prevLockSsfi = flag(this, 'lockSsfi');
    flag(this, 'lockSsfi', true);
    this.eql(val);
    flag(this, 'lockSsfi', prevLockSsfi);
  } else {
    this.assert(
        val === obj
      , 'expected #{this} to equal #{exp}'
      , 'expected #{this} to not equal #{exp}'
      , val
      , this._obj
      , true
    );
  }
}

Assertion.addMethod('equal', assertEqual);
Assertion.addMethod('equals', assertEqual);
Assertion.addMethod('eq', assertEqual);

/**
 * ### .eql(obj[, msg])
 *
 * Asserts that the target is deeply equal to the given `obj`. See the
 * `deep-eql` project page for info on the deep equality algorithm:
 * https://github.com/chaijs/deep-eql.
 *
 *     // Target object is deeply (but not strictly) equal to {a: 1}
 *     expect({a: 1}).to.eql({a: 1}).but.not.equal({a: 1});
 *
 *     // Target array is deeply (but not strictly) equal to [1, 2]
 *     expect([1, 2]).to.eql([1, 2]).but.not.equal([1, 2]);
 *
 * Add `.not` earlier in the chain to negate `.eql`. However, it's often best
 * to assert that the target is deeply equal to its expected value, rather
 * than not deeply equal to one of countless unexpected values.
 *
 *     expect({a: 1}).to.eql({a: 1}); // Recommended
 *     expect({a: 1}).to.not.eql({b: 2}); // Not recommended
 *
 * `.eql` accepts an optional `msg` argument which is a custom error message
 * to show when the assertion fails. The message can also be given as the
 * second argument to `expect`.
 *
 *     expect({a: 1}).to.eql({b: 2}, 'nooo why fail??');
 *     expect({a: 1}, 'nooo why fail??').to.eql({b: 2});
 *
 * The alias `.eqls` can be used interchangeably with `.eql`.
 *
 * The `.deep.equal` assertion is almost identical to `.eql` but with one
 * difference: `.deep.equal` causes deep equality comparisons to also be used
 * for any other assertions that follow in the chain.
 *
 * @name eql
 * @alias eqls
 * @param {Mixed} obj
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertEql(obj, msg) {
  if (msg) flag(this, 'message', msg);
  this.assert(
      _.eql(obj, flag(this, 'object'))
    , 'expected #{this} to deeply equal #{exp}'
    , 'expected #{this} to not deeply equal #{exp}'
    , obj
    , this._obj
    , true
  );
}

Assertion.addMethod('eql', assertEql);
Assertion.addMethod('eqls', assertEql);

/**
 * ### .above(n[, msg])
 *
 * Asserts that the target is a number or a date greater than the given number or date `n` respectively.
 * However, it's often best to assert that the target is equal to its expected
 * value.
 *
 *     expect(2).to.equal(2); // Recommended
 *     expect(2).to.be.above(1); // Not recommended
 *
 * Add `.lengthOf` earlier in the chain to assert that the target's `length`
 * or `size` is greater than the given number `n`.
 *
 *     expect('foo').to.have.lengthOf(3); // Recommended
 *     expect('foo').to.have.lengthOf.above(2); // Not recommended
 *
 *     expect([1, 2, 3]).to.have.lengthOf(3); // Recommended
 *     expect([1, 2, 3]).to.have.lengthOf.above(2); // Not recommended
 *
 * Add `.not` earlier in the chain to negate `.above`.
 *
 *     expect(2).to.equal(2); // Recommended
 *     expect(1).to.not.be.above(2); // Not recommended
 *
 * `.above` accepts an optional `msg` argument which is a custom error message
 * to show when the assertion fails. The message can also be given as the
 * second argument to `expect`.
 *
 *     expect(1).to.be.above(2, 'nooo why fail??');
 *     expect(1, 'nooo why fail??').to.be.above(2);
 *
 * The aliases `.gt` and `.greaterThan` can be used interchangeably with
 * `.above`.
 *
 * @name above
 * @alias gt
 * @alias greaterThan
 * @param {Number} n
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertAbove (n, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , doLength = flag(this, 'doLength')
    , flagMsg = flag(this, 'message')
    , msgPrefix = ((flagMsg) ? flagMsg + ': ' : '')
    , ssfi = flag(this, 'ssfi')
    , objType = _.type(obj).toLowerCase()
    , nType = _.type(n).toLowerCase()
    , errorMessage
    , shouldThrow = true;

  if (doLength && objType !== 'map' && objType !== 'set') {
    new Assertion(obj, flagMsg, ssfi, true).to.have.property('length');
  }

  if (!doLength && (objType === 'date' && nType !== 'date')) {
    errorMessage = msgPrefix + 'the argument to above must be a date';
  } else if (nType !== 'number' && (doLength || objType === 'number')) {
    errorMessage = msgPrefix + 'the argument to above must be a number';
  } else if (!doLength && (objType !== 'date' && objType !== 'number')) {
    var printObj = (objType === 'string') ? "'" + obj + "'" : obj;
    errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
  } else {
    shouldThrow = false;
  }

  if (shouldThrow) {
    throw new AssertionError(errorMessage, undefined, ssfi);
  }

  if (doLength) {
    var descriptor = 'length'
      , itemsCount;
    if (objType === 'map' || objType === 'set') {
      descriptor = 'size';
      itemsCount = obj.size;
    } else {
      itemsCount = obj.length;
    }
    this.assert(
        itemsCount > n
      , 'expected #{this} to have a ' + descriptor + ' above #{exp} but got #{act}'
      , 'expected #{this} to not have a ' + descriptor + ' above #{exp}'
      , n
      , itemsCount
    );
  } else {
    this.assert(
        obj > n
      , 'expected #{this} to be above #{exp}'
      , 'expected #{this} to be at most #{exp}'
      , n
    );
  }
}

Assertion.addMethod('above', assertAbove);
Assertion.addMethod('gt', assertAbove);
Assertion.addMethod('greaterThan', assertAbove);

/**
 * ### .least(n[, msg])
 *
 * Asserts that the target is a number or a date greater than or equal to the given
 * number or date `n` respectively. However, it's often best to assert that the target is equal to
 * its expected value.
 *
 *     expect(2).to.equal(2); // Recommended
 *     expect(2).to.be.at.least(1); // Not recommended
 *     expect(2).to.be.at.least(2); // Not recommended
 *
 * Add `.lengthOf` earlier in the chain to assert that the target's `length`
 * or `size` is greater than or equal to the given number `n`.
 *
 *     expect('foo').to.have.lengthOf(3); // Recommended
 *     expect('foo').to.have.lengthOf.at.least(2); // Not recommended
 *
 *     expect([1, 2, 3]).to.have.lengthOf(3); // Recommended
 *     expect([1, 2, 3]).to.have.lengthOf.at.least(2); // Not recommended
 *
 * Add `.not` earlier in the chain to negate `.least`.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.not.be.at.least(2); // Not recommended
 *
 * `.least` accepts an optional `msg` argument which is a custom error message
 * to show when the assertion fails. The message can also be given as the
 * second argument to `expect`.
 *
 *     expect(1).to.be.at.least(2, 'nooo why fail??');
 *     expect(1, 'nooo why fail??').to.be.at.least(2);
 *
 * The alias `.gte` can be used interchangeably with `.least`.
 *
 * @name least
 * @alias gte
 * @param {Number} n
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertLeast (n, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , doLength = flag(this, 'doLength')
    , flagMsg = flag(this, 'message')
    , msgPrefix = ((flagMsg) ? flagMsg + ': ' : '')
    , ssfi = flag(this, 'ssfi')
    , objType = _.type(obj).toLowerCase()
    , nType = _.type(n).toLowerCase()
    , errorMessage
    , shouldThrow = true;

  if (doLength && objType !== 'map' && objType !== 'set') {
    new Assertion(obj, flagMsg, ssfi, true).to.have.property('length');
  }

  if (!doLength && (objType === 'date' && nType !== 'date')) {
    errorMessage = msgPrefix + 'the argument to least must be a date';
  } else if (nType !== 'number' && (doLength || objType === 'number')) {
    errorMessage = msgPrefix + 'the argument to least must be a number';
  } else if (!doLength && (objType !== 'date' && objType !== 'number')) {
    var printObj = (objType === 'string') ? "'" + obj + "'" : obj;
    errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
  } else {
    shouldThrow = false;
  }

  if (shouldThrow) {
    throw new AssertionError(errorMessage, undefined, ssfi);
  }

  if (doLength) {
    var descriptor = 'length'
      , itemsCount;
    if (objType === 'map' || objType === 'set') {
      descriptor = 'size';
      itemsCount = obj.size;
    } else {
      itemsCount = obj.length;
    }
    this.assert(
        itemsCount >= n
      , 'expected #{this} to have a ' + descriptor + ' at least #{exp} but got #{act}'
      , 'expected #{this} to have a ' + descriptor + ' below #{exp}'
      , n
      , itemsCount
    );
  } else {
    this.assert(
        obj >= n
      , 'expected #{this} to be at least #{exp}'
      , 'expected #{this} to be below #{exp}'
      , n
    );
  }
}

Assertion.addMethod('least', assertLeast);
Assertion.addMethod('gte', assertLeast);

/**
 * ### .below(n[, msg])
 *
 * Asserts that the target is a number or a date less than the given number or date `n` respectively.
 * However, it's often best to assert that the target is equal to its expected
 * value.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.be.below(2); // Not recommended
 *
 * Add `.lengthOf` earlier in the chain to assert that the target's `length`
 * or `size` is less than the given number `n`.
 *
 *     expect('foo').to.have.lengthOf(3); // Recommended
 *     expect('foo').to.have.lengthOf.below(4); // Not recommended
 *
 *     expect([1, 2, 3]).to.have.length(3); // Recommended
 *     expect([1, 2, 3]).to.have.lengthOf.below(4); // Not recommended
 *
 * Add `.not` earlier in the chain to negate `.below`.
 *
 *     expect(2).to.equal(2); // Recommended
 *     expect(2).to.not.be.below(1); // Not recommended
 *
 * `.below` accepts an optional `msg` argument which is a custom error message
 * to show when the assertion fails. The message can also be given as the
 * second argument to `expect`.
 *
 *     expect(2).to.be.below(1, 'nooo why fail??');
 *     expect(2, 'nooo why fail??').to.be.below(1);
 *
 * The aliases `.lt` and `.lessThan` can be used interchangeably with
 * `.below`.
 *
 * @name below
 * @alias lt
 * @alias lessThan
 * @param {Number} n
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertBelow (n, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , doLength = flag(this, 'doLength')
    , flagMsg = flag(this, 'message')
    , msgPrefix = ((flagMsg) ? flagMsg + ': ' : '')
    , ssfi = flag(this, 'ssfi')
    , objType = _.type(obj).toLowerCase()
    , nType = _.type(n).toLowerCase()
    , errorMessage
    , shouldThrow = true;

  if (doLength && objType !== 'map' && objType !== 'set') {
    new Assertion(obj, flagMsg, ssfi, true).to.have.property('length');
  }

  if (!doLength && (objType === 'date' && nType !== 'date')) {
    errorMessage = msgPrefix + 'the argument to below must be a date';
  } else if (nType !== 'number' && (doLength || objType === 'number')) {
    errorMessage = msgPrefix + 'the argument to below must be a number';
  } else if (!doLength && (objType !== 'date' && objType !== 'number')) {
    var printObj = (objType === 'string') ? "'" + obj + "'" : obj;
    errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
  } else {
    shouldThrow = false;
  }

  if (shouldThrow) {
    throw new AssertionError(errorMessage, undefined, ssfi);
  }

  if (doLength) {
    var descriptor = 'length'
      , itemsCount;
    if (objType === 'map' || objType === 'set') {
      descriptor = 'size';
      itemsCount = obj.size;
    } else {
      itemsCount = obj.length;
    }
    this.assert(
        itemsCount < n
      , 'expected #{this} to have a ' + descriptor + ' below #{exp} but got #{act}'
      , 'expected #{this} to not have a ' + descriptor + ' below #{exp}'
      , n
      , itemsCount
    );
  } else {
    this.assert(
        obj < n
      , 'expected #{this} to be below #{exp}'
      , 'expected #{this} to be at least #{exp}'
      , n
    );
  }
}

Assertion.addMethod('below', assertBelow);
Assertion.addMethod('lt', assertBelow);
Assertion.addMethod('lessThan', assertBelow);

/**
 * ### .most(n[, msg])
 *
 * Asserts that the target is a number or a date less than or equal to the given number
 * or date `n` respectively. However, it's often best to assert that the target is equal to its
 * expected value.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.be.at.most(2); // Not recommended
 *     expect(1).to.be.at.most(1); // Not recommended
 *
 * Add `.lengthOf` earlier in the chain to assert that the target's `length`
 * or `size` is less than or equal to the given number `n`.
 *
 *     expect('foo').to.have.lengthOf(3); // Recommended
 *     expect('foo').to.have.lengthOf.at.most(4); // Not recommended
 *
 *     expect([1, 2, 3]).to.have.lengthOf(3); // Recommended
 *     expect([1, 2, 3]).to.have.lengthOf.at.most(4); // Not recommended
 *
 * Add `.not` earlier in the chain to negate `.most`.
 *
 *     expect(2).to.equal(2); // Recommended
 *     expect(2).to.not.be.at.most(1); // Not recommended
 *
 * `.most` accepts an optional `msg` argument which is a custom error message
 * to show when the assertion fails. The message can also be given as the
 * second argument to `expect`.
 *
 *     expect(2).to.be.at.most(1, 'nooo why fail??');
 *     expect(2, 'nooo why fail??').to.be.at.most(1);
 *
 * The alias `.lte` can be used interchangeably with `.most`.
 *
 * @name most
 * @alias lte
 * @param {Number} n
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertMost (n, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , doLength = flag(this, 'doLength')
    , flagMsg = flag(this, 'message')
    , msgPrefix = ((flagMsg) ? flagMsg + ': ' : '')
    , ssfi = flag(this, 'ssfi')
    , objType = _.type(obj).toLowerCase()
    , nType = _.type(n).toLowerCase()
    , errorMessage
    , shouldThrow = true;

  if (doLength && objType !== 'map' && objType !== 'set') {
    new Assertion(obj, flagMsg, ssfi, true).to.have.property('length');
  }

  if (!doLength && (objType === 'date' && nType !== 'date')) {
    errorMessage = msgPrefix + 'the argument to most must be a date';
  } else if (nType !== 'number' && (doLength || objType === 'number')) {
    errorMessage = msgPrefix + 'the argument to most must be a number';
  } else if (!doLength && (objType !== 'date' && objType !== 'number')) {
    var printObj = (objType === 'string') ? "'" + obj + "'" : obj;
    errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
  } else {
    shouldThrow = false;
  }

  if (shouldThrow) {
    throw new AssertionError(errorMessage, undefined, ssfi);
  }

  if (doLength) {
    var descriptor = 'length'
      , itemsCount;
    if (objType === 'map' || objType === 'set') {
      descriptor = 'size';
      itemsCount = obj.size;
    } else {
      itemsCount = obj.length;
    }
    this.assert(
        itemsCount <= n
      , 'expected #{this} to have a ' + descriptor + ' at most #{exp} but got #{act}'
      , 'expected #{this} to have a ' + descriptor + ' above #{exp}'
      , n
      , itemsCount
    );
  } else {
    this.assert(
        obj <= n
      , 'expected #{this} to be at most #{exp}'
      , 'expected #{this} to be above #{exp}'
      , n
    );
  }
}

Assertion.addMethod('most', assertMost);
Assertion.addMethod('lte', assertMost);

/**
 * ### .within(start, finish[, msg])
 *
 * Asserts that the target is a number or a date greater than or equal to the given
 * number or date `start`, and less than or equal to the given number or date `finish` respectively.
 * However, it's often best to assert that the target is equal to its expected
 * value.
 *
 *     expect(2).to.equal(2); // Recommended
 *     expect(2).to.be.within(1, 3); // Not recommended
 *     expect(2).to.be.within(2, 3); // Not recommended
 *     expect(2).to.be.within(1, 2); // Not recommended
 *
 * Add `.lengthOf` earlier in the chain to assert that the target's `length`
 * or `size` is greater than or equal to the given number `start`, and less
 * than or equal to the given number `finish`.
 *
 *     expect('foo').to.have.lengthOf(3); // Recommended
 *     expect('foo').to.have.lengthOf.within(2, 4); // Not recommended
 *
 *     expect([1, 2, 3]).to.have.lengthOf(3); // Recommended
 *     expect([1, 2, 3]).to.have.lengthOf.within(2, 4); // Not recommended
 *
 * Add `.not` earlier in the chain to negate `.within`.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.not.be.within(2, 4); // Not recommended
 *
 * `.within` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`.
 *
 *     expect(4).to.be.within(1, 3, 'nooo why fail??');
 *     expect(4, 'nooo why fail??').to.be.within(1, 3);
 *
 * @name within
 * @param {Number} start lower bound inclusive
 * @param {Number} finish upper bound inclusive
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

Assertion.addMethod('within', function (start, finish, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , doLength = flag(this, 'doLength')
    , flagMsg = flag(this, 'message')
    , msgPrefix = ((flagMsg) ? flagMsg + ': ' : '')
    , ssfi = flag(this, 'ssfi')
    , objType = _.type(obj).toLowerCase()
    , startType = _.type(start).toLowerCase()
    , finishType = _.type(finish).toLowerCase()
    , errorMessage
    , shouldThrow = true
    , range = (startType === 'date' && finishType === 'date')
        ? start.toUTCString() + '..' + finish.toUTCString()
        : start + '..' + finish;

  if (doLength && objType !== 'map' && objType !== 'set') {
    new Assertion(obj, flagMsg, ssfi, true).to.have.property('length');
  }

  if (!doLength && (objType === 'date' && (startType !== 'date' || finishType !== 'date'))) {
    errorMessage = msgPrefix + 'the arguments to within must be dates';
  } else if ((startType !== 'number' || finishType !== 'number') && (doLength || objType === 'number')) {
    errorMessage = msgPrefix + 'the arguments to within must be numbers';
  } else if (!doLength && (objType !== 'date' && objType !== 'number')) {
    var printObj = (objType === 'string') ? "'" + obj + "'" : obj;
    errorMessage = msgPrefix + 'expected ' + printObj + ' to be a number or a date';
  } else {
    shouldThrow = false;
  }

  if (shouldThrow) {
    throw new AssertionError(errorMessage, undefined, ssfi);
  }

  if (doLength) {
    var descriptor = 'length'
      , itemsCount;
    if (objType === 'map' || objType === 'set') {
      descriptor = 'size';
      itemsCount = obj.size;
    } else {
      itemsCount = obj.length;
    }
    this.assert(
        itemsCount >= start && itemsCount <= finish
      , 'expected #{this} to have a ' + descriptor + ' within ' + range
      , 'expected #{this} to not have a ' + descriptor + ' within ' + range
    );
  } else {
    this.assert(
        obj >= start && obj <= finish
      , 'expected #{this} to be within ' + range
      , 'expected #{this} to not be within ' + range
    );
  }
});

/**
 * ### .instanceof(constructor[, msg])
 *
 * Asserts that the target is an instance of the given `constructor`.
 *
 *     function Cat () { }
 *
 *     expect(new Cat()).to.be.an.instanceof(Cat);
 *     expect([1, 2]).to.be.an.instanceof(Array);
 *
 * Add `.not` earlier in the chain to negate `.instanceof`.
 *
 *     expect({a: 1}).to.not.be.an.instanceof(Array);
 *
 * `.instanceof` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`.
 *
 *     expect(1).to.be.an.instanceof(Array, 'nooo why fail??');
 *     expect(1, 'nooo why fail??').to.be.an.instanceof(Array);
 *
 * Due to limitations in ES5, `.instanceof` may not always work as expected
 * when using a transpiler such as Babel or TypeScript. In particular, it may
 * produce unexpected results when subclassing built-in object such as
 * `Array`, `Error`, and `Map`. See your transpiler's docs for details:
 *
 * - ([Babel](https://babeljs.io/docs/usage/caveats/#classes))
 * - ([TypeScript](https://github.com/Microsoft/TypeScript/wiki/Breaking-Changes#extending-built-ins-like-error-array-and-map-may-no-longer-work))
 *
 * The alias `.instanceOf` can be used interchangeably with `.instanceof`.
 *
 * @name instanceof
 * @param {Constructor} constructor
 * @param {String} msg _optional_
 * @alias instanceOf
 * @namespace BDD
 * @api public
 */

function assertInstanceOf (constructor, msg) {
  if (msg) flag(this, 'message', msg);

  var target = flag(this, 'object')
  var ssfi = flag(this, 'ssfi');
  var flagMsg = flag(this, 'message');

  try {
    var isInstanceOf = target instanceof constructor;
  } catch (err) {
    if (err instanceof TypeError) {
      flagMsg = flagMsg ? flagMsg + ': ' : '';
      throw new AssertionError(
        flagMsg + 'The instanceof assertion needs a constructor but '
          + _.type(constructor) + ' was given.',
        undefined,
        ssfi
      );
    }
    throw err;
  }

  var name = _.getName(constructor);
  if (name === null) {
    name = 'an unnamed constructor';
  }

  this.assert(
      isInstanceOf
    , 'expected #{this} to be an instance of ' + name
    , 'expected #{this} to not be an instance of ' + name
  );
};

Assertion.addMethod('instanceof', assertInstanceOf);
Assertion.addMethod('instanceOf', assertInstanceOf);

/**
 * ### .property(name[, val[, msg]])
 *
 * Asserts that the target has a property with the given key `name`.
 *
 *     expect({a: 1}).to.have.property('a');
 *
 * When `val` is provided, `.property` also asserts that the property's value
 * is equal to the given `val`.
 *
 *     expect({a: 1}).to.have.property('a', 1);
 *
 * By default, strict (`===`) equality is used. Add `.deep` earlier in the
 * chain to use deep equality instead. See the `deep-eql` project page for
 * info on the deep equality algorithm: https://github.com/chaijs/deep-eql.
 *
 *     // Target object deeply (but not strictly) has property `x: {a: 1}`
 *     expect({x: {a: 1}}).to.have.deep.property('x', {a: 1});
 *     expect({x: {a: 1}}).to.not.have.property('x', {a: 1});
 *
 * The target's enumerable and non-enumerable properties are always included
 * in the search. By default, both own and inherited properties are included.
 * Add `.own` earlier in the chain to exclude inherited properties from the
 * search.
 *
 *     Object.prototype.b = 2;
 *
 *     expect({a: 1}).to.have.own.property('a');
 *     expect({a: 1}).to.have.own.property('a', 1);
 *     expect({a: 1}).to.have.property('b');
 *     expect({a: 1}).to.not.have.own.property('b');
 *
 * `.deep` and `.own` can be combined.
 *
 *     expect({x: {a: 1}}).to.have.deep.own.property('x', {a: 1});
 *
 * Add `.nested` earlier in the chain to enable dot- and bracket-notation when
 * referencing nested properties.
 *
 *     expect({a: {b: ['x', 'y']}}).to.have.nested.property('a.b[1]');
 *     expect({a: {b: ['x', 'y']}}).to.have.nested.property('a.b[1]', 'y');
 *
 * If `.` or `[]` are part of an actual property name, they can be escaped by
 * adding two backslashes before them.
 *
 *     expect({'.a': {'[b]': 'x'}}).to.have.nested.property('\\.a.\\[b\\]');
 *
 * `.deep` and `.nested` can be combined.
 *
 *     expect({a: {b: [{c: 3}]}})
 *       .to.have.deep.nested.property('a.b[0]', {c: 3});
 *
 * `.own` and `.nested` cannot be combined.
 *
 * Add `.not` earlier in the chain to negate `.property`.
 *
 *     expect({a: 1}).to.not.have.property('b');
 *
 * However, it's dangerous to negate `.property` when providing `val`. The
 * problem is that it creates uncertain expectations by asserting that the
 * target either doesn't have a property with the given key `name`, or that it
 * does have a property with the given key `name` but its value isn't equal to
 * the given `val`. It's often best to identify the exact output that's
 * expected, and then write an assertion that only accepts that exact output.
 *
 * When the target isn't expected to have a property with the given key
 * `name`, it's often best to assert exactly that.
 *
 *     expect({b: 2}).to.not.have.property('a'); // Recommended
 *     expect({b: 2}).to.not.have.property('a', 1); // Not recommended
 *
 * When the target is expected to have a property with the given key `name`,
 * it's often best to assert that the property has its expected value, rather
 * than asserting that it doesn't have one of many unexpected values.
 *
 *     expect({a: 3}).to.have.property('a', 3); // Recommended
 *     expect({a: 3}).to.not.have.property('a', 1); // Not recommended
 *
 * `.property` changes the target of any assertions that follow in the chain
 * to be the value of the property from the original target object.
 *
 *     expect({a: 1}).to.have.property('a').that.is.a('number');
 *
 * `.property` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`. When not providing `val`, only use the
 * second form.
 *
 *     // Recommended
 *     expect({a: 1}).to.have.property('a', 2, 'nooo why fail??');
 *     expect({a: 1}, 'nooo why fail??').to.have.property('a', 2);
 *     expect({a: 1}, 'nooo why fail??').to.have.property('b');
 *
 *     // Not recommended
 *     expect({a: 1}).to.have.property('b', undefined, 'nooo why fail??');
 *
 * The above assertion isn't the same thing as not providing `val`. Instead,
 * it's asserting that the target object has a `b` property that's equal to
 * `undefined`.
 *
 * The assertions `.ownProperty` and `.haveOwnProperty` can be used
 * interchangeably with `.own.property`.
 *
 * @name property
 * @param {String} name
 * @param {Mixed} val (optional)
 * @param {String} msg _optional_
 * @returns value of property for chaining
 * @namespace BDD
 * @api public
 */

function assertProperty (name, val, msg) {
  if (msg) flag(this, 'message', msg);

  var isNested = flag(this, 'nested')
    , isOwn = flag(this, 'own')
    , flagMsg = flag(this, 'message')
    , obj = flag(this, 'object')
    , ssfi = flag(this, 'ssfi')
    , nameType = typeof name;

  flagMsg = flagMsg ? flagMsg + ': ' : '';

  if (isNested) {
    if (nameType !== 'string') {
      throw new AssertionError(
        flagMsg + 'the argument to property must be a string when using nested syntax',
        undefined,
        ssfi
      );
    }
  } else {
    if (nameType !== 'string' && nameType !== 'number' && nameType !== 'symbol') {
      throw new AssertionError(
        flagMsg + 'the argument to property must be a string, number, or symbol',
        undefined,
        ssfi
      );
    }
  }

  if (isNested && isOwn) {
    throw new AssertionError(
      flagMsg + 'The "nested" and "own" flags cannot be combined.',
      undefined,
      ssfi
    );
  }

  if (obj === null || obj === undefined) {
    throw new AssertionError(
      flagMsg + 'Target cannot be null or undefined.',
      undefined,
      ssfi
    );
  }

  var isDeep = flag(this, 'deep')
    , negate = flag(this, 'negate')
    , pathInfo = isNested ? _.getPathInfo(obj, name) : null
    , value = isNested ? pathInfo.value : obj[name];

  var descriptor = '';
  if (isDeep) descriptor += 'deep ';
  if (isOwn) descriptor += 'own ';
  if (isNested) descriptor += 'nested ';
  descriptor += 'property ';

  var hasProperty;
  if (isOwn) hasProperty = Object.prototype.hasOwnProperty.call(obj, name);
  else if (isNested) hasProperty = pathInfo.exists;
  else hasProperty = _.hasProperty(obj, name);

  // When performing a negated assertion for both name and val, merely having
  // a property with the given name isn't enough to cause the assertion to
  // fail. It must both have a property with the given name, and the value of
  // that property must equal the given val. Therefore, skip this assertion in
  // favor of the next.
  if (!negate || arguments.length === 1) {
    this.assert(
        hasProperty
      , 'expected #{this} to have ' + descriptor + _.inspect(name)
      , 'expected #{this} to not have ' + descriptor + _.inspect(name));
  }

  if (arguments.length > 1) {
    this.assert(
        hasProperty && (isDeep ? _.eql(val, value) : val === value)
      , 'expected #{this} to have ' + descriptor + _.inspect(name) + ' of #{exp}, but got #{act}'
      , 'expected #{this} to not have ' + descriptor + _.inspect(name) + ' of #{act}'
      , val
      , value
    );
  }

  flag(this, 'object', value);
}

Assertion.addMethod('property', assertProperty);

function assertOwnProperty (name, value, msg) {
  flag(this, 'own', true);
  assertProperty.apply(this, arguments);
}

Assertion.addMethod('ownProperty', assertOwnProperty);
Assertion.addMethod('haveOwnProperty', assertOwnProperty);

/**
 * ### .ownPropertyDescriptor(name[, descriptor[, msg]])
 *
 * Asserts that the target has its own property descriptor with the given key
 * `name`. Enumerable and non-enumerable properties are included in the
 * search.
 *
 *     expect({a: 1}).to.have.ownPropertyDescriptor('a');
 *
 * When `descriptor` is provided, `.ownPropertyDescriptor` also asserts that
 * the property's descriptor is deeply equal to the given `descriptor`. See
 * the `deep-eql` project page for info on the deep equality algorithm:
 * https://github.com/chaijs/deep-eql.
 *
 *     expect({a: 1}).to.have.ownPropertyDescriptor('a', {
 *       configurable: true,
 *       enumerable: true,
 *       writable: true,
 *       value: 1,
 *     });
 *
 * Add `.not` earlier in the chain to negate `.ownPropertyDescriptor`.
 *
 *     expect({a: 1}).to.not.have.ownPropertyDescriptor('b');
 *
 * However, it's dangerous to negate `.ownPropertyDescriptor` when providing
 * a `descriptor`. The problem is that it creates uncertain expectations by
 * asserting that the target either doesn't have a property descriptor with
 * the given key `name`, or that it does have a property descriptor with the
 * given key `name` but its not deeply equal to the given `descriptor`. It's
 * often best to identify the exact output that's expected, and then write an
 * assertion that only accepts that exact output.
 *
 * When the target isn't expected to have a property descriptor with the given
 * key `name`, it's often best to assert exactly that.
 *
 *     // Recommended
 *     expect({b: 2}).to.not.have.ownPropertyDescriptor('a');
 *
 *     // Not recommended
 *     expect({b: 2}).to.not.have.ownPropertyDescriptor('a', {
 *       configurable: true,
 *       enumerable: true,
 *       writable: true,
 *       value: 1,
 *     });
 *
 * When the target is expected to have a property descriptor with the given
 * key `name`, it's often best to assert that the property has its expected
 * descriptor, rather than asserting that it doesn't have one of many
 * unexpected descriptors.
 *
 *     // Recommended
 *     expect({a: 3}).to.have.ownPropertyDescriptor('a', {
 *       configurable: true,
 *       enumerable: true,
 *       writable: true,
 *       value: 3,
 *     });
 *
 *     // Not recommended
 *     expect({a: 3}).to.not.have.ownPropertyDescriptor('a', {
 *       configurable: true,
 *       enumerable: true,
 *       writable: true,
 *       value: 1,
 *     });
 *
 * `.ownPropertyDescriptor` changes the target of any assertions that follow
 * in the chain to be the value of the property descriptor from the original
 * target object.
 *
 *     expect({a: 1}).to.have.ownPropertyDescriptor('a')
 *       .that.has.property('enumerable', true);
 *
 * `.ownPropertyDescriptor` accepts an optional `msg` argument which is a
 * custom error message to show when the assertion fails. The message can also
 * be given as the second argument to `expect`. When not providing
 * `descriptor`, only use the second form.
 *
 *     // Recommended
 *     expect({a: 1}).to.have.ownPropertyDescriptor('a', {
 *       configurable: true,
 *       enumerable: true,
 *       writable: true,
 *       value: 2,
 *     }, 'nooo why fail??');
 *
 *     // Recommended
 *     expect({a: 1}, 'nooo why fail??').to.have.ownPropertyDescriptor('a', {
 *       configurable: true,
 *       enumerable: true,
 *       writable: true,
 *       value: 2,
 *     });
 *
 *     // Recommended
 *     expect({a: 1}, 'nooo why fail??').to.have.ownPropertyDescriptor('b');
 *
 *     // Not recommended
 *     expect({a: 1})
 *       .to.have.ownPropertyDescriptor('b', undefined, 'nooo why fail??');
 *
 * The above assertion isn't the same thing as not providing `descriptor`.
 * Instead, it's asserting that the target object has a `b` property
 * descriptor that's deeply equal to `undefined`.
 *
 * The alias `.haveOwnPropertyDescriptor` can be used interchangeably with
 * `.ownPropertyDescriptor`.
 *
 * @name ownPropertyDescriptor
 * @alias haveOwnPropertyDescriptor
 * @param {String} name
 * @param {Object} descriptor _optional_
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertOwnPropertyDescriptor (name, descriptor, msg) {
  if (typeof descriptor === 'string') {
    msg = descriptor;
    descriptor = null;
  }
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object');
  var actualDescriptor = Object.getOwnPropertyDescriptor(Object(obj), name);
  if (actualDescriptor && descriptor) {
    this.assert(
        _.eql(descriptor, actualDescriptor)
      , 'expected the own property descriptor for ' + _.inspect(name) + ' on #{this} to match ' + _.inspect(descriptor) + ', got ' + _.inspect(actualDescriptor)
      , 'expected the own property descriptor for ' + _.inspect(name) + ' on #{this} to not match ' + _.inspect(descriptor)
      , descriptor
      , actualDescriptor
      , true
    );
  } else {
    this.assert(
        actualDescriptor
      , 'expected #{this} to have an own property descriptor for ' + _.inspect(name)
      , 'expected #{this} to not have an own property descriptor for ' + _.inspect(name)
    );
  }
  flag(this, 'object', actualDescriptor);
}

Assertion.addMethod('ownPropertyDescriptor', assertOwnPropertyDescriptor);
Assertion.addMethod('haveOwnPropertyDescriptor', assertOwnPropertyDescriptor);

/**
 * ### .lengthOf(n[, msg])
 *
 * Asserts that the target's `length` or `size` is equal to the given number
 * `n`.
 *
 *     expect([1, 2, 3]).to.have.lengthOf(3);
 *     expect('foo').to.have.lengthOf(3);
 *     expect(new Set([1, 2, 3])).to.have.lengthOf(3);
 *     expect(new Map([['a', 1], ['b', 2], ['c', 3]])).to.have.lengthOf(3);
 *
 * Add `.not` earlier in the chain to negate `.lengthOf`. However, it's often
 * best to assert that the target's `length` property is equal to its expected
 * value, rather than not equal to one of many unexpected values.
 *
 *     expect('foo').to.have.lengthOf(3); // Recommended
 *     expect('foo').to.not.have.lengthOf(4); // Not recommended
 *
 * `.lengthOf` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`.
 *
 *     expect([1, 2, 3]).to.have.lengthOf(2, 'nooo why fail??');
 *     expect([1, 2, 3], 'nooo why fail??').to.have.lengthOf(2);
 *
 * `.lengthOf` can also be used as a language chain, causing all `.above`,
 * `.below`, `.least`, `.most`, and `.within` assertions that follow in the
 * chain to use the target's `length` property as the target. However, it's
 * often best to assert that the target's `length` property is equal to its
 * expected length, rather than asserting that its `length` property falls
 * within some range of values.
 *
 *     // Recommended
 *     expect([1, 2, 3]).to.have.lengthOf(3);
 *
 *     // Not recommended
 *     expect([1, 2, 3]).to.have.lengthOf.above(2);
 *     expect([1, 2, 3]).to.have.lengthOf.below(4);
 *     expect([1, 2, 3]).to.have.lengthOf.at.least(3);
 *     expect([1, 2, 3]).to.have.lengthOf.at.most(3);
 *     expect([1, 2, 3]).to.have.lengthOf.within(2,4);
 *
 * Due to a compatibility issue, the alias `.length` can't be chained directly
 * off of an uninvoked method such as `.a`. Therefore, `.length` can't be used
 * interchangeably with `.lengthOf` in every situation. It's recommended to
 * always use `.lengthOf` instead of `.length`.
 *
 *     expect([1, 2, 3]).to.have.a.length(3); // incompatible; throws error
 *     expect([1, 2, 3]).to.have.a.lengthOf(3);  // passes as expected
 *
 * @name lengthOf
 * @alias length
 * @param {Number} n
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertLengthChain () {
  flag(this, 'doLength', true);
}

function assertLength (n, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , objType = _.type(obj).toLowerCase()
    , flagMsg = flag(this, 'message')
    , ssfi = flag(this, 'ssfi')
    , descriptor = 'length'
    , itemsCount;

  switch (objType) {
    case 'map':
    case 'set':
      descriptor = 'size';
      itemsCount = obj.size;
      break;
    default:
      new Assertion(obj, flagMsg, ssfi, true).to.have.property('length');
      itemsCount = obj.length;
  }

  this.assert(
      itemsCount == n
    , 'expected #{this} to have a ' + descriptor + ' of #{exp} but got #{act}'
    , 'expected #{this} to not have a ' + descriptor + ' of #{act}'
    , n
    , itemsCount
  );
}

Assertion.addChainableMethod('length', assertLength, assertLengthChain);
Assertion.addChainableMethod('lengthOf', assertLength, assertLengthChain);

/**
 * ### .match(re[, msg])
 *
 * Asserts that the target matches the given regular expression `re`.
 *
 *     expect('foobar').to.match(/^foo/);
 *
 * Add `.not` earlier in the chain to negate `.match`.
 *
 *     expect('foobar').to.not.match(/taco/);
 *
 * `.match` accepts an optional `msg` argument which is a custom error message
 * to show when the assertion fails. The message can also be given as the
 * second argument to `expect`.
 *
 *     expect('foobar').to.match(/taco/, 'nooo why fail??');
 *     expect('foobar', 'nooo why fail??').to.match(/taco/);
 *
 * The alias `.matches` can be used interchangeably with `.match`.
 *
 * @name match
 * @alias matches
 * @param {RegExp} re
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */
function assertMatch(re, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object');
  this.assert(
      re.exec(obj)
    , 'expected #{this} to match ' + re
    , 'expected #{this} not to match ' + re
  );
}

Assertion.addMethod('match', assertMatch);
Assertion.addMethod('matches', assertMatch);

/**
 * ### .string(str[, msg])
 *
 * Asserts that the target string contains the given substring `str`.
 *
 *     expect('foobar').to.have.string('bar');
 *
 * Add `.not` earlier in the chain to negate `.string`.
 *
 *     expect('foobar').to.not.have.string('taco');
 *
 * `.string` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`.
 *
 *     expect('foobar').to.have.string('taco', 'nooo why fail??');
 *     expect('foobar', 'nooo why fail??').to.have.string('taco');
 *
 * @name string
 * @param {String} str
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

Assertion.addMethod('string', function (str, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , flagMsg = flag(this, 'message')
    , ssfi = flag(this, 'ssfi');
  new Assertion(obj, flagMsg, ssfi, true).is.a('string');

  this.assert(
      ~obj.indexOf(str)
    , 'expected #{this} to contain ' + _.inspect(str)
    , 'expected #{this} to not contain ' + _.inspect(str)
  );
});

/**
 * ### .keys(key1[, key2[, ...]])
 *
 * Asserts that the target object, array, map, or set has the given keys. Only
 * the target's own inherited properties are included in the search.
 *
 * When the target is an object or array, keys can be provided as one or more
 * string arguments, a single array argument, or a single object argument. In
 * the latter case, only the keys in the given object matter; the values are
 * ignored.
 *
 *     expect({a: 1, b: 2}).to.have.all.keys('a', 'b');
 *     expect(['x', 'y']).to.have.all.keys(0, 1);
 *
 *     expect({a: 1, b: 2}).to.have.all.keys(['a', 'b']);
 *     expect(['x', 'y']).to.have.all.keys([0, 1]);
 *
 *     expect({a: 1, b: 2}).to.have.all.keys({a: 4, b: 5}); // ignore 4 and 5
 *     expect(['x', 'y']).to.have.all.keys({0: 4, 1: 5}); // ignore 4 and 5
 *
 * When the target is a map or set, each key must be provided as a separate
 * argument.
 *
 *     expect(new Map([['a', 1], ['b', 2]])).to.have.all.keys('a', 'b');
 *     expect(new Set(['a', 'b'])).to.have.all.keys('a', 'b');
 *
 * Because `.keys` does different things based on the target's type, it's
 * important to check the target's type before using `.keys`. See the `.a` doc
 * for info on testing a target's type.
 *
 *     expect({a: 1, b: 2}).to.be.an('object').that.has.all.keys('a', 'b');
 *
 * By default, strict (`===`) equality is used to compare keys of maps and
 * sets. Add `.deep` earlier in the chain to use deep equality instead. See
 * the `deep-eql` project page for info on the deep equality algorithm:
 * https://github.com/chaijs/deep-eql.
 *
 *     // Target set deeply (but not strictly) has key `{a: 1}`
 *     expect(new Set([{a: 1}])).to.have.all.deep.keys([{a: 1}]);
 *     expect(new Set([{a: 1}])).to.not.have.all.keys([{a: 1}]);
 *
 * By default, the target must have all of the given keys and no more. Add
 * `.any` earlier in the chain to only require that the target have at least
 * one of the given keys. Also, add `.not` earlier in the chain to negate
 * `.keys`. It's often best to add `.any` when negating `.keys`, and to use
 * `.all` when asserting `.keys` without negation.
 *
 * When negating `.keys`, `.any` is preferred because `.not.any.keys` asserts
 * exactly what's expected of the output, whereas `.not.all.keys` creates
 * uncertain expectations.
 *
 *     // Recommended; asserts that target doesn't have any of the given keys
 *     expect({a: 1, b: 2}).to.not.have.any.keys('c', 'd');
 *
 *     // Not recommended; asserts that target doesn't have all of the given
 *     // keys but may or may not have some of them
 *     expect({a: 1, b: 2}).to.not.have.all.keys('c', 'd');
 *
 * When asserting `.keys` without negation, `.all` is preferred because
 * `.all.keys` asserts exactly what's expected of the output, whereas
 * `.any.keys` creates uncertain expectations.
 *
 *     // Recommended; asserts that target has all the given keys
 *     expect({a: 1, b: 2}).to.have.all.keys('a', 'b');
 *
 *     // Not recommended; asserts that target has at least one of the given
 *     // keys but may or may not have more of them
 *     expect({a: 1, b: 2}).to.have.any.keys('a', 'b');
 *
 * Note that `.all` is used by default when neither `.all` nor `.any` appear
 * earlier in the chain. However, it's often best to add `.all` anyway because
 * it improves readability.
 *
 *     // Both assertions are identical
 *     expect({a: 1, b: 2}).to.have.all.keys('a', 'b'); // Recommended
 *     expect({a: 1, b: 2}).to.have.keys('a', 'b'); // Not recommended
 *
 * Add `.include` earlier in the chain to require that the target's keys be a
 * superset of the expected keys, rather than identical sets.
 *
 *     // Target object's keys are a superset of ['a', 'b'] but not identical
 *     expect({a: 1, b: 2, c: 3}).to.include.all.keys('a', 'b');
 *     expect({a: 1, b: 2, c: 3}).to.not.have.all.keys('a', 'b');
 *
 * However, if `.any` and `.include` are combined, only the `.any` takes
 * effect. The `.include` is ignored in this case.
 *
 *     // Both assertions are identical
 *     expect({a: 1}).to.have.any.keys('a', 'b');
 *     expect({a: 1}).to.include.any.keys('a', 'b');
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect({a: 1}, 'nooo why fail??').to.have.key('b');
 *
 * The alias `.key` can be used interchangeably with `.keys`.
 *
 * @name keys
 * @alias key
 * @param {...String|Array|Object} keys
 * @namespace BDD
 * @api public
 */

function assertKeys (keys) {
  var obj = flag(this, 'object')
    , objType = _.type(obj)
    , keysType = _.type(keys)
    , ssfi = flag(this, 'ssfi')
    , isDeep = flag(this, 'deep')
    , str
    , deepStr = ''
    , actual
    , ok = true
    , flagMsg = flag(this, 'message');

  flagMsg = flagMsg ? flagMsg + ': ' : '';
  var mixedArgsMsg = flagMsg + 'when testing keys against an object or an array you must give a single Array|Object|String argument or multiple String arguments';

  if (objType === 'Map' || objType === 'Set') {
    deepStr = isDeep ? 'deeply ' : '';
    actual = [];

    // Map and Set '.keys' aren't supported in IE 11. Therefore, use .forEach.
    obj.forEach(function (val, key) { actual.push(key) });

    if (keysType !== 'Array') {
      keys = Array.prototype.slice.call(arguments);
    }
  } else {
    actual = _.getOwnEnumerableProperties(obj);

    switch (keysType) {
      case 'Array':
        if (arguments.length > 1) {
          throw new AssertionError(mixedArgsMsg, undefined, ssfi);
        }
        break;
      case 'Object':
        if (arguments.length > 1) {
          throw new AssertionError(mixedArgsMsg, undefined, ssfi);
        }
        keys = Object.keys(keys);
        break;
      default:
        keys = Array.prototype.slice.call(arguments);
    }

    // Only stringify non-Symbols because Symbols would become "Symbol()"
    keys = keys.map(function (val) {
      return typeof val === 'symbol' ? val : String(val);
    });
  }

  if (!keys.length) {
    throw new AssertionError(flagMsg + 'keys required', undefined, ssfi);
  }

  var len = keys.length
    , any = flag(this, 'any')
    , all = flag(this, 'all')
    , expected = keys;

  if (!any && !all) {
    all = true;
  }

  // Has any
  if (any) {
    ok = expected.some(function(expectedKey) {
      return actual.some(function(actualKey) {
        if (isDeep) {
          return _.eql(expectedKey, actualKey);
        } else {
          return expectedKey === actualKey;
        }
      });
    });
  }

  // Has all
  if (all) {
    ok = expected.every(function(expectedKey) {
      return actual.some(function(actualKey) {
        if (isDeep) {
          return _.eql(expectedKey, actualKey);
        } else {
          return expectedKey === actualKey;
        }
      });
    });

    if (!flag(this, 'contains')) {
      ok = ok && keys.length == actual.length;
    }
  }

  // Key string
  if (len > 1) {
    keys = keys.map(function(key) {
      return _.inspect(key);
    });
    var last = keys.pop();
    if (all) {
      str = keys.join(', ') + ', and ' + last;
    }
    if (any) {
      str = keys.join(', ') + ', or ' + last;
    }
  } else {
    str = _.inspect(keys[0]);
  }

  // Form
  str = (len > 1 ? 'keys ' : 'key ') + str;

  // Have / include
  str = (flag(this, 'contains') ? 'contain ' : 'have ') + str;

  // Assertion
  this.assert(
      ok
    , 'expected #{this} to ' + deepStr + str
    , 'expected #{this} to not ' + deepStr + str
    , expected.slice(0).sort(_.compareByInspect)
    , actual.sort(_.compareByInspect)
    , true
  );
}

Assertion.addMethod('keys', assertKeys);
Assertion.addMethod('key', assertKeys);

/**
 * ### .throw([errorLike], [errMsgMatcher], [msg])
 *
 * When no arguments are provided, `.throw` invokes the target function and
 * asserts that an error is thrown.
 *
 *     var badFn = function () { throw new TypeError('Illegal salmon!'); };
 *
 *     expect(badFn).to.throw();
 *
 * When one argument is provided, and it's an error constructor, `.throw`
 * invokes the target function and asserts that an error is thrown that's an
 * instance of that error constructor.
 *
 *     var badFn = function () { throw new TypeError('Illegal salmon!'); };
 *
 *     expect(badFn).to.throw(TypeError);
 *
 * When one argument is provided, and it's an error instance, `.throw` invokes
 * the target function and asserts that an error is thrown that's strictly
 * (`===`) equal to that error instance.
 *
 *     var err = new TypeError('Illegal salmon!');
 *     var badFn = function () { throw err; };
 *
 *     expect(badFn).to.throw(err);
 *
 * When one argument is provided, and it's a string, `.throw` invokes the
 * target function and asserts that an error is thrown with a message that
 * contains that string.
 *
 *     var badFn = function () { throw new TypeError('Illegal salmon!'); };
 *
 *     expect(badFn).to.throw('salmon');
 *
 * When one argument is provided, and it's a regular expression, `.throw`
 * invokes the target function and asserts that an error is thrown with a
 * message that matches that regular expression.
 *
 *     var badFn = function () { throw new TypeError('Illegal salmon!'); };
 *
 *     expect(badFn).to.throw(/salmon/);
 *
 * When two arguments are provided, and the first is an error instance or
 * constructor, and the second is a string or regular expression, `.throw`
 * invokes the function and asserts that an error is thrown that fulfills both
 * conditions as described above.
 *
 *     var err = new TypeError('Illegal salmon!');
 *     var badFn = function () { throw err; };
 *
 *     expect(badFn).to.throw(TypeError, 'salmon');
 *     expect(badFn).to.throw(TypeError, /salmon/);
 *     expect(badFn).to.throw(err, 'salmon');
 *     expect(badFn).to.throw(err, /salmon/);
 *
 * Add `.not` earlier in the chain to negate `.throw`.
 *
 *     var goodFn = function () {};
 *
 *     expect(goodFn).to.not.throw();
 *
 * However, it's dangerous to negate `.throw` when providing any arguments.
 * The problem is that it creates uncertain expectations by asserting that the
 * target either doesn't throw an error, or that it throws an error but of a
 * different type than the given type, or that it throws an error of the given
 * type but with a message that doesn't include the given string. It's often
 * best to identify the exact output that's expected, and then write an
 * assertion that only accepts that exact output.
 *
 * When the target isn't expected to throw an error, it's often best to assert
 * exactly that.
 *
 *     var goodFn = function () {};
 *
 *     expect(goodFn).to.not.throw(); // Recommended
 *     expect(goodFn).to.not.throw(ReferenceError, 'x'); // Not recommended
 *
 * When the target is expected to throw an error, it's often best to assert
 * that the error is of its expected type, and has a message that includes an
 * expected string, rather than asserting that it doesn't have one of many
 * unexpected types, and doesn't have a message that includes some string.
 *
 *     var badFn = function () { throw new TypeError('Illegal salmon!'); };
 *
 *     expect(badFn).to.throw(TypeError, 'salmon'); // Recommended
 *     expect(badFn).to.not.throw(ReferenceError, 'x'); // Not recommended
 *
 * `.throw` changes the target of any assertions that follow in the chain to
 * be the error object that's thrown.
 *
 *     var err = new TypeError('Illegal salmon!');
 *     err.code = 42;
 *     var badFn = function () { throw err; };
 *
 *     expect(badFn).to.throw(TypeError).with.property('code', 42);
 *
 * `.throw` accepts an optional `msg` argument which is a custom error message
 * to show when the assertion fails. The message can also be given as the
 * second argument to `expect`. When not providing two arguments, always use
 * the second form.
 *
 *     var goodFn = function () {};
 *
 *     expect(goodFn).to.throw(TypeError, 'x', 'nooo why fail??');
 *     expect(goodFn, 'nooo why fail??').to.throw();
 *
 * Due to limitations in ES5, `.throw` may not always work as expected when
 * using a transpiler such as Babel or TypeScript. In particular, it may
 * produce unexpected results when subclassing the built-in `Error` object and
 * then passing the subclassed constructor to `.throw`. See your transpiler's
 * docs for details:
 *
 * - ([Babel](https://babeljs.io/docs/usage/caveats/#classes))
 * - ([TypeScript](https://github.com/Microsoft/TypeScript/wiki/Breaking-Changes#extending-built-ins-like-error-array-and-map-may-no-longer-work))
 *
 * Beware of some common mistakes when using the `throw` assertion. One common
 * mistake is to accidentally invoke the function yourself instead of letting
 * the `throw` assertion invoke the function for you. For example, when
 * testing if a function named `fn` throws, provide `fn` instead of `fn()` as
 * the target for the assertion.
 *
 *     expect(fn).to.throw();     // Good! Tests `fn` as desired
 *     expect(fn()).to.throw();   // Bad! Tests result of `fn()`, not `fn`
 *
 * If you need to assert that your function `fn` throws when passed certain
 * arguments, then wrap a call to `fn` inside of another function.
 *
 *     expect(function () { fn(42); }).to.throw();  // Function expression
 *     expect(() => fn(42)).to.throw();             // ES6 arrow function
 *
 * Another common mistake is to provide an object method (or any stand-alone
 * function that relies on `this`) as the target of the assertion. Doing so is
 * problematic because the `this` context will be lost when the function is
 * invoked by `.throw`; there's no way for it to know what `this` is supposed
 * to be. There are two ways around this problem. One solution is to wrap the
 * method or function call inside of another function. Another solution is to
 * use `bind`.
 *
 *     expect(function () { cat.meow(); }).to.throw();  // Function expression
 *     expect(() => cat.meow()).to.throw();             // ES6 arrow function
 *     expect(cat.meow.bind(cat)).to.throw();           // Bind
 *
 * Finally, it's worth mentioning that it's a best practice in JavaScript to
 * only throw `Error` and derivatives of `Error` such as `ReferenceError`,
 * `TypeError`, and user-defined objects that extend `Error`. No other type of
 * value will generate a stack trace when initialized. With that said, the
 * `throw` assertion does technically support any type of value being thrown,
 * not just `Error` and its derivatives.
 *
 * The aliases `.throws` and `.Throw` can be used interchangeably with
 * `.throw`.
 *
 * @name throw
 * @alias throws
 * @alias Throw
 * @param {Error|ErrorConstructor} errorLike
 * @param {String|RegExp} errMsgMatcher error message
 * @param {String} msg _optional_
 * @see https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Error#Error_types
 * @returns error for chaining (null if no error)
 * @namespace BDD
 * @api public
 */

function assertThrows (errorLike, errMsgMatcher, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , ssfi = flag(this, 'ssfi')
    , flagMsg = flag(this, 'message')
    , negate = flag(this, 'negate') || false;
  new Assertion(obj, flagMsg, ssfi, true).is.a('function');

  if (errorLike instanceof RegExp || typeof errorLike === 'string') {
    errMsgMatcher = errorLike;
    errorLike = null;
  }

  var caughtErr;
  try {
    obj();
  } catch (err) {
    caughtErr = err;
  }

  // If we have the negate flag enabled and at least one valid argument it means we do expect an error
  // but we want it to match a given set of criteria
  var everyArgIsUndefined = errorLike === undefined && errMsgMatcher === undefined;

  // If we've got the negate flag enabled and both args, we should only fail if both aren't compatible
  // See Issue #551 and PR #683@GitHub
  var everyArgIsDefined = Boolean(errorLike && errMsgMatcher);
  var errorLikeFail = false;
  var errMsgMatcherFail = false;

  // Checking if error was thrown
  if (everyArgIsUndefined || !everyArgIsUndefined && !negate) {
    // We need this to display results correctly according to their types
    var errorLikeString = 'an error';
    if (errorLike instanceof Error) {
      errorLikeString = '#{exp}';
    } else if (errorLike) {
      errorLikeString = _.checkError.getConstructorName(errorLike);
    }

    this.assert(
        caughtErr
      , 'expected #{this} to throw ' + errorLikeString
      , 'expected #{this} to not throw an error but #{act} was thrown'
      , errorLike && errorLike.toString()
      , (caughtErr instanceof Error ?
          caughtErr.toString() : (typeof caughtErr === 'string' ? caughtErr : caughtErr &&
                                  _.checkError.getConstructorName(caughtErr)))
    );
  }

  if (errorLike && caughtErr) {
    // We should compare instances only if `errorLike` is an instance of `Error`
    if (errorLike instanceof Error) {
      var isCompatibleInstance = _.checkError.compatibleInstance(caughtErr, errorLike);

      if (isCompatibleInstance === negate) {
        // These checks were created to ensure we won't fail too soon when we've got both args and a negate
        // See Issue #551 and PR #683@GitHub
        if (everyArgIsDefined && negate) {
          errorLikeFail = true;
        } else {
          this.assert(
              negate
            , 'expected #{this} to throw #{exp} but #{act} was thrown'
            , 'expected #{this} to not throw #{exp}' + (caughtErr && !negate ? ' but #{act} was thrown' : '')
            , errorLike.toString()
            , caughtErr.toString()
          );
        }
      }
    }

    var isCompatibleConstructor = _.checkError.compatibleConstructor(caughtErr, errorLike);
    if (isCompatibleConstructor === negate) {
      if (everyArgIsDefined && negate) {
          errorLikeFail = true;
      } else {
        this.assert(
            negate
          , 'expected #{this} to throw #{exp} but #{act} was thrown'
          , 'expected #{this} to not throw #{exp}' + (caughtErr ? ' but #{act} was thrown' : '')
          , (errorLike instanceof Error ? errorLike.toString() : errorLike && _.checkError.getConstructorName(errorLike))
          , (caughtErr instanceof Error ? caughtErr.toString() : caughtErr && _.checkError.getConstructorName(caughtErr))
        );
      }
    }
  }

  if (caughtErr && errMsgMatcher !== undefined && errMsgMatcher !== null) {
    // Here we check compatible messages
    var placeholder = 'including';
    if (errMsgMatcher instanceof RegExp) {
      placeholder = 'matching'
    }

    var isCompatibleMessage = _.checkError.compatibleMessage(caughtErr, errMsgMatcher);
    if (isCompatibleMessage === negate) {
      if (everyArgIsDefined && negate) {
          errMsgMatcherFail = true;
      } else {
        this.assert(
          negate
          , 'expected #{this} to throw error ' + placeholder + ' #{exp} but got #{act}'
          , 'expected #{this} to throw error not ' + placeholder + ' #{exp}'
          ,  errMsgMatcher
          ,  _.checkError.getMessage(caughtErr)
        );
      }
    }
  }

  // If both assertions failed and both should've matched we throw an error
  if (errorLikeFail && errMsgMatcherFail) {
    this.assert(
      negate
      , 'expected #{this} to throw #{exp} but #{act} was thrown'
      , 'expected #{this} to not throw #{exp}' + (caughtErr ? ' but #{act} was thrown' : '')
      , (errorLike instanceof Error ? errorLike.toString() : errorLike && _.checkError.getConstructorName(errorLike))
      , (caughtErr instanceof Error ? caughtErr.toString() : caughtErr && _.checkError.getConstructorName(caughtErr))
    );
  }

  flag(this, 'object', caughtErr);
};

Assertion.addMethod('throw', assertThrows);
Assertion.addMethod('throws', assertThrows);
Assertion.addMethod('Throw', assertThrows);

/**
 * ### .respondTo(method[, msg])
 *
 * When the target is a non-function object, `.respondTo` asserts that the
 * target has a method with the given name `method`. The method can be own or
 * inherited, and it can be enumerable or non-enumerable.
 *
 *     function Cat () {}
 *     Cat.prototype.meow = function () {};
 *
 *     expect(new Cat()).to.respondTo('meow');
 *
 * When the target is a function, `.respondTo` asserts that the target's
 * `prototype` property has a method with the given name `method`. Again, the
 * method can be own or inherited, and it can be enumerable or non-enumerable.
 *
 *     function Cat () {}
 *     Cat.prototype.meow = function () {};
 *
 *     expect(Cat).to.respondTo('meow');
 *
 * Add `.itself` earlier in the chain to force `.respondTo` to treat the
 * target as a non-function object, even if it's a function. Thus, it asserts
 * that the target has a method with the given name `method`, rather than
 * asserting that the target's `prototype` property has a method with the
 * given name `method`.
 *
 *     function Cat () {}
 *     Cat.prototype.meow = function () {};
 *     Cat.hiss = function () {};
 *
 *     expect(Cat).itself.to.respondTo('hiss').but.not.respondTo('meow');
 *
 * When not adding `.itself`, it's important to check the target's type before
 * using `.respondTo`. See the `.a` doc for info on checking a target's type.
 *
 *     function Cat () {}
 *     Cat.prototype.meow = function () {};
 *
 *     expect(new Cat()).to.be.an('object').that.respondsTo('meow');
 *
 * Add `.not` earlier in the chain to negate `.respondTo`.
 *
 *     function Dog () {}
 *     Dog.prototype.bark = function () {};
 *
 *     expect(new Dog()).to.not.respondTo('meow');
 *
 * `.respondTo` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`.
 *
 *     expect({}).to.respondTo('meow', 'nooo why fail??');
 *     expect({}, 'nooo why fail??').to.respondTo('meow');
 *
 * The alias `.respondsTo` can be used interchangeably with `.respondTo`.
 *
 * @name respondTo
 * @alias respondsTo
 * @param {String} method
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function respondTo (method, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , itself = flag(this, 'itself')
    , context = ('function' === typeof obj && !itself)
      ? obj.prototype[method]
      : obj[method];

  this.assert(
      'function' === typeof context
    , 'expected #{this} to respond to ' + _.inspect(method)
    , 'expected #{this} to not respond to ' + _.inspect(method)
  );
}

Assertion.addMethod('respondTo', respondTo);
Assertion.addMethod('respondsTo', respondTo);

/**
 * ### .itself
 *
 * Forces all `.respondTo` assertions that follow in the chain to behave as if
 * the target is a non-function object, even if it's a function. Thus, it
 * causes `.respondTo` to assert that the target has a method with the given
 * name, rather than asserting that the target's `prototype` property has a
 * method with the given name.
 *
 *     function Cat () {}
 *     Cat.prototype.meow = function () {};
 *     Cat.hiss = function () {};
 *
 *     expect(Cat).itself.to.respondTo('hiss').but.not.respondTo('meow');
 *
 * @name itself
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('itself', function () {
  flag(this, 'itself', true);
});

/**
 * ### .satisfy(matcher[, msg])
 *
 * Invokes the given `matcher` function with the target being passed as the
 * first argument, and asserts that the value returned is truthy.
 *
 *     expect(1).to.satisfy(function(num) {
 *       return num > 0;
 *     });
 *
 * Add `.not` earlier in the chain to negate `.satisfy`.
 *
 *     expect(1).to.not.satisfy(function(num) {
 *       return num > 2;
 *     });
 *
 * `.satisfy` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`.
 *
 *     expect(1).to.satisfy(function(num) {
 *       return num > 2;
 *     }, 'nooo why fail??');
 *
 *     expect(1, 'nooo why fail??').to.satisfy(function(num) {
 *       return num > 2;
 *     });
 *
 * The alias `.satisfies` can be used interchangeably with `.satisfy`.
 *
 * @name satisfy
 * @alias satisfies
 * @param {Function} matcher
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function satisfy (matcher, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object');
  var result = matcher(obj);
  this.assert(
      result
    , 'expected #{this} to satisfy ' + _.objDisplay(matcher)
    , 'expected #{this} to not satisfy' + _.objDisplay(matcher)
    , flag(this, 'negate') ? false : true
    , result
  );
}

Assertion.addMethod('satisfy', satisfy);
Assertion.addMethod('satisfies', satisfy);

/**
 * ### .closeTo(expected, delta[, msg])
 *
 * Asserts that the target is a number that's within a given +/- `delta` range
 * of the given number `expected`. However, it's often best to assert that the
 * target is equal to its expected value.
 *
 *     // Recommended
 *     expect(1.5).to.equal(1.5);
 *
 *     // Not recommended
 *     expect(1.5).to.be.closeTo(1, 0.5);
 *     expect(1.5).to.be.closeTo(2, 0.5);
 *     expect(1.5).to.be.closeTo(1, 1);
 *
 * Add `.not` earlier in the chain to negate `.closeTo`.
 *
 *     expect(1.5).to.equal(1.5); // Recommended
 *     expect(1.5).to.not.be.closeTo(3, 1); // Not recommended
 *
 * `.closeTo` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`.
 *
 *     expect(1.5).to.be.closeTo(3, 1, 'nooo why fail??');
 *     expect(1.5, 'nooo why fail??').to.be.closeTo(3, 1);
 *
 * The alias `.approximately` can be used interchangeably with `.closeTo`.
 *
 * @name closeTo
 * @alias approximately
 * @param {Number} expected
 * @param {Number} delta
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function closeTo(expected, delta, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , flagMsg = flag(this, 'message')
    , ssfi = flag(this, 'ssfi');

  new Assertion(obj, flagMsg, ssfi, true).is.a('number');
  if (typeof expected !== 'number' || typeof delta !== 'number') {
    flagMsg = flagMsg ? flagMsg + ': ' : '';
    throw new AssertionError(
        flagMsg + 'the arguments to closeTo or approximately must be numbers',
        undefined,
        ssfi
    );
  }

  this.assert(
      Math.abs(obj - expected) <= delta
    , 'expected #{this} to be close to ' + expected + ' +/- ' + delta
    , 'expected #{this} not to be close to ' + expected + ' +/- ' + delta
  );
}

Assertion.addMethod('closeTo', closeTo);
Assertion.addMethod('approximately', closeTo);

// Note: Duplicates are ignored if testing for inclusion instead of sameness.
function isSubsetOf(subset, superset, cmp, contains, ordered) {
  if (!contains) {
    if (subset.length !== superset.length) return false;
    superset = superset.slice();
  }

  return subset.every(function(elem, idx) {
    if (ordered) return cmp ? cmp(elem, superset[idx]) : elem === superset[idx];

    if (!cmp) {
      var matchIdx = superset.indexOf(elem);
      if (matchIdx === -1) return false;

      // Remove match from superset so not counted twice if duplicate in subset.
      if (!contains) superset.splice(matchIdx, 1);
      return true;
    }

    return superset.some(function(elem2, matchIdx) {
      if (!cmp(elem, elem2)) return false;

      // Remove match from superset so not counted twice if duplicate in subset.
      if (!contains) superset.splice(matchIdx, 1);
      return true;
    });
  });
}

/**
 * ### .members(set[, msg])
 *
 * Asserts that the target array has the same members as the given array
 * `set`.
 *
 *     expect([1, 2, 3]).to.have.members([2, 1, 3]);
 *     expect([1, 2, 2]).to.have.members([2, 1, 2]);
 *
 * By default, members are compared using strict (`===`) equality. Add `.deep`
 * earlier in the chain to use deep equality instead. See the `deep-eql`
 * project page for info on the deep equality algorithm:
 * https://github.com/chaijs/deep-eql.
 *
 *     // Target array deeply (but not strictly) has member `{a: 1}`
 *     expect([{a: 1}]).to.have.deep.members([{a: 1}]);
 *     expect([{a: 1}]).to.not.have.members([{a: 1}]);
 *
 * By default, order doesn't matter. Add `.ordered` earlier in the chain to
 * require that members appear in the same order.
 *
 *     expect([1, 2, 3]).to.have.ordered.members([1, 2, 3]);
 *     expect([1, 2, 3]).to.have.members([2, 1, 3])
 *       .but.not.ordered.members([2, 1, 3]);
 *
 * By default, both arrays must be the same size. Add `.include` earlier in
 * the chain to require that the target's members be a superset of the
 * expected members. Note that duplicates are ignored in the subset when
 * `.include` is added.
 *
 *     // Target array is a superset of [1, 2] but not identical
 *     expect([1, 2, 3]).to.include.members([1, 2]);
 *     expect([1, 2, 3]).to.not.have.members([1, 2]);
 *
 *     // Duplicates in the subset are ignored
 *     expect([1, 2, 3]).to.include.members([1, 2, 2, 2]);
 *
 * `.deep`, `.ordered`, and `.include` can all be combined. However, if
 * `.include` and `.ordered` are combined, the ordering begins at the start of
 * both arrays.
 *
 *     expect([{a: 1}, {b: 2}, {c: 3}])
 *       .to.include.deep.ordered.members([{a: 1}, {b: 2}])
 *       .but.not.include.deep.ordered.members([{b: 2}, {c: 3}]);
 *
 * Add `.not` earlier in the chain to negate `.members`. However, it's
 * dangerous to do so. The problem is that it creates uncertain expectations
 * by asserting that the target array doesn't have all of the same members as
 * the given array `set` but may or may not have some of them. It's often best
 * to identify the exact output that's expected, and then write an assertion
 * that only accepts that exact output.
 *
 *     expect([1, 2]).to.not.include(3).and.not.include(4); // Recommended
 *     expect([1, 2]).to.not.have.members([3, 4]); // Not recommended
 *
 * `.members` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`.
 *
 *     expect([1, 2]).to.have.members([1, 2, 3], 'nooo why fail??');
 *     expect([1, 2], 'nooo why fail??').to.have.members([1, 2, 3]);
 *
 * @name members
 * @param {Array} set
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

Assertion.addMethod('members', function (subset, msg) {
  if (msg) flag(this, 'message', msg);
  var obj = flag(this, 'object')
    , flagMsg = flag(this, 'message')
    , ssfi = flag(this, 'ssfi');

  new Assertion(obj, flagMsg, ssfi, true).to.be.an('array');
  new Assertion(subset, flagMsg, ssfi, true).to.be.an('array');

  var contains = flag(this, 'contains');
  var ordered = flag(this, 'ordered');

  var subject, failMsg, failNegateMsg;

  if (contains) {
    subject = ordered ? 'an ordered superset' : 'a superset';
    failMsg = 'expected #{this} to be ' + subject + ' of #{exp}';
    failNegateMsg = 'expected #{this} to not be ' + subject + ' of #{exp}';
  } else {
    subject = ordered ? 'ordered members' : 'members';
    failMsg = 'expected #{this} to have the same ' + subject + ' as #{exp}';
    failNegateMsg = 'expected #{this} to not have the same ' + subject + ' as #{exp}';
  }

  var cmp = flag(this, 'deep') ? _.eql : undefined;

  this.assert(
      isSubsetOf(subset, obj, cmp, contains, ordered)
    , failMsg
    , failNegateMsg
    , subset
    , obj
    , true
  );
});

/**
 * ### .oneOf(list[, msg])
 *
 * Asserts that the target is a member of the given array `list`. However,
 * it's often best to assert that the target is equal to its expected value.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.be.oneOf([1, 2, 3]); // Not recommended
 *
 * Comparisons are performed using strict (`===`) equality.
 *
 * Add `.not` earlier in the chain to negate `.oneOf`.
 *
 *     expect(1).to.equal(1); // Recommended
 *     expect(1).to.not.be.oneOf([2, 3, 4]); // Not recommended
 *
 * `.oneOf` accepts an optional `msg` argument which is a custom error message
 * to show when the assertion fails. The message can also be given as the
 * second argument to `expect`.
 *
 *     expect(1).to.be.oneOf([2, 3, 4], 'nooo why fail??');
 *     expect(1, 'nooo why fail??').to.be.oneOf([2, 3, 4]);
 *
 * @name oneOf
 * @param {Array<*>} list
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function oneOf (list, msg) {
  if (msg) flag(this, 'message', msg);
  var expected = flag(this, 'object')
    , flagMsg = flag(this, 'message')
    , ssfi = flag(this, 'ssfi');
  new Assertion(list, flagMsg, ssfi, true).to.be.an('array');

  this.assert(
      list.indexOf(expected) > -1
    , 'expected #{this} to be one of #{exp}'
    , 'expected #{this} to not be one of #{exp}'
    , list
    , expected
  );
}

Assertion.addMethod('oneOf', oneOf);

/**
 * ### .change(subject[, prop[, msg]])
 *
 * When one argument is provided, `.change` asserts that the given function
 * `subject` returns a different value when it's invoked before the target
 * function compared to when it's invoked afterward. However, it's often best
 * to assert that `subject` is equal to its expected value.
 *
 *     var dots = ''
 *       , addDot = function () { dots += '.'; }
 *       , getDots = function () { return dots; };
 *
 *     // Recommended
 *     expect(getDots()).to.equal('');
 *     addDot();
 *     expect(getDots()).to.equal('.');
 *
 *     // Not recommended
 *     expect(addDot).to.change(getDots);
 *
 * When two arguments are provided, `.change` asserts that the value of the
 * given object `subject`'s `prop` property is different before invoking the
 * target function compared to afterward.
 *
 *     var myObj = {dots: ''}
 *       , addDot = function () { myObj.dots += '.'; };
 *
 *     // Recommended
 *     expect(myObj).to.have.property('dots', '');
 *     addDot();
 *     expect(myObj).to.have.property('dots', '.');
 *
 *     // Not recommended
 *     expect(addDot).to.change(myObj, 'dots');
 *
 * Strict (`===`) equality is used to compare before and after values.
 *
 * Add `.not` earlier in the chain to negate `.change`.
 *
 *     var dots = ''
 *       , noop = function () {}
 *       , getDots = function () { return dots; };
 *
 *     expect(noop).to.not.change(getDots);
 *
 *     var myObj = {dots: ''}
 *       , noop = function () {};
 *
 *     expect(noop).to.not.change(myObj, 'dots');
 *
 * `.change` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`. When not providing two arguments, always
 * use the second form.
 *
 *     var myObj = {dots: ''}
 *       , addDot = function () { myObj.dots += '.'; };
 *
 *     expect(addDot).to.not.change(myObj, 'dots', 'nooo why fail??');
 *
 *     var dots = ''
 *       , addDot = function () { dots += '.'; }
 *       , getDots = function () { return dots; };
 *
 *     expect(addDot, 'nooo why fail??').to.not.change(getDots);
 *
 * `.change` also causes all `.by` assertions that follow in the chain to
 * assert how much a numeric subject was increased or decreased by. However,
 * it's dangerous to use `.change.by`. The problem is that it creates
 * uncertain expectations by asserting that the subject either increases by
 * the given delta, or that it decreases by the given delta. It's often best
 * to identify the exact output that's expected, and then write an assertion
 * that only accepts that exact output.
 *
 *     var myObj = {val: 1}
 *       , addTwo = function () { myObj.val += 2; }
 *       , subtractTwo = function () { myObj.val -= 2; };
 *
 *     expect(addTwo).to.increase(myObj, 'val').by(2); // Recommended
 *     expect(addTwo).to.change(myObj, 'val').by(2); // Not recommended
 *
 *     expect(subtractTwo).to.decrease(myObj, 'val').by(2); // Recommended
 *     expect(subtractTwo).to.change(myObj, 'val').by(2); // Not recommended
 *
 * The alias `.changes` can be used interchangeably with `.change`.
 *
 * @name change
 * @alias changes
 * @param {String} subject
 * @param {String} prop name _optional_
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertChanges (subject, prop, msg) {
  if (msg) flag(this, 'message', msg);
  var fn = flag(this, 'object')
    , flagMsg = flag(this, 'message')
    , ssfi = flag(this, 'ssfi');
  new Assertion(fn, flagMsg, ssfi, true).is.a('function');

  var initial;
  if (!prop) {
    new Assertion(subject, flagMsg, ssfi, true).is.a('function');
    initial = subject();
  } else {
    new Assertion(subject, flagMsg, ssfi, true).to.have.property(prop);
    initial = subject[prop];
  }

  fn();

  var final = prop === undefined || prop === null ? subject() : subject[prop];
  var msgObj = prop === undefined || prop === null ? initial : '.' + prop;

  // This gets flagged because of the .by(delta) assertion
  flag(this, 'deltaMsgObj', msgObj);
  flag(this, 'initialDeltaValue', initial);
  flag(this, 'finalDeltaValue', final);
  flag(this, 'deltaBehavior', 'change');
  flag(this, 'realDelta', final !== initial);

  this.assert(
    initial !== final
    , 'expected ' + msgObj + ' to change'
    , 'expected ' + msgObj + ' to not change'
  );
}

Assertion.addMethod('change', assertChanges);
Assertion.addMethod('changes', assertChanges);

/**
 * ### .increase(subject[, prop[, msg]])
 *
 * When one argument is provided, `.increase` asserts that the given function
 * `subject` returns a greater number when it's invoked after invoking the
 * target function compared to when it's invoked beforehand. `.increase` also
 * causes all `.by` assertions that follow in the chain to assert how much
 * greater of a number is returned. It's often best to assert that the return
 * value increased by the expected amount, rather than asserting it increased
 * by any amount.
 *
 *     var val = 1
 *       , addTwo = function () { val += 2; }
 *       , getVal = function () { return val; };
 *
 *     expect(addTwo).to.increase(getVal).by(2); // Recommended
 *     expect(addTwo).to.increase(getVal); // Not recommended
 *
 * When two arguments are provided, `.increase` asserts that the value of the
 * given object `subject`'s `prop` property is greater after invoking the
 * target function compared to beforehand.
 *
 *     var myObj = {val: 1}
 *       , addTwo = function () { myObj.val += 2; };
 *
 *     expect(addTwo).to.increase(myObj, 'val').by(2); // Recommended
 *     expect(addTwo).to.increase(myObj, 'val'); // Not recommended
 *
 * Add `.not` earlier in the chain to negate `.increase`. However, it's
 * dangerous to do so. The problem is that it creates uncertain expectations
 * by asserting that the subject either decreases, or that it stays the same.
 * It's often best to identify the exact output that's expected, and then
 * write an assertion that only accepts that exact output.
 *
 * When the subject is expected to decrease, it's often best to assert that it
 * decreased by the expected amount.
 *
 *     var myObj = {val: 1}
 *       , subtractTwo = function () { myObj.val -= 2; };
 *
 *     expect(subtractTwo).to.decrease(myObj, 'val').by(2); // Recommended
 *     expect(subtractTwo).to.not.increase(myObj, 'val'); // Not recommended
 *
 * When the subject is expected to stay the same, it's often best to assert
 * exactly that.
 *
 *     var myObj = {val: 1}
 *       , noop = function () {};
 *
 *     expect(noop).to.not.change(myObj, 'val'); // Recommended
 *     expect(noop).to.not.increase(myObj, 'val'); // Not recommended
 *
 * `.increase` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`. When not providing two arguments, always
 * use the second form.
 *
 *     var myObj = {val: 1}
 *       , noop = function () {};
 *
 *     expect(noop).to.increase(myObj, 'val', 'nooo why fail??');
 *
 *     var val = 1
 *       , noop = function () {}
 *       , getVal = function () { return val; };
 *
 *     expect(noop, 'nooo why fail??').to.increase(getVal);
 *
 * The alias `.increases` can be used interchangeably with `.increase`.
 *
 * @name increase
 * @alias increases
 * @param {String|Function} subject
 * @param {String} prop name _optional_
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertIncreases (subject, prop, msg) {
  if (msg) flag(this, 'message', msg);
  var fn = flag(this, 'object')
    , flagMsg = flag(this, 'message')
    , ssfi = flag(this, 'ssfi');
  new Assertion(fn, flagMsg, ssfi, true).is.a('function');

  var initial;
  if (!prop) {
    new Assertion(subject, flagMsg, ssfi, true).is.a('function');
    initial = subject();
  } else {
    new Assertion(subject, flagMsg, ssfi, true).to.have.property(prop);
    initial = subject[prop];
  }

  // Make sure that the target is a number
  new Assertion(initial, flagMsg, ssfi, true).is.a('number');

  fn();

  var final = prop === undefined || prop === null ? subject() : subject[prop];
  var msgObj = prop === undefined || prop === null ? initial : '.' + prop;

  flag(this, 'deltaMsgObj', msgObj);
  flag(this, 'initialDeltaValue', initial);
  flag(this, 'finalDeltaValue', final);
  flag(this, 'deltaBehavior', 'increase');
  flag(this, 'realDelta', final - initial);

  this.assert(
    final - initial > 0
    , 'expected ' + msgObj + ' to increase'
    , 'expected ' + msgObj + ' to not increase'
  );
}

Assertion.addMethod('increase', assertIncreases);
Assertion.addMethod('increases', assertIncreases);

/**
 * ### .decrease(subject[, prop[, msg]])
 *
 * When one argument is provided, `.decrease` asserts that the given function
 * `subject` returns a lesser number when it's invoked after invoking the
 * target function compared to when it's invoked beforehand. `.decrease` also
 * causes all `.by` assertions that follow in the chain to assert how much
 * lesser of a number is returned. It's often best to assert that the return
 * value decreased by the expected amount, rather than asserting it decreased
 * by any amount.
 *
 *     var val = 1
 *       , subtractTwo = function () { val -= 2; }
 *       , getVal = function () { return val; };
 *
 *     expect(subtractTwo).to.decrease(getVal).by(2); // Recommended
 *     expect(subtractTwo).to.decrease(getVal); // Not recommended
 *
 * When two arguments are provided, `.decrease` asserts that the value of the
 * given object `subject`'s `prop` property is lesser after invoking the
 * target function compared to beforehand.
 *
 *     var myObj = {val: 1}
 *       , subtractTwo = function () { myObj.val -= 2; };
 *
 *     expect(subtractTwo).to.decrease(myObj, 'val').by(2); // Recommended
 *     expect(subtractTwo).to.decrease(myObj, 'val'); // Not recommended
 *
 * Add `.not` earlier in the chain to negate `.decrease`. However, it's
 * dangerous to do so. The problem is that it creates uncertain expectations
 * by asserting that the subject either increases, or that it stays the same.
 * It's often best to identify the exact output that's expected, and then
 * write an assertion that only accepts that exact output.
 *
 * When the subject is expected to increase, it's often best to assert that it
 * increased by the expected amount.
 *
 *     var myObj = {val: 1}
 *       , addTwo = function () { myObj.val += 2; };
 *
 *     expect(addTwo).to.increase(myObj, 'val').by(2); // Recommended
 *     expect(addTwo).to.not.decrease(myObj, 'val'); // Not recommended
 *
 * When the subject is expected to stay the same, it's often best to assert
 * exactly that.
 *
 *     var myObj = {val: 1}
 *       , noop = function () {};
 *
 *     expect(noop).to.not.change(myObj, 'val'); // Recommended
 *     expect(noop).to.not.decrease(myObj, 'val'); // Not recommended
 *
 * `.decrease` accepts an optional `msg` argument which is a custom error
 * message to show when the assertion fails. The message can also be given as
 * the second argument to `expect`. When not providing two arguments, always
 * use the second form.
 *
 *     var myObj = {val: 1}
 *       , noop = function () {};
 *
 *     expect(noop).to.decrease(myObj, 'val', 'nooo why fail??');
 *
 *     var val = 1
 *       , noop = function () {}
 *       , getVal = function () { return val; };
 *
 *     expect(noop, 'nooo why fail??').to.decrease(getVal);
 *
 * The alias `.decreases` can be used interchangeably with `.decrease`.
 *
 * @name decrease
 * @alias decreases
 * @param {String|Function} subject
 * @param {String} prop name _optional_
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertDecreases (subject, prop, msg) {
  if (msg) flag(this, 'message', msg);
  var fn = flag(this, 'object')
    , flagMsg = flag(this, 'message')
    , ssfi = flag(this, 'ssfi');
  new Assertion(fn, flagMsg, ssfi, true).is.a('function');

  var initial;
  if (!prop) {
    new Assertion(subject, flagMsg, ssfi, true).is.a('function');
    initial = subject();
  } else {
    new Assertion(subject, flagMsg, ssfi, true).to.have.property(prop);
    initial = subject[prop];
  }

  // Make sure that the target is a number
  new Assertion(initial, flagMsg, ssfi, true).is.a('number');

  fn();

  var final = prop === undefined || prop === null ? subject() : subject[prop];
  var msgObj = prop === undefined || prop === null ? initial : '.' + prop;

  flag(this, 'deltaMsgObj', msgObj);
  flag(this, 'initialDeltaValue', initial);
  flag(this, 'finalDeltaValue', final);
  flag(this, 'deltaBehavior', 'decrease');
  flag(this, 'realDelta', initial - final);

  this.assert(
    final - initial < 0
    , 'expected ' + msgObj + ' to decrease'
    , 'expected ' + msgObj + ' to not decrease'
  );
}

Assertion.addMethod('decrease', assertDecreases);
Assertion.addMethod('decreases', assertDecreases);

/**
 * ### .by(delta[, msg])
 *
 * When following an `.increase` assertion in the chain, `.by` asserts that
 * the subject of the `.increase` assertion increased by the given `delta`.
 *
 *     var myObj = {val: 1}
 *       , addTwo = function () { myObj.val += 2; };
 *
 *     expect(addTwo).to.increase(myObj, 'val').by(2);
 *
 * When following a `.decrease` assertion in the chain, `.by` asserts that the
 * subject of the `.decrease` assertion decreased by the given `delta`.
 *
 *     var myObj = {val: 1}
 *       , subtractTwo = function () { myObj.val -= 2; };
 *
 *     expect(subtractTwo).to.decrease(myObj, 'val').by(2);
 *
 * When following a `.change` assertion in the chain, `.by` asserts that the
 * subject of the `.change` assertion either increased or decreased by the
 * given `delta`. However, it's dangerous to use `.change.by`. The problem is
 * that it creates uncertain expectations. It's often best to identify the
 * exact output that's expected, and then write an assertion that only accepts
 * that exact output.
 *
 *     var myObj = {val: 1}
 *       , addTwo = function () { myObj.val += 2; }
 *       , subtractTwo = function () { myObj.val -= 2; };
 *
 *     expect(addTwo).to.increase(myObj, 'val').by(2); // Recommended
 *     expect(addTwo).to.change(myObj, 'val').by(2); // Not recommended
 *
 *     expect(subtractTwo).to.decrease(myObj, 'val').by(2); // Recommended
 *     expect(subtractTwo).to.change(myObj, 'val').by(2); // Not recommended
 *
 * Add `.not` earlier in the chain to negate `.by`. However, it's often best
 * to assert that the subject changed by its expected delta, rather than
 * asserting that it didn't change by one of countless unexpected deltas.
 *
 *     var myObj = {val: 1}
 *       , addTwo = function () { myObj.val += 2; };
 *
 *     // Recommended
 *     expect(addTwo).to.increase(myObj, 'val').by(2);
 *
 *     // Not recommended
 *     expect(addTwo).to.increase(myObj, 'val').but.not.by(3);
 *
 * `.by` accepts an optional `msg` argument which is a custom error message to
 * show when the assertion fails. The message can also be given as the second
 * argument to `expect`.
 *
 *     var myObj = {val: 1}
 *       , addTwo = function () { myObj.val += 2; };
 *
 *     expect(addTwo).to.increase(myObj, 'val').by(3, 'nooo why fail??');
 *     expect(addTwo, 'nooo why fail??').to.increase(myObj, 'val').by(3);
 *
 * @name by
 * @param {Number} delta
 * @param {String} msg _optional_
 * @namespace BDD
 * @api public
 */

function assertDelta(delta, msg) {
  if (msg) flag(this, 'message', msg);

  var msgObj = flag(this, 'deltaMsgObj');
  var initial = flag(this, 'initialDeltaValue');
  var final = flag(this, 'finalDeltaValue');
  var behavior = flag(this, 'deltaBehavior');
  var realDelta = flag(this, 'realDelta');

  var expression;
  if (behavior === 'change') {
    expression = Math.abs(final - initial) === Math.abs(delta);
  } else {
    expression = realDelta === Math.abs(delta);
  }

  this.assert(
    expression
    , 'expected ' + msgObj + ' to ' + behavior + ' by ' + delta
    , 'expected ' + msgObj + ' to not ' + behavior + ' by ' + delta
  );
}

Assertion.addMethod('by', assertDelta);

/**
 * ### .extensible
 *
 * Asserts that the target is extensible, which means that new properties can
 * be added to it. Primitives are never extensible.
 *
 *     expect({a: 1}).to.be.extensible;
 *
 * Add `.not` earlier in the chain to negate `.extensible`.
 *
 *     var nonExtensibleObject = Object.preventExtensions({})
 *       , sealedObject = Object.seal({})
 *       , frozenObject = Object.freeze({});
 *
 *     expect(nonExtensibleObject).to.not.be.extensible;
 *     expect(sealedObject).to.not.be.extensible;
 *     expect(frozenObject).to.not.be.extensible;
 *     expect(1).to.not.be.extensible;
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect(1, 'nooo why fail??').to.be.extensible;
 *
 * @name extensible
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('extensible', function() {
  var obj = flag(this, 'object');

  // In ES5, if the argument to this method is a primitive, then it will cause a TypeError.
  // In ES6, a non-object argument will be treated as if it was a non-extensible ordinary object, simply return false.
  // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/isExtensible
  // The following provides ES6 behavior for ES5 environments.

  var isExtensible = obj === Object(obj) && Object.isExtensible(obj);

  this.assert(
    isExtensible
    , 'expected #{this} to be extensible'
    , 'expected #{this} to not be extensible'
  );
});

/**
 * ### .sealed
 *
 * Asserts that the target is sealed, which means that new properties can't be
 * added to it, and its existing properties can't be reconfigured or deleted.
 * However, it's possible that its existing properties can still be reassigned
 * to different values. Primitives are always sealed.
 *
 *     var sealedObject = Object.seal({});
 *     var frozenObject = Object.freeze({});
 *
 *     expect(sealedObject).to.be.sealed;
 *     expect(frozenObject).to.be.sealed;
 *     expect(1).to.be.sealed;
 *
 * Add `.not` earlier in the chain to negate `.sealed`.
 *
 *     expect({a: 1}).to.not.be.sealed;
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect({a: 1}, 'nooo why fail??').to.be.sealed;
 *
 * @name sealed
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('sealed', function() {
  var obj = flag(this, 'object');

  // In ES5, if the argument to this method is a primitive, then it will cause a TypeError.
  // In ES6, a non-object argument will be treated as if it was a sealed ordinary object, simply return true.
  // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/isSealed
  // The following provides ES6 behavior for ES5 environments.

  var isSealed = obj === Object(obj) ? Object.isSealed(obj) : true;

  this.assert(
    isSealed
    , 'expected #{this} to be sealed'
    , 'expected #{this} to not be sealed'
  );
});

/**
 * ### .frozen
 *
 * Asserts that the target is frozen, which means that new properties can't be
 * added to it, and its existing properties can't be reassigned to different
 * values, reconfigured, or deleted. Primitives are always frozen.
 *
 *     var frozenObject = Object.freeze({});
 *
 *     expect(frozenObject).to.be.frozen;
 *     expect(1).to.be.frozen;
 *
 * Add `.not` earlier in the chain to negate `.frozen`.
 *
 *     expect({a: 1}).to.not.be.frozen;
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect({a: 1}, 'nooo why fail??').to.be.frozen;
 *
 * @name frozen
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('frozen', function() {
  var obj = flag(this, 'object');

  // In ES5, if the argument to this method is a primitive, then it will cause a TypeError.
  // In ES6, a non-object argument will be treated as if it was a frozen ordinary object, simply return true.
  // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/isFrozen
  // The following provides ES6 behavior for ES5 environments.

  var isFrozen = obj === Object(obj) ? Object.isFrozen(obj) : true;

  this.assert(
    isFrozen
    , 'expected #{this} to be frozen'
    , 'expected #{this} to not be frozen'
  );
});

/**
 * ### .finite
 *
 * Asserts that the target is a number, and isn't `NaN` or positive/negative
 * `Infinity`.
 *
 *     expect(1).to.be.finite;
 *
 * Add `.not` earlier in the chain to negate `.finite`. However, it's
 * dangerous to do so. The problem is that it creates uncertain expectations
 * by asserting that the subject either isn't a number, or that it's `NaN`, or
 * that it's positive `Infinity`, or that it's negative `Infinity`. It's often
 * best to identify the exact output that's expected, and then write an
 * assertion that only accepts that exact output.
 *
 * When the target isn't expected to be a number, it's often best to assert
 * that it's the expected type, rather than asserting that it isn't one of
 * many unexpected types.
 *
 *     expect('foo').to.be.a('string'); // Recommended
 *     expect('foo').to.not.be.finite; // Not recommended
 *
 * When the target is expected to be `NaN`, it's often best to assert exactly
 * that.
 *
 *     expect(NaN).to.be.NaN; // Recommended
 *     expect(NaN).to.not.be.finite; // Not recommended
 *
 * When the target is expected to be positive infinity, it's often best to
 * assert exactly that.
 *
 *     expect(Infinity).to.equal(Infinity); // Recommended
 *     expect(Infinity).to.not.be.finite; // Not recommended
 *
 * When the target is expected to be negative infinity, it's often best to
 * assert exactly that.
 *
 *     expect(-Infinity).to.equal(-Infinity); // Recommended
 *     expect(-Infinity).to.not.be.finite; // Not recommended
 *
 * A custom error message can be given as the second argument to `expect`.
 *
 *     expect('foo', 'nooo why fail??').to.be.finite;
 *
 * @name finite
 * @namespace BDD
 * @api public
 */

Assertion.addProperty('finite', function(msg) {
  var obj = flag(this, 'object');

  this.assert(
      typeof obj === 'number' && isFinite(obj)
    , 'expected #{this} to be a finite number'
    , 'expected #{this} to not be a finite number'
  );
});

};

},{}],6:[function(require,module,exports){ /*!

* chai
* Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

module.exports = function (chai, util) {

 /*!
  * Chai dependencies.
  */

 var Assertion = chai.Assertion
   , flag = util.flag;

 /*!
  * Module export.
  */

 /**
  * ### assert(expression, message)
  *
  * Write your own test expressions.
  *
  *     assert('foo' !== 'bar', 'foo is not bar');
  *     assert(Array.isArray([]), 'empty arrays are arrays');
  *
  * @param {Mixed} expression to test for truthiness
  * @param {String} message to display on error
  * @name assert
  * @namespace Assert
  * @api public
  */

 var assert = chai.assert = function (express, errmsg) {
   var test = new Assertion(null, null, chai.assert, true);
   test.assert(
       express
     , errmsg
     , '[ negation message unavailable ]'
   );
 };

 /**
  * ### .fail([message])
  * ### .fail(actual, expected, [message], [operator])
  *
  * Throw a failure. Node.js `assert` module-compatible.
  *
  *     assert.fail();
  *     assert.fail("custom error message");
  *     assert.fail(1, 2);
  *     assert.fail(1, 2, "custom error message");
  *     assert.fail(1, 2, "custom error message", ">");
  *     assert.fail(1, 2, undefined, ">");
  *
  * @name fail
  * @param {Mixed} actual
  * @param {Mixed} expected
  * @param {String} message
  * @param {String} operator
  * @namespace Assert
  * @api public
  */

 assert.fail = function (actual, expected, message, operator) {
   if (arguments.length < 2) {
       // Comply with Node's fail([message]) interface

       message = actual;
       actual = undefined;
   }

   message = message || 'assert.fail()';
   throw new chai.AssertionError(message, {
       actual: actual
     , expected: expected
     , operator: operator
   }, assert.fail);
 };

 /**
  * ### .isOk(object, [message])
  *
  * Asserts that `object` is truthy.
  *
  *     assert.isOk('everything', 'everything is ok');
  *     assert.isOk(false, 'this will fail');
  *
  * @name isOk
  * @alias ok
  * @param {Mixed} object to test
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isOk = function (val, msg) {
   new Assertion(val, msg, assert.isOk, true).is.ok;
 };

 /**
  * ### .isNotOk(object, [message])
  *
  * Asserts that `object` is falsy.
  *
  *     assert.isNotOk('everything', 'this will fail');
  *     assert.isNotOk(false, 'this will pass');
  *
  * @name isNotOk
  * @alias notOk
  * @param {Mixed} object to test
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNotOk = function (val, msg) {
   new Assertion(val, msg, assert.isNotOk, true).is.not.ok;
 };

 /**
  * ### .equal(actual, expected, [message])
  *
  * Asserts non-strict equality (`==`) of `actual` and `expected`.
  *
  *     assert.equal(3, '3', '== coerces values to strings');
  *
  * @name equal
  * @param {Mixed} actual
  * @param {Mixed} expected
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.equal = function (act, exp, msg) {
   var test = new Assertion(act, msg, assert.equal, true);

   test.assert(
       exp == flag(test, 'object')
     , 'expected #{this} to equal #{exp}'
     , 'expected #{this} to not equal #{act}'
     , exp
     , act
     , true
   );
 };

 /**
  * ### .notEqual(actual, expected, [message])
  *
  * Asserts non-strict inequality (`!=`) of `actual` and `expected`.
  *
  *     assert.notEqual(3, 4, 'these numbers are not equal');
  *
  * @name notEqual
  * @param {Mixed} actual
  * @param {Mixed} expected
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notEqual = function (act, exp, msg) {
   var test = new Assertion(act, msg, assert.notEqual, true);

   test.assert(
       exp != flag(test, 'object')
     , 'expected #{this} to not equal #{exp}'
     , 'expected #{this} to equal #{act}'
     , exp
     , act
     , true
   );
 };

 /**
  * ### .strictEqual(actual, expected, [message])
  *
  * Asserts strict equality (`===`) of `actual` and `expected`.
  *
  *     assert.strictEqual(true, true, 'these booleans are strictly equal');
  *
  * @name strictEqual
  * @param {Mixed} actual
  * @param {Mixed} expected
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.strictEqual = function (act, exp, msg) {
   new Assertion(act, msg, assert.strictEqual, true).to.equal(exp);
 };

 /**
  * ### .notStrictEqual(actual, expected, [message])
  *
  * Asserts strict inequality (`!==`) of `actual` and `expected`.
  *
  *     assert.notStrictEqual(3, '3', 'no coercion for strict equality');
  *
  * @name notStrictEqual
  * @param {Mixed} actual
  * @param {Mixed} expected
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notStrictEqual = function (act, exp, msg) {
   new Assertion(act, msg, assert.notStrictEqual, true).to.not.equal(exp);
 };

 /**
  * ### .deepEqual(actual, expected, [message])
  *
  * Asserts that `actual` is deeply equal to `expected`.
  *
  *     assert.deepEqual({ tea: 'green' }, { tea: 'green' });
  *
  * @name deepEqual
  * @param {Mixed} actual
  * @param {Mixed} expected
  * @param {String} message
  * @alias deepStrictEqual
  * @namespace Assert
  * @api public
  */

 assert.deepEqual = assert.deepStrictEqual = function (act, exp, msg) {
   new Assertion(act, msg, assert.deepEqual, true).to.eql(exp);
 };

 /**
  * ### .notDeepEqual(actual, expected, [message])
  *
  * Assert that `actual` is not deeply equal to `expected`.
  *
  *     assert.notDeepEqual({ tea: 'green' }, { tea: 'jasmine' });
  *
  * @name notDeepEqual
  * @param {Mixed} actual
  * @param {Mixed} expected
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notDeepEqual = function (act, exp, msg) {
   new Assertion(act, msg, assert.notDeepEqual, true).to.not.eql(exp);
 };

  /**
  * ### .isAbove(valueToCheck, valueToBeAbove, [message])
  *
  * Asserts `valueToCheck` is strictly greater than (>) `valueToBeAbove`.
  *
  *     assert.isAbove(5, 2, '5 is strictly greater than 2');
  *
  * @name isAbove
  * @param {Mixed} valueToCheck
  * @param {Mixed} valueToBeAbove
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isAbove = function (val, abv, msg) {
   new Assertion(val, msg, assert.isAbove, true).to.be.above(abv);
 };

  /**
  * ### .isAtLeast(valueToCheck, valueToBeAtLeast, [message])
  *
  * Asserts `valueToCheck` is greater than or equal to (>=) `valueToBeAtLeast`.
  *
  *     assert.isAtLeast(5, 2, '5 is greater or equal to 2');
  *     assert.isAtLeast(3, 3, '3 is greater or equal to 3');
  *
  * @name isAtLeast
  * @param {Mixed} valueToCheck
  * @param {Mixed} valueToBeAtLeast
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isAtLeast = function (val, atlst, msg) {
   new Assertion(val, msg, assert.isAtLeast, true).to.be.least(atlst);
 };

  /**
  * ### .isBelow(valueToCheck, valueToBeBelow, [message])
  *
  * Asserts `valueToCheck` is strictly less than (<) `valueToBeBelow`.
  *
  *     assert.isBelow(3, 6, '3 is strictly less than 6');
  *
  * @name isBelow
  * @param {Mixed} valueToCheck
  * @param {Mixed} valueToBeBelow
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isBelow = function (val, blw, msg) {
   new Assertion(val, msg, assert.isBelow, true).to.be.below(blw);
 };

  /**
  * ### .isAtMost(valueToCheck, valueToBeAtMost, [message])
  *
  * Asserts `valueToCheck` is less than or equal to (<=) `valueToBeAtMost`.
  *
  *     assert.isAtMost(3, 6, '3 is less than or equal to 6');
  *     assert.isAtMost(4, 4, '4 is less than or equal to 4');
  *
  * @name isAtMost
  * @param {Mixed} valueToCheck
  * @param {Mixed} valueToBeAtMost
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isAtMost = function (val, atmst, msg) {
   new Assertion(val, msg, assert.isAtMost, true).to.be.most(atmst);
 };

 /**
  * ### .isTrue(value, [message])
  *
  * Asserts that `value` is true.
  *
  *     var teaServed = true;
  *     assert.isTrue(teaServed, 'the tea has been served');
  *
  * @name isTrue
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isTrue = function (val, msg) {
   new Assertion(val, msg, assert.isTrue, true).is['true'];
 };

 /**
  * ### .isNotTrue(value, [message])
  *
  * Asserts that `value` is not true.
  *
  *     var tea = 'tasty chai';
  *     assert.isNotTrue(tea, 'great, time for tea!');
  *
  * @name isNotTrue
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNotTrue = function (val, msg) {
   new Assertion(val, msg, assert.isNotTrue, true).to.not.equal(true);
 };

 /**
  * ### .isFalse(value, [message])
  *
  * Asserts that `value` is false.
  *
  *     var teaServed = false;
  *     assert.isFalse(teaServed, 'no tea yet? hmm...');
  *
  * @name isFalse
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isFalse = function (val, msg) {
   new Assertion(val, msg, assert.isFalse, true).is['false'];
 };

 /**
  * ### .isNotFalse(value, [message])
  *
  * Asserts that `value` is not false.
  *
  *     var tea = 'tasty chai';
  *     assert.isNotFalse(tea, 'great, time for tea!');
  *
  * @name isNotFalse
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNotFalse = function (val, msg) {
   new Assertion(val, msg, assert.isNotFalse, true).to.not.equal(false);
 };

 /**
  * ### .isNull(value, [message])
  *
  * Asserts that `value` is null.
  *
  *     assert.isNull(err, 'there was no error');
  *
  * @name isNull
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNull = function (val, msg) {
   new Assertion(val, msg, assert.isNull, true).to.equal(null);
 };

 /**
  * ### .isNotNull(value, [message])
  *
  * Asserts that `value` is not null.
  *
  *     var tea = 'tasty chai';
  *     assert.isNotNull(tea, 'great, time for tea!');
  *
  * @name isNotNull
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNotNull = function (val, msg) {
   new Assertion(val, msg, assert.isNotNull, true).to.not.equal(null);
 };

 /**
  * ### .isNaN
  *
  * Asserts that value is NaN.
  *
  *     assert.isNaN(NaN, 'NaN is NaN');
  *
  * @name isNaN
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNaN = function (val, msg) {
   new Assertion(val, msg, assert.isNaN, true).to.be.NaN;
 };

 /**
  * ### .isNotNaN
  *
  * Asserts that value is not NaN.
  *
  *     assert.isNotNaN(4, '4 is not NaN');
  *
  * @name isNotNaN
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */
 assert.isNotNaN = function (val, msg) {
   new Assertion(val, msg, assert.isNotNaN, true).not.to.be.NaN;
 };

 /**
  * ### .exists
  *
  * Asserts that the target is neither `null` nor `undefined`.
  *
  *     var foo = 'hi';
  *
  *     assert.exists(foo, 'foo is neither `null` nor `undefined`');
  *
  * @name exists
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.exists = function (val, msg) {
   new Assertion(val, msg, assert.exists, true).to.exist;
 };

 /**
  * ### .notExists
  *
  * Asserts that the target is either `null` or `undefined`.
  *
  *     var bar = null
  *       , baz;
  *
  *     assert.notExists(bar);
  *     assert.notExists(baz, 'baz is either null or undefined');
  *
  * @name notExists
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notExists = function (val, msg) {
   new Assertion(val, msg, assert.notExists, true).to.not.exist;
 };

 /**
  * ### .isUndefined(value, [message])
  *
  * Asserts that `value` is `undefined`.
  *
  *     var tea;
  *     assert.isUndefined(tea, 'no tea defined');
  *
  * @name isUndefined
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isUndefined = function (val, msg) {
   new Assertion(val, msg, assert.isUndefined, true).to.equal(undefined);
 };

 /**
  * ### .isDefined(value, [message])
  *
  * Asserts that `value` is not `undefined`.
  *
  *     var tea = 'cup of chai';
  *     assert.isDefined(tea, 'tea has been defined');
  *
  * @name isDefined
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isDefined = function (val, msg) {
   new Assertion(val, msg, assert.isDefined, true).to.not.equal(undefined);
 };

 /**
  * ### .isFunction(value, [message])
  *
  * Asserts that `value` is a function.
  *
  *     function serveTea() { return 'cup of tea'; };
  *     assert.isFunction(serveTea, 'great, we can have tea now');
  *
  * @name isFunction
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isFunction = function (val, msg) {
   new Assertion(val, msg, assert.isFunction, true).to.be.a('function');
 };

 /**
  * ### .isNotFunction(value, [message])
  *
  * Asserts that `value` is _not_ a function.
  *
  *     var serveTea = [ 'heat', 'pour', 'sip' ];
  *     assert.isNotFunction(serveTea, 'great, we have listed the steps');
  *
  * @name isNotFunction
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNotFunction = function (val, msg) {
   new Assertion(val, msg, assert.isNotFunction, true).to.not.be.a('function');
 };

 /**
  * ### .isObject(value, [message])
  *
  * Asserts that `value` is an object of type 'Object' (as revealed by `Object.prototype.toString`).
  * _The assertion does not match subclassed objects._
  *
  *     var selection = { name: 'Chai', serve: 'with spices' };
  *     assert.isObject(selection, 'tea selection is an object');
  *
  * @name isObject
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isObject = function (val, msg) {
   new Assertion(val, msg, assert.isObject, true).to.be.a('object');
 };

 /**
  * ### .isNotObject(value, [message])
  *
  * Asserts that `value` is _not_ an object of type 'Object' (as revealed by `Object.prototype.toString`).
  *
  *     var selection = 'chai'
  *     assert.isNotObject(selection, 'tea selection is not an object');
  *     assert.isNotObject(null, 'null is not an object');
  *
  * @name isNotObject
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNotObject = function (val, msg) {
   new Assertion(val, msg, assert.isNotObject, true).to.not.be.a('object');
 };

 /**
  * ### .isArray(value, [message])
  *
  * Asserts that `value` is an array.
  *
  *     var menu = [ 'green', 'chai', 'oolong' ];
  *     assert.isArray(menu, 'what kind of tea do we want?');
  *
  * @name isArray
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isArray = function (val, msg) {
   new Assertion(val, msg, assert.isArray, true).to.be.an('array');
 };

 /**
  * ### .isNotArray(value, [message])
  *
  * Asserts that `value` is _not_ an array.
  *
  *     var menu = 'green|chai|oolong';
  *     assert.isNotArray(menu, 'what kind of tea do we want?');
  *
  * @name isNotArray
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNotArray = function (val, msg) {
   new Assertion(val, msg, assert.isNotArray, true).to.not.be.an('array');
 };

 /**
  * ### .isString(value, [message])
  *
  * Asserts that `value` is a string.
  *
  *     var teaOrder = 'chai';
  *     assert.isString(teaOrder, 'order placed');
  *
  * @name isString
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isString = function (val, msg) {
   new Assertion(val, msg, assert.isString, true).to.be.a('string');
 };

 /**
  * ### .isNotString(value, [message])
  *
  * Asserts that `value` is _not_ a string.
  *
  *     var teaOrder = 4;
  *     assert.isNotString(teaOrder, 'order placed');
  *
  * @name isNotString
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNotString = function (val, msg) {
   new Assertion(val, msg, assert.isNotString, true).to.not.be.a('string');
 };

 /**
  * ### .isNumber(value, [message])
  *
  * Asserts that `value` is a number.
  *
  *     var cups = 2;
  *     assert.isNumber(cups, 'how many cups');
  *
  * @name isNumber
  * @param {Number} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNumber = function (val, msg) {
   new Assertion(val, msg, assert.isNumber, true).to.be.a('number');
 };

 /**
  * ### .isNotNumber(value, [message])
  *
  * Asserts that `value` is _not_ a number.
  *
  *     var cups = '2 cups please';
  *     assert.isNotNumber(cups, 'how many cups');
  *
  * @name isNotNumber
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNotNumber = function (val, msg) {
   new Assertion(val, msg, assert.isNotNumber, true).to.not.be.a('number');
 };

  /**
  * ### .isFinite(value, [message])
  *
  * Asserts that `value` is a finite number. Unlike `.isNumber`, this will fail for `NaN` and `Infinity`.
  *
  *     var cups = 2;
  *     assert.isFinite(cups, 'how many cups');
  *
  *     assert.isFinite(NaN); // throws
  *
  * @name isFinite
  * @param {Number} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isFinite = function (val, msg) {
   new Assertion(val, msg, assert.isFinite, true).to.be.finite;
 };

 /**
  * ### .isBoolean(value, [message])
  *
  * Asserts that `value` is a boolean.
  *
  *     var teaReady = true
  *       , teaServed = false;
  *
  *     assert.isBoolean(teaReady, 'is the tea ready');
  *     assert.isBoolean(teaServed, 'has tea been served');
  *
  * @name isBoolean
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isBoolean = function (val, msg) {
   new Assertion(val, msg, assert.isBoolean, true).to.be.a('boolean');
 };

 /**
  * ### .isNotBoolean(value, [message])
  *
  * Asserts that `value` is _not_ a boolean.
  *
  *     var teaReady = 'yep'
  *       , teaServed = 'nope';
  *
  *     assert.isNotBoolean(teaReady, 'is the tea ready');
  *     assert.isNotBoolean(teaServed, 'has tea been served');
  *
  * @name isNotBoolean
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.isNotBoolean = function (val, msg) {
   new Assertion(val, msg, assert.isNotBoolean, true).to.not.be.a('boolean');
 };

 /**
  * ### .typeOf(value, name, [message])
  *
  * Asserts that `value`'s type is `name`, as determined by
  * `Object.prototype.toString`.
  *
  *     assert.typeOf({ tea: 'chai' }, 'object', 'we have an object');
  *     assert.typeOf(['chai', 'jasmine'], 'array', 'we have an array');
  *     assert.typeOf('tea', 'string', 'we have a string');
  *     assert.typeOf(/tea/, 'regexp', 'we have a regular expression');
  *     assert.typeOf(null, 'null', 'we have a null');
  *     assert.typeOf(undefined, 'undefined', 'we have an undefined');
  *
  * @name typeOf
  * @param {Mixed} value
  * @param {String} name
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.typeOf = function (val, type, msg) {
   new Assertion(val, msg, assert.typeOf, true).to.be.a(type);
 };

 /**
  * ### .notTypeOf(value, name, [message])
  *
  * Asserts that `value`'s type is _not_ `name`, as determined by
  * `Object.prototype.toString`.
  *
  *     assert.notTypeOf('tea', 'number', 'strings are not numbers');
  *
  * @name notTypeOf
  * @param {Mixed} value
  * @param {String} typeof name
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notTypeOf = function (val, type, msg) {
   new Assertion(val, msg, assert.notTypeOf, true).to.not.be.a(type);
 };

 /**
  * ### .instanceOf(object, constructor, [message])
  *
  * Asserts that `value` is an instance of `constructor`.
  *
  *     var Tea = function (name) { this.name = name; }
  *       , chai = new Tea('chai');
  *
  *     assert.instanceOf(chai, Tea, 'chai is an instance of tea');
  *
  * @name instanceOf
  * @param {Object} object
  * @param {Constructor} constructor
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.instanceOf = function (val, type, msg) {
   new Assertion(val, msg, assert.instanceOf, true).to.be.instanceOf(type);
 };

 /**
  * ### .notInstanceOf(object, constructor, [message])
  *
  * Asserts `value` is not an instance of `constructor`.
  *
  *     var Tea = function (name) { this.name = name; }
  *       , chai = new String('chai');
  *
  *     assert.notInstanceOf(chai, Tea, 'chai is not an instance of tea');
  *
  * @name notInstanceOf
  * @param {Object} object
  * @param {Constructor} constructor
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notInstanceOf = function (val, type, msg) {
   new Assertion(val, msg, assert.notInstanceOf, true)
     .to.not.be.instanceOf(type);
 };

 /**
  * ### .include(haystack, needle, [message])
  *
  * Asserts that `haystack` includes `needle`. Can be used to assert the
  * inclusion of a value in an array, a substring in a string, or a subset of
  * properties in an object.
  *
  *     assert.include([1,2,3], 2, 'array contains value');
  *     assert.include('foobar', 'foo', 'string contains substring');
  *     assert.include({ foo: 'bar', hello: 'universe' }, { foo: 'bar' }, 'object contains property');
  *
  * Strict equality (===) is used. When asserting the inclusion of a value in
  * an array, the array is searched for an element that's strictly equal to the
  * given value. When asserting a subset of properties in an object, the object
  * is searched for the given property keys, checking that each one is present
  * and strictly equal to the given property value. For instance:
  *
  *     var obj1 = {a: 1}
  *       , obj2 = {b: 2};
  *     assert.include([obj1, obj2], obj1);
  *     assert.include({foo: obj1, bar: obj2}, {foo: obj1});
  *     assert.include({foo: obj1, bar: obj2}, {foo: obj1, bar: obj2});
  *
  * @name include
  * @param {Array|String} haystack
  * @param {Mixed} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.include = function (exp, inc, msg) {
   new Assertion(exp, msg, assert.include, true).include(inc);
 };

 /**
  * ### .notInclude(haystack, needle, [message])
  *
  * Asserts that `haystack` does not include `needle`. Can be used to assert
  * the absence of a value in an array, a substring in a string, or a subset of
  * properties in an object.
  *
  *     assert.notInclude([1,2,3], 4, "array doesn't contain value");
  *     assert.notInclude('foobar', 'baz', "string doesn't contain substring");
  *     assert.notInclude({ foo: 'bar', hello: 'universe' }, { foo: 'baz' }, 'object doesn't contain property');
  *
  * Strict equality (===) is used. When asserting the absence of a value in an
  * array, the array is searched to confirm the absence of an element that's
  * strictly equal to the given value. When asserting a subset of properties in
  * an object, the object is searched to confirm that at least one of the given
  * property keys is either not present or not strictly equal to the given
  * property value. For instance:
  *
  *     var obj1 = {a: 1}
  *       , obj2 = {b: 2};
  *     assert.notInclude([obj1, obj2], {a: 1});
  *     assert.notInclude({foo: obj1, bar: obj2}, {foo: {a: 1}});
  *     assert.notInclude({foo: obj1, bar: obj2}, {foo: obj1, bar: {b: 2}});
  *
  * @name notInclude
  * @param {Array|String} haystack
  * @param {Mixed} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notInclude = function (exp, inc, msg) {
   new Assertion(exp, msg, assert.notInclude, true).not.include(inc);
 };

 /**
  * ### .deepInclude(haystack, needle, [message])
  *
  * Asserts that `haystack` includes `needle`. Can be used to assert the
  * inclusion of a value in an array or a subset of properties in an object.
  * Deep equality is used.
  *
  *     var obj1 = {a: 1}
  *       , obj2 = {b: 2};
  *     assert.deepInclude([obj1, obj2], {a: 1});
  *     assert.deepInclude({foo: obj1, bar: obj2}, {foo: {a: 1}});
  *     assert.deepInclude({foo: obj1, bar: obj2}, {foo: {a: 1}, bar: {b: 2}});
  *
  * @name deepInclude
  * @param {Array|String} haystack
  * @param {Mixed} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.deepInclude = function (exp, inc, msg) {
   new Assertion(exp, msg, assert.deepInclude, true).deep.include(inc);
 };

 /**
  * ### .notDeepInclude(haystack, needle, [message])
  *
  * Asserts that `haystack` does not include `needle`. Can be used to assert
  * the absence of a value in an array or a subset of properties in an object.
  * Deep equality is used.
  *
  *     var obj1 = {a: 1}
  *       , obj2 = {b: 2};
  *     assert.notDeepInclude([obj1, obj2], {a: 9});
  *     assert.notDeepInclude({foo: obj1, bar: obj2}, {foo: {a: 9}});
  *     assert.notDeepInclude({foo: obj1, bar: obj2}, {foo: {a: 1}, bar: {b: 9}});
  *
  * @name notDeepInclude
  * @param {Array|String} haystack
  * @param {Mixed} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notDeepInclude = function (exp, inc, msg) {
   new Assertion(exp, msg, assert.notDeepInclude, true).not.deep.include(inc);
 };

 /**
  * ### .nestedInclude(haystack, needle, [message])
  *
  * Asserts that 'haystack' includes 'needle'.
  * Can be used to assert the inclusion of a subset of properties in an
  * object.
  * Enables the use of dot- and bracket-notation for referencing nested
  * properties.
  * '[]' and '.' in property names can be escaped using double backslashes.
  *
  *     assert.nestedInclude({'.a': {'b': 'x'}}, {'\\.a.[b]': 'x'});
  *     assert.nestedInclude({'a': {'[b]': 'x'}}, {'a.\\[b\\]': 'x'});
  *
  * @name nestedInclude
  * @param {Object} haystack
  * @param {Object} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.nestedInclude = function (exp, inc, msg) {
   new Assertion(exp, msg, assert.nestedInclude, true).nested.include(inc);
 };

 /**
  * ### .notNestedInclude(haystack, needle, [message])
  *
  * Asserts that 'haystack' does not include 'needle'.
  * Can be used to assert the absence of a subset of properties in an
  * object.
  * Enables the use of dot- and bracket-notation for referencing nested
  * properties.
  * '[]' and '.' in property names can be escaped using double backslashes.
  *
  *     assert.notNestedInclude({'.a': {'b': 'x'}}, {'\\.a.b': 'y'});
  *     assert.notNestedInclude({'a': {'[b]': 'x'}}, {'a.\\[b\\]': 'y'});
  *
  * @name notNestedInclude
  * @param {Object} haystack
  * @param {Object} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notNestedInclude = function (exp, inc, msg) {
   new Assertion(exp, msg, assert.notNestedInclude, true)
     .not.nested.include(inc);
 };

 /**
  * ### .deepNestedInclude(haystack, needle, [message])
  *
  * Asserts that 'haystack' includes 'needle'.
  * Can be used to assert the inclusion of a subset of properties in an
  * object while checking for deep equality.
  * Enables the use of dot- and bracket-notation for referencing nested
  * properties.
  * '[]' and '.' in property names can be escaped using double backslashes.
  *
  *     assert.deepNestedInclude({a: {b: [{x: 1}]}}, {'a.b[0]': {x: 1}});
  *     assert.deepNestedInclude({'.a': {'[b]': {x: 1}}}, {'\\.a.\\[b\\]': {x: 1}});
  *
  * @name deepNestedInclude
  * @param {Object} haystack
  * @param {Object} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.deepNestedInclude = function(exp, inc, msg) {
   new Assertion(exp, msg, assert.deepNestedInclude, true)
     .deep.nested.include(inc);
 };

 /**
  * ### .notDeepNestedInclude(haystack, needle, [message])
  *
  * Asserts that 'haystack' does not include 'needle'.
  * Can be used to assert the absence of a subset of properties in an
  * object while checking for deep equality.
  * Enables the use of dot- and bracket-notation for referencing nested
  * properties.
  * '[]' and '.' in property names can be escaped using double backslashes.
  *
  *     assert.notDeepNestedInclude({a: {b: [{x: 1}]}}, {'a.b[0]': {y: 1}})
  *     assert.notDeepNestedInclude({'.a': {'[b]': {x: 1}}}, {'\\.a.\\[b\\]': {y: 2}});
  *
  * @name notDeepNestedInclude
  * @param {Object} haystack
  * @param {Object} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notDeepNestedInclude = function(exp, inc, msg) {
   new Assertion(exp, msg, assert.notDeepNestedInclude, true)
     .not.deep.nested.include(inc);
 };

 /**
  * ### .ownInclude(haystack, needle, [message])
  *
  * Asserts that 'haystack' includes 'needle'.
  * Can be used to assert the inclusion of a subset of properties in an
  * object while ignoring inherited properties.
  *
  *     assert.ownInclude({ a: 1 }, { a: 1 });
  *
  * @name ownInclude
  * @param {Object} haystack
  * @param {Object} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.ownInclude = function(exp, inc, msg) {
   new Assertion(exp, msg, assert.ownInclude, true).own.include(inc);
 };

 /**
  * ### .notOwnInclude(haystack, needle, [message])
  *
  * Asserts that 'haystack' includes 'needle'.
  * Can be used to assert the absence of a subset of properties in an
  * object while ignoring inherited properties.
  *
  *     Object.prototype.b = 2;
  *
  *     assert.notOwnInclude({ a: 1 }, { b: 2 });
  *
  * @name notOwnInclude
  * @param {Object} haystack
  * @param {Object} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notOwnInclude = function(exp, inc, msg) {
   new Assertion(exp, msg, assert.notOwnInclude, true).not.own.include(inc);
 };

 /**
  * ### .deepOwnInclude(haystack, needle, [message])
  *
  * Asserts that 'haystack' includes 'needle'.
  * Can be used to assert the inclusion of a subset of properties in an
  * object while ignoring inherited properties and checking for deep equality.
  *
  *      assert.deepOwnInclude({a: {b: 2}}, {a: {b: 2}});
  *
  * @name deepOwnInclude
  * @param {Object} haystack
  * @param {Object} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.deepOwnInclude = function(exp, inc, msg) {
   new Assertion(exp, msg, assert.deepOwnInclude, true)
     .deep.own.include(inc);
 };

  /**
  * ### .notDeepOwnInclude(haystack, needle, [message])
  *
  * Asserts that 'haystack' includes 'needle'.
  * Can be used to assert the absence of a subset of properties in an
  * object while ignoring inherited properties and checking for deep equality.
  *
  *      assert.notDeepOwnInclude({a: {b: 2}}, {a: {c: 3}});
  *
  * @name notDeepOwnInclude
  * @param {Object} haystack
  * @param {Object} needle
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notDeepOwnInclude = function(exp, inc, msg) {
   new Assertion(exp, msg, assert.notDeepOwnInclude, true)
     .not.deep.own.include(inc);
 };

 /**
  * ### .match(value, regexp, [message])
  *
  * Asserts that `value` matches the regular expression `regexp`.
  *
  *     assert.match('foobar', /^foo/, 'regexp matches');
  *
  * @name match
  * @param {Mixed} value
  * @param {RegExp} regexp
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.match = function (exp, re, msg) {
   new Assertion(exp, msg, assert.match, true).to.match(re);
 };

 /**
  * ### .notMatch(value, regexp, [message])
  *
  * Asserts that `value` does not match the regular expression `regexp`.
  *
  *     assert.notMatch('foobar', /^foo/, 'regexp does not match');
  *
  * @name notMatch
  * @param {Mixed} value
  * @param {RegExp} regexp
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notMatch = function (exp, re, msg) {
   new Assertion(exp, msg, assert.notMatch, true).to.not.match(re);
 };

 /**
  * ### .property(object, property, [message])
  *
  * Asserts that `object` has a direct or inherited property named by
  * `property`.
  *
  *     assert.property({ tea: { green: 'matcha' }}, 'tea');
  *     assert.property({ tea: { green: 'matcha' }}, 'toString');
  *
  * @name property
  * @param {Object} object
  * @param {String} property
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.property = function (obj, prop, msg) {
   new Assertion(obj, msg, assert.property, true).to.have.property(prop);
 };

 /**
  * ### .notProperty(object, property, [message])
  *
  * Asserts that `object` does _not_ have a direct or inherited property named
  * by `property`.
  *
  *     assert.notProperty({ tea: { green: 'matcha' }}, 'coffee');
  *
  * @name notProperty
  * @param {Object} object
  * @param {String} property
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notProperty = function (obj, prop, msg) {
   new Assertion(obj, msg, assert.notProperty, true)
     .to.not.have.property(prop);
 };

 /**
  * ### .propertyVal(object, property, value, [message])
  *
  * Asserts that `object` has a direct or inherited property named by
  * `property` with a value given by `value`. Uses a strict equality check
  * (===).
  *
  *     assert.propertyVal({ tea: 'is good' }, 'tea', 'is good');
  *
  * @name propertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.propertyVal = function (obj, prop, val, msg) {
   new Assertion(obj, msg, assert.propertyVal, true)
     .to.have.property(prop, val);
 };

 /**
  * ### .notPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` does _not_ have a direct or inherited property named
  * by `property` with value given by `value`. Uses a strict equality check
  * (===).
  *
  *     assert.notPropertyVal({ tea: 'is good' }, 'tea', 'is bad');
  *     assert.notPropertyVal({ tea: 'is good' }, 'coffee', 'is good');
  *
  * @name notPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notPropertyVal = function (obj, prop, val, msg) {
   new Assertion(obj, msg, assert.notPropertyVal, true)
     .to.not.have.property(prop, val);
 };

 /**
  * ### .deepPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` has a direct or inherited property named by
  * `property` with a value given by `value`. Uses a deep equality check.
  *
  *     assert.deepPropertyVal({ tea: { green: 'matcha' } }, 'tea', { green: 'matcha' });
  *
  * @name deepPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.deepPropertyVal = function (obj, prop, val, msg) {
   new Assertion(obj, msg, assert.deepPropertyVal, true)
     .to.have.deep.property(prop, val);
 };

 /**
  * ### .notDeepPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` does _not_ have a direct or inherited property named
  * by `property` with value given by `value`. Uses a deep equality check.
  *
  *     assert.notDeepPropertyVal({ tea: { green: 'matcha' } }, 'tea', { black: 'matcha' });
  *     assert.notDeepPropertyVal({ tea: { green: 'matcha' } }, 'tea', { green: 'oolong' });
  *     assert.notDeepPropertyVal({ tea: { green: 'matcha' } }, 'coffee', { green: 'matcha' });
  *
  * @name notDeepPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notDeepPropertyVal = function (obj, prop, val, msg) {
   new Assertion(obj, msg, assert.notDeepPropertyVal, true)
     .to.not.have.deep.property(prop, val);
 };

 /**
  * ### .ownProperty(object, property, [message])
  *
  * Asserts that `object` has a direct property named by `property`. Inherited
  * properties aren't checked.
  *
  *     assert.ownProperty({ tea: { green: 'matcha' }}, 'tea');
  *
  * @name ownProperty
  * @param {Object} object
  * @param {String} property
  * @param {String} message
  * @api public
  */

 assert.ownProperty = function (obj, prop, msg) {
   new Assertion(obj, msg, assert.ownProperty, true)
     .to.have.own.property(prop);
 };

 /**
  * ### .notOwnProperty(object, property, [message])
  *
  * Asserts that `object` does _not_ have a direct property named by
  * `property`. Inherited properties aren't checked.
  *
  *     assert.notOwnProperty({ tea: { green: 'matcha' }}, 'coffee');
  *     assert.notOwnProperty({}, 'toString');
  *
  * @name notOwnProperty
  * @param {Object} object
  * @param {String} property
  * @param {String} message
  * @api public
  */

 assert.notOwnProperty = function (obj, prop, msg) {
   new Assertion(obj, msg, assert.notOwnProperty, true)
     .to.not.have.own.property(prop);
 };

 /**
  * ### .ownPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` has a direct property named by `property` and a value
  * equal to the provided `value`. Uses a strict equality check (===).
  * Inherited properties aren't checked.
  *
  *     assert.ownPropertyVal({ coffee: 'is good'}, 'coffee', 'is good');
  *
  * @name ownPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @api public
  */

 assert.ownPropertyVal = function (obj, prop, value, msg) {
   new Assertion(obj, msg, assert.ownPropertyVal, true)
     .to.have.own.property(prop, value);
 };

 /**
  * ### .notOwnPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` does _not_ have a direct property named by `property`
  * with a value equal to the provided `value`. Uses a strict equality check
  * (===). Inherited properties aren't checked.
  *
  *     assert.notOwnPropertyVal({ tea: 'is better'}, 'tea', 'is worse');
  *     assert.notOwnPropertyVal({}, 'toString', Object.prototype.toString);
  *
  * @name notOwnPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @api public
  */

 assert.notOwnPropertyVal = function (obj, prop, value, msg) {
   new Assertion(obj, msg, assert.notOwnPropertyVal, true)
     .to.not.have.own.property(prop, value);
 };

 /**
  * ### .deepOwnPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` has a direct property named by `property` and a value
  * equal to the provided `value`. Uses a deep equality check. Inherited
  * properties aren't checked.
  *
  *     assert.deepOwnPropertyVal({ tea: { green: 'matcha' } }, 'tea', { green: 'matcha' });
  *
  * @name deepOwnPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @api public
  */

 assert.deepOwnPropertyVal = function (obj, prop, value, msg) {
   new Assertion(obj, msg, assert.deepOwnPropertyVal, true)
     .to.have.deep.own.property(prop, value);
 };

 /**
  * ### .notDeepOwnPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` does _not_ have a direct property named by `property`
  * with a value equal to the provided `value`. Uses a deep equality check.
  * Inherited properties aren't checked.
  *
  *     assert.notDeepOwnPropertyVal({ tea: { green: 'matcha' } }, 'tea', { black: 'matcha' });
  *     assert.notDeepOwnPropertyVal({ tea: { green: 'matcha' } }, 'tea', { green: 'oolong' });
  *     assert.notDeepOwnPropertyVal({ tea: { green: 'matcha' } }, 'coffee', { green: 'matcha' });
  *     assert.notDeepOwnPropertyVal({}, 'toString', Object.prototype.toString);
  *
  * @name notDeepOwnPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @api public
  */

 assert.notDeepOwnPropertyVal = function (obj, prop, value, msg) {
   new Assertion(obj, msg, assert.notDeepOwnPropertyVal, true)
     .to.not.have.deep.own.property(prop, value);
 };

 /**
  * ### .nestedProperty(object, property, [message])
  *
  * Asserts that `object` has a direct or inherited property named by
  * `property`, which can be a string using dot- and bracket-notation for
  * nested reference.
  *
  *     assert.nestedProperty({ tea: { green: 'matcha' }}, 'tea.green');
  *
  * @name nestedProperty
  * @param {Object} object
  * @param {String} property
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.nestedProperty = function (obj, prop, msg) {
   new Assertion(obj, msg, assert.nestedProperty, true)
     .to.have.nested.property(prop);
 };

 /**
  * ### .notNestedProperty(object, property, [message])
  *
  * Asserts that `object` does _not_ have a property named by `property`, which
  * can be a string using dot- and bracket-notation for nested reference. The
  * property cannot exist on the object nor anywhere in its prototype chain.
  *
  *     assert.notNestedProperty({ tea: { green: 'matcha' }}, 'tea.oolong');
  *
  * @name notNestedProperty
  * @param {Object} object
  * @param {String} property
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notNestedProperty = function (obj, prop, msg) {
   new Assertion(obj, msg, assert.notNestedProperty, true)
     .to.not.have.nested.property(prop);
 };

 /**
  * ### .nestedPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` has a property named by `property` with value given
  * by `value`. `property` can use dot- and bracket-notation for nested
  * reference. Uses a strict equality check (===).
  *
  *     assert.nestedPropertyVal({ tea: { green: 'matcha' }}, 'tea.green', 'matcha');
  *
  * @name nestedPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.nestedPropertyVal = function (obj, prop, val, msg) {
   new Assertion(obj, msg, assert.nestedPropertyVal, true)
     .to.have.nested.property(prop, val);
 };

 /**
  * ### .notNestedPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` does _not_ have a property named by `property` with
  * value given by `value`. `property` can use dot- and bracket-notation for
  * nested reference. Uses a strict equality check (===).
  *
  *     assert.notNestedPropertyVal({ tea: { green: 'matcha' }}, 'tea.green', 'konacha');
  *     assert.notNestedPropertyVal({ tea: { green: 'matcha' }}, 'coffee.green', 'matcha');
  *
  * @name notNestedPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notNestedPropertyVal = function (obj, prop, val, msg) {
   new Assertion(obj, msg, assert.notNestedPropertyVal, true)
     .to.not.have.nested.property(prop, val);
 };

 /**
  * ### .deepNestedPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` has a property named by `property` with a value given
  * by `value`. `property` can use dot- and bracket-notation for nested
  * reference. Uses a deep equality check.
  *
  *     assert.deepNestedPropertyVal({ tea: { green: { matcha: 'yum' } } }, 'tea.green', { matcha: 'yum' });
  *
  * @name deepNestedPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.deepNestedPropertyVal = function (obj, prop, val, msg) {
   new Assertion(obj, msg, assert.deepNestedPropertyVal, true)
     .to.have.deep.nested.property(prop, val);
 };

 /**
  * ### .notDeepNestedPropertyVal(object, property, value, [message])
  *
  * Asserts that `object` does _not_ have a property named by `property` with
  * value given by `value`. `property` can use dot- and bracket-notation for
  * nested reference. Uses a deep equality check.
  *
  *     assert.notDeepNestedPropertyVal({ tea: { green: { matcha: 'yum' } } }, 'tea.green', { oolong: 'yum' });
  *     assert.notDeepNestedPropertyVal({ tea: { green: { matcha: 'yum' } } }, 'tea.green', { matcha: 'yuck' });
  *     assert.notDeepNestedPropertyVal({ tea: { green: { matcha: 'yum' } } }, 'tea.black', { matcha: 'yum' });
  *
  * @name notDeepNestedPropertyVal
  * @param {Object} object
  * @param {String} property
  * @param {Mixed} value
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notDeepNestedPropertyVal = function (obj, prop, val, msg) {
   new Assertion(obj, msg, assert.notDeepNestedPropertyVal, true)
     .to.not.have.deep.nested.property(prop, val);
 }

 /**
  * ### .lengthOf(object, length, [message])
  *
  * Asserts that `object` has a `length` or `size` with the expected value.
  *
  *     assert.lengthOf([1,2,3], 3, 'array has length of 3');
  *     assert.lengthOf('foobar', 6, 'string has length of 6');
  *     assert.lengthOf(new Set([1,2,3]), 3, 'set has size of 3');
  *     assert.lengthOf(new Map([['a',1],['b',2],['c',3]]), 3, 'map has size of 3');
  *
  * @name lengthOf
  * @param {Mixed} object
  * @param {Number} length
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.lengthOf = function (exp, len, msg) {
   new Assertion(exp, msg, assert.lengthOf, true).to.have.lengthOf(len);
 };

 /**
  * ### .hasAnyKeys(object, [keys], [message])
  *
  * Asserts that `object` has at least one of the `keys` provided.
  * You can also provide a single object instead of a `keys` array and its keys
  * will be used as the expected set of keys.
  *
  *     assert.hasAnyKeys({foo: 1, bar: 2, baz: 3}, ['foo', 'iDontExist', 'baz']);
  *     assert.hasAnyKeys({foo: 1, bar: 2, baz: 3}, {foo: 30, iDontExist: 99, baz: 1337});
  *     assert.hasAnyKeys(new Map([[{foo: 1}, 'bar'], ['key', 'value']]), [{foo: 1}, 'key']);
  *     assert.hasAnyKeys(new Set([{foo: 'bar'}, 'anotherKey']), [{foo: 'bar'}, 'anotherKey']);
  *
  * @name hasAnyKeys
  * @param {Mixed} object
  * @param {Array|Object} keys
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.hasAnyKeys = function (obj, keys, msg) {
   new Assertion(obj, msg, assert.hasAnyKeys, true).to.have.any.keys(keys);
 }

 /**
  * ### .hasAllKeys(object, [keys], [message])
  *
  * Asserts that `object` has all and only all of the `keys` provided.
  * You can also provide a single object instead of a `keys` array and its keys
  * will be used as the expected set of keys.
  *
  *     assert.hasAllKeys({foo: 1, bar: 2, baz: 3}, ['foo', 'bar', 'baz']);
  *     assert.hasAllKeys({foo: 1, bar: 2, baz: 3}, {foo: 30, bar: 99, baz: 1337]);
  *     assert.hasAllKeys(new Map([[{foo: 1}, 'bar'], ['key', 'value']]), [{foo: 1}, 'key']);
  *     assert.hasAllKeys(new Set([{foo: 'bar'}, 'anotherKey'], [{foo: 'bar'}, 'anotherKey']);
  *
  * @name hasAllKeys
  * @param {Mixed} object
  * @param {String[]} keys
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.hasAllKeys = function (obj, keys, msg) {
   new Assertion(obj, msg, assert.hasAllKeys, true).to.have.all.keys(keys);
 }

 /**
  * ### .containsAllKeys(object, [keys], [message])
  *
  * Asserts that `object` has all of the `keys` provided but may have more keys not listed.
  * You can also provide a single object instead of a `keys` array and its keys
  * will be used as the expected set of keys.
  *
  *     assert.containsAllKeys({foo: 1, bar: 2, baz: 3}, ['foo', 'baz']);
  *     assert.containsAllKeys({foo: 1, bar: 2, baz: 3}, ['foo', 'bar', 'baz']);
  *     assert.containsAllKeys({foo: 1, bar: 2, baz: 3}, {foo: 30, baz: 1337});
  *     assert.containsAllKeys({foo: 1, bar: 2, baz: 3}, {foo: 30, bar: 99, baz: 1337});
  *     assert.containsAllKeys(new Map([[{foo: 1}, 'bar'], ['key', 'value']]), [{foo: 1}]);
  *     assert.containsAllKeys(new Map([[{foo: 1}, 'bar'], ['key', 'value']]), [{foo: 1}, 'key']);
  *     assert.containsAllKeys(new Set([{foo: 'bar'}, 'anotherKey'], [{foo: 'bar'}]);
  *     assert.containsAllKeys(new Set([{foo: 'bar'}, 'anotherKey'], [{foo: 'bar'}, 'anotherKey']);
  *
  * @name containsAllKeys
  * @param {Mixed} object
  * @param {String[]} keys
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.containsAllKeys = function (obj, keys, msg) {
   new Assertion(obj, msg, assert.containsAllKeys, true)
     .to.contain.all.keys(keys);
 }

 /**
  * ### .doesNotHaveAnyKeys(object, [keys], [message])
  *
  * Asserts that `object` has none of the `keys` provided.
  * You can also provide a single object instead of a `keys` array and its keys
  * will be used as the expected set of keys.
  *
  *     assert.doesNotHaveAnyKeys({foo: 1, bar: 2, baz: 3}, ['one', 'two', 'example']);
  *     assert.doesNotHaveAnyKeys({foo: 1, bar: 2, baz: 3}, {one: 1, two: 2, example: 'foo'});
  *     assert.doesNotHaveAnyKeys(new Map([[{foo: 1}, 'bar'], ['key', 'value']]), [{one: 'two'}, 'example']);
  *     assert.doesNotHaveAnyKeys(new Set([{foo: 'bar'}, 'anotherKey'], [{one: 'two'}, 'example']);
  *
  * @name doesNotHaveAnyKeys
  * @param {Mixed} object
  * @param {String[]} keys
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.doesNotHaveAnyKeys = function (obj, keys, msg) {
   new Assertion(obj, msg, assert.doesNotHaveAnyKeys, true)
     .to.not.have.any.keys(keys);
 }

 /**
  * ### .doesNotHaveAllKeys(object, [keys], [message])
  *
  * Asserts that `object` does not have at least one of the `keys` provided.
  * You can also provide a single object instead of a `keys` array and its keys
  * will be used as the expected set of keys.
  *
  *     assert.doesNotHaveAllKeys({foo: 1, bar: 2, baz: 3}, ['one', 'two', 'example']);
  *     assert.doesNotHaveAllKeys({foo: 1, bar: 2, baz: 3}, {one: 1, two: 2, example: 'foo'});
  *     assert.doesNotHaveAllKeys(new Map([[{foo: 1}, 'bar'], ['key', 'value']]), [{one: 'two'}, 'example']);
  *     assert.doesNotHaveAllKeys(new Set([{foo: 'bar'}, 'anotherKey'], [{one: 'two'}, 'example']);
  *
  * @name doesNotHaveAllKeys
  * @param {Mixed} object
  * @param {String[]} keys
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.doesNotHaveAllKeys = function (obj, keys, msg) {
   new Assertion(obj, msg, assert.doesNotHaveAllKeys, true)
     .to.not.have.all.keys(keys);
 }

 /**
  * ### .hasAnyDeepKeys(object, [keys], [message])
  *
  * Asserts that `object` has at least one of the `keys` provided.
  * Since Sets and Maps can have objects as keys you can use this assertion to perform
  * a deep comparison.
  * You can also provide a single object instead of a `keys` array and its keys
  * will be used as the expected set of keys.
  *
  *     assert.hasAnyDeepKeys(new Map([[{one: 'one'}, 'valueOne'], [1, 2]]), {one: 'one'});
  *     assert.hasAnyDeepKeys(new Map([[{one: 'one'}, 'valueOne'], [1, 2]]), [{one: 'one'}, {two: 'two'}]);
  *     assert.hasAnyDeepKeys(new Map([[{one: 'one'}, 'valueOne'], [{two: 'two'}, 'valueTwo']]), [{one: 'one'}, {two: 'two'}]);
  *     assert.hasAnyDeepKeys(new Set([{one: 'one'}, {two: 'two'}]), {one: 'one'});
  *     assert.hasAnyDeepKeys(new Set([{one: 'one'}, {two: 'two'}]), [{one: 'one'}, {three: 'three'}]);
  *     assert.hasAnyDeepKeys(new Set([{one: 'one'}, {two: 'two'}]), [{one: 'one'}, {two: 'two'}]);
  *
  * @name doesNotHaveAllKeys
  * @param {Mixed} object
  * @param {Array|Object} keys
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.hasAnyDeepKeys = function (obj, keys, msg) {
   new Assertion(obj, msg, assert.hasAnyDeepKeys, true)
     .to.have.any.deep.keys(keys);
 }

/**
  * ### .hasAllDeepKeys(object, [keys], [message])
  *
  * Asserts that `object` has all and only all of the `keys` provided.
  * Since Sets and Maps can have objects as keys you can use this assertion to perform
  * a deep comparison.
  * You can also provide a single object instead of a `keys` array and its keys
  * will be used as the expected set of keys.
  *
  *     assert.hasAllDeepKeys(new Map([[{one: 'one'}, 'valueOne']]), {one: 'one'});
  *     assert.hasAllDeepKeys(new Map([[{one: 'one'}, 'valueOne'], [{two: 'two'}, 'valueTwo']]), [{one: 'one'}, {two: 'two'}]);
  *     assert.hasAllDeepKeys(new Set([{one: 'one'}]), {one: 'one'});
  *     assert.hasAllDeepKeys(new Set([{one: 'one'}, {two: 'two'}]), [{one: 'one'}, {two: 'two'}]);
  *
  * @name hasAllDeepKeys
  * @param {Mixed} object
  * @param {Array|Object} keys
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.hasAllDeepKeys = function (obj, keys, msg) {
   new Assertion(obj, msg, assert.hasAllDeepKeys, true)
     .to.have.all.deep.keys(keys);
 }

/**
  * ### .containsAllDeepKeys(object, [keys], [message])
  *
  * Asserts that `object` contains all of the `keys` provided.
  * Since Sets and Maps can have objects as keys you can use this assertion to perform
  * a deep comparison.
  * You can also provide a single object instead of a `keys` array and its keys
  * will be used as the expected set of keys.
  *
  *     assert.containsAllDeepKeys(new Map([[{one: 'one'}, 'valueOne'], [1, 2]]), {one: 'one'});
  *     assert.containsAllDeepKeys(new Map([[{one: 'one'}, 'valueOne'], [{two: 'two'}, 'valueTwo']]), [{one: 'one'}, {two: 'two'}]);
  *     assert.containsAllDeepKeys(new Set([{one: 'one'}, {two: 'two'}]), {one: 'one'});
  *     assert.containsAllDeepKeys(new Set([{one: 'one'}, {two: 'two'}]), [{one: 'one'}, {two: 'two'}]);
  *
  * @name containsAllDeepKeys
  * @param {Mixed} object
  * @param {Array|Object} keys
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.containsAllDeepKeys = function (obj, keys, msg) {
   new Assertion(obj, msg, assert.containsAllDeepKeys, true)
     .to.contain.all.deep.keys(keys);
 }

/**
  * ### .doesNotHaveAnyDeepKeys(object, [keys], [message])
  *
  * Asserts that `object` has none of the `keys` provided.
  * Since Sets and Maps can have objects as keys you can use this assertion to perform
  * a deep comparison.
  * You can also provide a single object instead of a `keys` array and its keys
  * will be used as the expected set of keys.
  *
  *     assert.doesNotHaveAnyDeepKeys(new Map([[{one: 'one'}, 'valueOne'], [1, 2]]), {thisDoesNot: 'exist'});
  *     assert.doesNotHaveAnyDeepKeys(new Map([[{one: 'one'}, 'valueOne'], [{two: 'two'}, 'valueTwo']]), [{twenty: 'twenty'}, {fifty: 'fifty'}]);
  *     assert.doesNotHaveAnyDeepKeys(new Set([{one: 'one'}, {two: 'two'}]), {twenty: 'twenty'});
  *     assert.doesNotHaveAnyDeepKeys(new Set([{one: 'one'}, {two: 'two'}]), [{twenty: 'twenty'}, {fifty: 'fifty'}]);
  *
  * @name doesNotHaveAnyDeepKeys
  * @param {Mixed} object
  * @param {Array|Object} keys
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.doesNotHaveAnyDeepKeys = function (obj, keys, msg) {
   new Assertion(obj, msg, assert.doesNotHaveAnyDeepKeys, true)
     .to.not.have.any.deep.keys(keys);
 }

/**
  * ### .doesNotHaveAllDeepKeys(object, [keys], [message])
  *
  * Asserts that `object` does not have at least one of the `keys` provided.
  * Since Sets and Maps can have objects as keys you can use this assertion to perform
  * a deep comparison.
  * You can also provide a single object instead of a `keys` array and its keys
  * will be used as the expected set of keys.
  *
  *     assert.doesNotHaveAllDeepKeys(new Map([[{one: 'one'}, 'valueOne'], [1, 2]]), {thisDoesNot: 'exist'});
  *     assert.doesNotHaveAllDeepKeys(new Map([[{one: 'one'}, 'valueOne'], [{two: 'two'}, 'valueTwo']]), [{twenty: 'twenty'}, {one: 'one'}]);
  *     assert.doesNotHaveAllDeepKeys(new Set([{one: 'one'}, {two: 'two'}]), {twenty: 'twenty'});
  *     assert.doesNotHaveAllDeepKeys(new Set([{one: 'one'}, {two: 'two'}]), [{one: 'one'}, {fifty: 'fifty'}]);
  *
  * @name doesNotHaveAllDeepKeys
  * @param {Mixed} object
  * @param {Array|Object} keys
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.doesNotHaveAllDeepKeys = function (obj, keys, msg) {
   new Assertion(obj, msg, assert.doesNotHaveAllDeepKeys, true)
     .to.not.have.all.deep.keys(keys);
 }

/**
  * ### .throws(fn, [errorLike/string/regexp], [string/regexp], [message])
  *
  * If `errorLike` is an `Error` constructor, asserts that `fn` will throw an error that is an
  * instance of `errorLike`.
  * If `errorLike` is an `Error` instance, asserts that the error thrown is the same
  * instance as `errorLike`.
  * If `errMsgMatcher` is provided, it also asserts that the error thrown will have a
  * message matching `errMsgMatcher`.
  *
  *     assert.throws(fn, 'Error thrown must have this msg');
  *     assert.throws(fn, /Error thrown must have a msg that matches this/);
  *     assert.throws(fn, ReferenceError);
  *     assert.throws(fn, errorInstance);
  *     assert.throws(fn, ReferenceError, 'Error thrown must be a ReferenceError and have this msg');
  *     assert.throws(fn, errorInstance, 'Error thrown must be the same errorInstance and have this msg');
  *     assert.throws(fn, ReferenceError, /Error thrown must be a ReferenceError and match this/);
  *     assert.throws(fn, errorInstance, /Error thrown must be the same errorInstance and match this/);
  *
  * @name throws
  * @alias throw
  * @alias Throw
  * @param {Function} fn
  * @param {ErrorConstructor|Error} errorLike
  * @param {RegExp|String} errMsgMatcher
  * @param {String} message
  * @see https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Error#Error_types
  * @namespace Assert
  * @api public
  */

 assert.throws = function (fn, errorLike, errMsgMatcher, msg) {
   if ('string' === typeof errorLike || errorLike instanceof RegExp) {
     errMsgMatcher = errorLike;
     errorLike = null;
   }

   var assertErr = new Assertion(fn, msg, assert.throws, true)
     .to.throw(errorLike, errMsgMatcher);
   return flag(assertErr, 'object');
 };

 /**
  * ### .doesNotThrow(fn, [errorLike/string/regexp], [string/regexp], [message])
  *
  * If `errorLike` is an `Error` constructor, asserts that `fn` will _not_ throw an error that is an
  * instance of `errorLike`.
  * If `errorLike` is an `Error` instance, asserts that the error thrown is _not_ the same
  * instance as `errorLike`.
  * If `errMsgMatcher` is provided, it also asserts that the error thrown will _not_ have a
  * message matching `errMsgMatcher`.
  *
  *     assert.doesNotThrow(fn, 'Any Error thrown must not have this message');
  *     assert.doesNotThrow(fn, /Any Error thrown must not match this/);
  *     assert.doesNotThrow(fn, Error);
  *     assert.doesNotThrow(fn, errorInstance);
  *     assert.doesNotThrow(fn, Error, 'Error must not have this message');
  *     assert.doesNotThrow(fn, errorInstance, 'Error must not have this message');
  *     assert.doesNotThrow(fn, Error, /Error must not match this/);
  *     assert.doesNotThrow(fn, errorInstance, /Error must not match this/);
  *
  * @name doesNotThrow
  * @param {Function} fn
  * @param {ErrorConstructor} errorLike
  * @param {RegExp|String} errMsgMatcher
  * @param {String} message
  * @see https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Error#Error_types
  * @namespace Assert
  * @api public
  */

 assert.doesNotThrow = function (fn, errorLike, errMsgMatcher, msg) {
   if ('string' === typeof errorLike || errorLike instanceof RegExp) {
     errMsgMatcher = errorLike;
     errorLike = null;
   }

   new Assertion(fn, msg, assert.doesNotThrow, true)
     .to.not.throw(errorLike, errMsgMatcher);
 };

 /**
  * ### .operator(val1, operator, val2, [message])
  *
  * Compares two values using `operator`.
  *
  *     assert.operator(1, '<', 2, 'everything is ok');
  *     assert.operator(1, '>', 2, 'this will fail');
  *
  * @name operator
  * @param {Mixed} val1
  * @param {String} operator
  * @param {Mixed} val2
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.operator = function (val, operator, val2, msg) {
   var ok;
   switch(operator) {
     case '==':
       ok = val == val2;
       break;
     case '===':
       ok = val === val2;
       break;
     case '>':
       ok = val > val2;
       break;
     case '>=':
       ok = val >= val2;
       break;
     case '<':
       ok = val < val2;
       break;
     case '<=':
       ok = val <= val2;
       break;
     case '!=':
       ok = val != val2;
       break;
     case '!==':
       ok = val !== val2;
       break;
     default:
       msg = msg ? msg + ': ' : msg;
       throw new chai.AssertionError(
         msg + 'Invalid operator "' + operator + '"',
         undefined,
         assert.operator
       );
   }
   var test = new Assertion(ok, msg, assert.operator, true);
   test.assert(
       true === flag(test, 'object')
     , 'expected ' + util.inspect(val) + ' to be ' + operator + ' ' + util.inspect(val2)
     , 'expected ' + util.inspect(val) + ' to not be ' + operator + ' ' + util.inspect(val2) );
 };

 /**
  * ### .closeTo(actual, expected, delta, [message])
  *
  * Asserts that the target is equal `expected`, to within a +/- `delta` range.
  *
  *     assert.closeTo(1.5, 1, 0.5, 'numbers are close');
  *
  * @name closeTo
  * @param {Number} actual
  * @param {Number} expected
  * @param {Number} delta
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.closeTo = function (act, exp, delta, msg) {
   new Assertion(act, msg, assert.closeTo, true).to.be.closeTo(exp, delta);
 };

 /**
  * ### .approximately(actual, expected, delta, [message])
  *
  * Asserts that the target is equal `expected`, to within a +/- `delta` range.
  *
  *     assert.approximately(1.5, 1, 0.5, 'numbers are close');
  *
  * @name approximately
  * @param {Number} actual
  * @param {Number} expected
  * @param {Number} delta
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.approximately = function (act, exp, delta, msg) {
   new Assertion(act, msg, assert.approximately, true)
     .to.be.approximately(exp, delta);
 };

 /**
  * ### .sameMembers(set1, set2, [message])
  *
  * Asserts that `set1` and `set2` have the same members in any order. Uses a
  * strict equality check (===).
  *
  *     assert.sameMembers([ 1, 2, 3 ], [ 2, 1, 3 ], 'same members');
  *
  * @name sameMembers
  * @param {Array} set1
  * @param {Array} set2
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.sameMembers = function (set1, set2, msg) {
   new Assertion(set1, msg, assert.sameMembers, true)
     .to.have.same.members(set2);
 }

 /**
  * ### .notSameMembers(set1, set2, [message])
  *
  * Asserts that `set1` and `set2` don't have the same members in any order.
  * Uses a strict equality check (===).
  *
  *     assert.notSameMembers([ 1, 2, 3 ], [ 5, 1, 3 ], 'not same members');
  *
  * @name notSameMembers
  * @param {Array} set1
  * @param {Array} set2
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notSameMembers = function (set1, set2, msg) {
   new Assertion(set1, msg, assert.notSameMembers, true)
     .to.not.have.same.members(set2);
 }

 /**
  * ### .sameDeepMembers(set1, set2, [message])
  *
  * Asserts that `set1` and `set2` have the same members in any order. Uses a
  * deep equality check.
  *
  *     assert.sameDeepMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [{ b: 2 }, { a: 1 }, { c: 3 }], 'same deep members');
  *
  * @name sameDeepMembers
  * @param {Array} set1
  * @param {Array} set2
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.sameDeepMembers = function (set1, set2, msg) {
   new Assertion(set1, msg, assert.sameDeepMembers, true)
     .to.have.same.deep.members(set2);
 }

 /**
  * ### .notSameDeepMembers(set1, set2, [message])
  *
  * Asserts that `set1` and `set2` don't have the same members in any order.
  * Uses a deep equality check.
  *
  *     assert.notSameDeepMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [{ b: 2 }, { a: 1 }, { f: 5 }], 'not same deep members');
  *
  * @name notSameDeepMembers
  * @param {Array} set1
  * @param {Array} set2
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notSameDeepMembers = function (set1, set2, msg) {
   new Assertion(set1, msg, assert.notSameDeepMembers, true)
     .to.not.have.same.deep.members(set2);
 }

 /**
  * ### .sameOrderedMembers(set1, set2, [message])
  *
  * Asserts that `set1` and `set2` have the same members in the same order.
  * Uses a strict equality check (===).
  *
  *     assert.sameOrderedMembers([ 1, 2, 3 ], [ 1, 2, 3 ], 'same ordered members');
  *
  * @name sameOrderedMembers
  * @param {Array} set1
  * @param {Array} set2
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.sameOrderedMembers = function (set1, set2, msg) {
   new Assertion(set1, msg, assert.sameOrderedMembers, true)
     .to.have.same.ordered.members(set2);
 }

 /**
  * ### .notSameOrderedMembers(set1, set2, [message])
  *
  * Asserts that `set1` and `set2` don't have the same members in the same
  * order. Uses a strict equality check (===).
  *
  *     assert.notSameOrderedMembers([ 1, 2, 3 ], [ 2, 1, 3 ], 'not same ordered members');
  *
  * @name notSameOrderedMembers
  * @param {Array} set1
  * @param {Array} set2
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notSameOrderedMembers = function (set1, set2, msg) {
   new Assertion(set1, msg, assert.notSameOrderedMembers, true)
     .to.not.have.same.ordered.members(set2);
 }

 /**
  * ### .sameDeepOrderedMembers(set1, set2, [message])
  *
  * Asserts that `set1` and `set2` have the same members in the same order.
  * Uses a deep equality check.
  *
  * assert.sameDeepOrderedMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [ { a: 1 }, { b: 2 }, { c: 3 } ], 'same deep ordered members');
  *
  * @name sameDeepOrderedMembers
  * @param {Array} set1
  * @param {Array} set2
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.sameDeepOrderedMembers = function (set1, set2, msg) {
   new Assertion(set1, msg, assert.sameDeepOrderedMembers, true)
     .to.have.same.deep.ordered.members(set2);
 }

 /**
  * ### .notSameDeepOrderedMembers(set1, set2, [message])
  *
  * Asserts that `set1` and `set2` don't have the same members in the same
  * order. Uses a deep equality check.
  *
  * assert.notSameDeepOrderedMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [ { a: 1 }, { b: 2 }, { z: 5 } ], 'not same deep ordered members');
  * assert.notSameDeepOrderedMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [ { b: 2 }, { a: 1 }, { c: 3 } ], 'not same deep ordered members');
  *
  * @name notSameDeepOrderedMembers
  * @param {Array} set1
  * @param {Array} set2
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notSameDeepOrderedMembers = function (set1, set2, msg) {
   new Assertion(set1, msg, assert.notSameDeepOrderedMembers, true)
     .to.not.have.same.deep.ordered.members(set2);
 }

 /**
  * ### .includeMembers(superset, subset, [message])
  *
  * Asserts that `subset` is included in `superset` in any order. Uses a
  * strict equality check (===). Duplicates are ignored.
  *
  *     assert.includeMembers([ 1, 2, 3 ], [ 2, 1, 2 ], 'include members');
  *
  * @name includeMembers
  * @param {Array} superset
  * @param {Array} subset
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.includeMembers = function (superset, subset, msg) {
   new Assertion(superset, msg, assert.includeMembers, true)
     .to.include.members(subset);
 }

 /**
  * ### .notIncludeMembers(superset, subset, [message])
  *
  * Asserts that `subset` isn't included in `superset` in any order. Uses a
  * strict equality check (===). Duplicates are ignored.
  *
  *     assert.notIncludeMembers([ 1, 2, 3 ], [ 5, 1 ], 'not include members');
  *
  * @name notIncludeMembers
  * @param {Array} superset
  * @param {Array} subset
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notIncludeMembers = function (superset, subset, msg) {
   new Assertion(superset, msg, assert.notIncludeMembers, true)
     .to.not.include.members(subset);
 }

 /**
  * ### .includeDeepMembers(superset, subset, [message])
  *
  * Asserts that `subset` is included in `superset` in any order. Uses a deep
  * equality check. Duplicates are ignored.
  *
  *     assert.includeDeepMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [ { b: 2 }, { a: 1 }, { b: 2 } ], 'include deep members');
  *
  * @name includeDeepMembers
  * @param {Array} superset
  * @param {Array} subset
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.includeDeepMembers = function (superset, subset, msg) {
   new Assertion(superset, msg, assert.includeDeepMembers, true)
     .to.include.deep.members(subset);
 }

 /**
  * ### .notIncludeDeepMembers(superset, subset, [message])
  *
  * Asserts that `subset` isn't included in `superset` in any order. Uses a
  * deep equality check. Duplicates are ignored.
  *
  *     assert.notIncludeDeepMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [ { b: 2 }, { f: 5 } ], 'not include deep members');
  *
  * @name notIncludeDeepMembers
  * @param {Array} superset
  * @param {Array} subset
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notIncludeDeepMembers = function (superset, subset, msg) {
   new Assertion(superset, msg, assert.notIncludeDeepMembers, true)
     .to.not.include.deep.members(subset);
 }

 /**
  * ### .includeOrderedMembers(superset, subset, [message])
  *
  * Asserts that `subset` is included in `superset` in the same order
  * beginning with the first element in `superset`. Uses a strict equality
  * check (===).
  *
  *     assert.includeOrderedMembers([ 1, 2, 3 ], [ 1, 2 ], 'include ordered members');
  *
  * @name includeOrderedMembers
  * @param {Array} superset
  * @param {Array} subset
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.includeOrderedMembers = function (superset, subset, msg) {
   new Assertion(superset, msg, assert.includeOrderedMembers, true)
     .to.include.ordered.members(subset);
 }

 /**
  * ### .notIncludeOrderedMembers(superset, subset, [message])
  *
  * Asserts that `subset` isn't included in `superset` in the same order
  * beginning with the first element in `superset`. Uses a strict equality
  * check (===).
  *
  *     assert.notIncludeOrderedMembers([ 1, 2, 3 ], [ 2, 1 ], 'not include ordered members');
  *     assert.notIncludeOrderedMembers([ 1, 2, 3 ], [ 2, 3 ], 'not include ordered members');
  *
  * @name notIncludeOrderedMembers
  * @param {Array} superset
  * @param {Array} subset
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notIncludeOrderedMembers = function (superset, subset, msg) {
   new Assertion(superset, msg, assert.notIncludeOrderedMembers, true)
     .to.not.include.ordered.members(subset);
 }

 /**
  * ### .includeDeepOrderedMembers(superset, subset, [message])
  *
  * Asserts that `subset` is included in `superset` in the same order
  * beginning with the first element in `superset`. Uses a deep equality
  * check.
  *
  *     assert.includeDeepOrderedMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [ { a: 1 }, { b: 2 } ], 'include deep ordered members');
  *
  * @name includeDeepOrderedMembers
  * @param {Array} superset
  * @param {Array} subset
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.includeDeepOrderedMembers = function (superset, subset, msg) {
   new Assertion(superset, msg, assert.includeDeepOrderedMembers, true)
     .to.include.deep.ordered.members(subset);
 }

 /**
  * ### .notIncludeDeepOrderedMembers(superset, subset, [message])
  *
  * Asserts that `subset` isn't included in `superset` in the same order
  * beginning with the first element in `superset`. Uses a deep equality
  * check.
  *
  *     assert.notIncludeDeepOrderedMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [ { a: 1 }, { f: 5 } ], 'not include deep ordered members');
  *     assert.notIncludeDeepOrderedMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [ { b: 2 }, { a: 1 } ], 'not include deep ordered members');
  *     assert.notIncludeDeepOrderedMembers([ { a: 1 }, { b: 2 }, { c: 3 } ], [ { b: 2 }, { c: 3 } ], 'not include deep ordered members');
  *
  * @name notIncludeDeepOrderedMembers
  * @param {Array} superset
  * @param {Array} subset
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.notIncludeDeepOrderedMembers = function (superset, subset, msg) {
   new Assertion(superset, msg, assert.notIncludeDeepOrderedMembers, true)
     .to.not.include.deep.ordered.members(subset);
 }

 /**
  * ### .oneOf(inList, list, [message])
  *
  * Asserts that non-object, non-array value `inList` appears in the flat array `list`.
  *
  *     assert.oneOf(1, [ 2, 1 ], 'Not found in list');
  *
  * @name oneOf
  * @param {*} inList
  * @param {Array<*>} list
  * @param {String} message
  * @namespace Assert
  * @api public
  */

 assert.oneOf = function (inList, list, msg) {
   new Assertion(inList, msg, assert.oneOf, true).to.be.oneOf(list);
 }

 /**
  * ### .changes(function, object, property, [message])
  *
  * Asserts that a function changes the value of a property.
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val = 22 };
  *     assert.changes(fn, obj, 'val');
  *
  * @name changes
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.changes = function (fn, obj, prop, msg) {
   if (arguments.length === 3 && typeof obj === 'function') {
     msg = prop;
     prop = null;
   }

   new Assertion(fn, msg, assert.changes, true).to.change(obj, prop);
 }

  /**
  * ### .changesBy(function, object, property, delta, [message])
  *
  * Asserts that a function changes the value of a property by an amount (delta).
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val += 2 };
  *     assert.changesBy(fn, obj, 'val', 2);
  *
  * @name changesBy
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {Number} change amount (delta)
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.changesBy = function (fn, obj, prop, delta, msg) {
   if (arguments.length === 4 && typeof obj === 'function') {
     var tmpMsg = delta;
     delta = prop;
     msg = tmpMsg;
   } else if (arguments.length === 3) {
     delta = prop;
     prop = null;
   }

   new Assertion(fn, msg, assert.changesBy, true)
     .to.change(obj, prop).by(delta);
 }

  /**
  * ### .doesNotChange(function, object, property, [message])
  *
  * Asserts that a function does not change the value of a property.
  *
  *     var obj = { val: 10 };
  *     var fn = function() { console.log('foo'); };
  *     assert.doesNotChange(fn, obj, 'val');
  *
  * @name doesNotChange
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.doesNotChange = function (fn, obj, prop, msg) {
   if (arguments.length === 3 && typeof obj === 'function') {
     msg = prop;
     prop = null;
   }

   return new Assertion(fn, msg, assert.doesNotChange, true)
     .to.not.change(obj, prop);
 }

 /**
  * ### .changesButNotBy(function, object, property, delta, [message])
  *
  * Asserts that a function does not change the value of a property or of a function's return value by an amount (delta)
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val += 10 };
  *     assert.changesButNotBy(fn, obj, 'val', 5);
  *
  * @name changesButNotBy
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {Number} change amount (delta)
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.changesButNotBy = function (fn, obj, prop, delta, msg) {
   if (arguments.length === 4 && typeof obj === 'function') {
     var tmpMsg = delta;
     delta = prop;
     msg = tmpMsg;
   } else if (arguments.length === 3) {
     delta = prop;
     prop = null;
   }

   new Assertion(fn, msg, assert.changesButNotBy, true)
     .to.change(obj, prop).but.not.by(delta);
 }

 /**
  * ### .increases(function, object, property, [message])
  *
  * Asserts that a function increases a numeric object property.
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val = 13 };
  *     assert.increases(fn, obj, 'val');
  *
  * @name increases
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.increases = function (fn, obj, prop, msg) {
   if (arguments.length === 3 && typeof obj === 'function') {
     msg = prop;
     prop = null;
   }

   return new Assertion(fn, msg, assert.increases, true)
     .to.increase(obj, prop);
 }

 /**
  * ### .increasesBy(function, object, property, delta, [message])
  *
  * Asserts that a function increases a numeric object property or a function's return value by an amount (delta).
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val += 10 };
  *     assert.increasesBy(fn, obj, 'val', 10);
  *
  * @name increasesBy
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {Number} change amount (delta)
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.increasesBy = function (fn, obj, prop, delta, msg) {
   if (arguments.length === 4 && typeof obj === 'function') {
     var tmpMsg = delta;
     delta = prop;
     msg = tmpMsg;
   } else if (arguments.length === 3) {
     delta = prop;
     prop = null;
   }

   new Assertion(fn, msg, assert.increasesBy, true)
     .to.increase(obj, prop).by(delta);
 }

 /**
  * ### .doesNotIncrease(function, object, property, [message])
  *
  * Asserts that a function does not increase a numeric object property.
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val = 8 };
  *     assert.doesNotIncrease(fn, obj, 'val');
  *
  * @name doesNotIncrease
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.doesNotIncrease = function (fn, obj, prop, msg) {
   if (arguments.length === 3 && typeof obj === 'function') {
     msg = prop;
     prop = null;
   }

   return new Assertion(fn, msg, assert.doesNotIncrease, true)
     .to.not.increase(obj, prop);
 }

 /**
  * ### .increasesButNotBy(function, object, property, [message])
  *
  * Asserts that a function does not increase a numeric object property or function's return value by an amount (delta).
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val = 15 };
  *     assert.increasesButNotBy(fn, obj, 'val', 10);
  *
  * @name increasesButNotBy
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {Number} change amount (delta)
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.increasesButNotBy = function (fn, obj, prop, delta, msg) {
   if (arguments.length === 4 && typeof obj === 'function') {
     var tmpMsg = delta;
     delta = prop;
     msg = tmpMsg;
   } else if (arguments.length === 3) {
     delta = prop;
     prop = null;
   }

   new Assertion(fn, msg, assert.increasesButNotBy, true)
     .to.increase(obj, prop).but.not.by(delta);
 }

 /**
  * ### .decreases(function, object, property, [message])
  *
  * Asserts that a function decreases a numeric object property.
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val = 5 };
  *     assert.decreases(fn, obj, 'val');
  *
  * @name decreases
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.decreases = function (fn, obj, prop, msg) {
   if (arguments.length === 3 && typeof obj === 'function') {
     msg = prop;
     prop = null;
   }

   return new Assertion(fn, msg, assert.decreases, true)
     .to.decrease(obj, prop);
 }

 /**
  * ### .decreasesBy(function, object, property, delta, [message])
  *
  * Asserts that a function decreases a numeric object property or a function's return value by an amount (delta)
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val -= 5 };
  *     assert.decreasesBy(fn, obj, 'val', 5);
  *
  * @name decreasesBy
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {Number} change amount (delta)
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.decreasesBy = function (fn, obj, prop, delta, msg) {
   if (arguments.length === 4 && typeof obj === 'function') {
     var tmpMsg = delta;
     delta = prop;
     msg = tmpMsg;
   } else if (arguments.length === 3) {
     delta = prop;
     prop = null;
   }

   new Assertion(fn, msg, assert.decreasesBy, true)
     .to.decrease(obj, prop).by(delta);
 }

 /**
  * ### .doesNotDecrease(function, object, property, [message])
  *
  * Asserts that a function does not decreases a numeric object property.
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val = 15 };
  *     assert.doesNotDecrease(fn, obj, 'val');
  *
  * @name doesNotDecrease
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.doesNotDecrease = function (fn, obj, prop, msg) {
   if (arguments.length === 3 && typeof obj === 'function') {
     msg = prop;
     prop = null;
   }

   return new Assertion(fn, msg, assert.doesNotDecrease, true)
     .to.not.decrease(obj, prop);
 }

 /**
  * ### .doesNotDecreaseBy(function, object, property, delta, [message])
  *
  * Asserts that a function does not decreases a numeric object property or a function's return value by an amount (delta)
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val = 5 };
  *     assert.doesNotDecreaseBy(fn, obj, 'val', 1);
  *
  * @name doesNotDecrease
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {Number} change amount (delta)
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.doesNotDecreaseBy = function (fn, obj, prop, delta, msg) {
   if (arguments.length === 4 && typeof obj === 'function') {
     var tmpMsg = delta;
     delta = prop;
     msg = tmpMsg;
   } else if (arguments.length === 3) {
     delta = prop;
     prop = null;
   }

   return new Assertion(fn, msg, assert.doesNotDecreaseBy, true)
     .to.not.decrease(obj, prop).by(delta);
 }

 /**
  * ### .decreasesButNotBy(function, object, property, delta, [message])
  *
  * Asserts that a function does not decreases a numeric object property or a function's return value by an amount (delta)
  *
  *     var obj = { val: 10 };
  *     var fn = function() { obj.val = 5 };
  *     assert.decreasesButNotBy(fn, obj, 'val', 1);
  *
  * @name decreasesButNotBy
  * @param {Function} modifier function
  * @param {Object} object or getter function
  * @param {String} property name _optional_
  * @param {Number} change amount (delta)
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.decreasesButNotBy = function (fn, obj, prop, delta, msg) {
   if (arguments.length === 4 && typeof obj === 'function') {
     var tmpMsg = delta;
     delta = prop;
     msg = tmpMsg;
   } else if (arguments.length === 3) {
     delta = prop;
     prop = null;
   }

   new Assertion(fn, msg, assert.decreasesButNotBy, true)
     .to.decrease(obj, prop).but.not.by(delta);
 }

 /*!
  * ### .ifError(object)
  *
  * Asserts if value is not a false value, and throws if it is a true value.
  * This is added to allow for chai to be a drop-in replacement for Node's
  * assert class.
  *
  *     var err = new Error('I am a custom error');
  *     assert.ifError(err); // Rethrows err!
  *
  * @name ifError
  * @param {Object} object
  * @namespace Assert
  * @api public
  */

 assert.ifError = function (val) {
   if (val) {
     throw(val);
   }
 };

 /**
  * ### .isExtensible(object)
  *
  * Asserts that `object` is extensible (can have new properties added to it).
  *
  *     assert.isExtensible({});
  *
  * @name isExtensible
  * @alias extensible
  * @param {Object} object
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.isExtensible = function (obj, msg) {
   new Assertion(obj, msg, assert.isExtensible, true).to.be.extensible;
 };

 /**
  * ### .isNotExtensible(object)
  *
  * Asserts that `object` is _not_ extensible.
  *
  *     var nonExtensibleObject = Object.preventExtensions({});
  *     var sealedObject = Object.seal({});
  *     var frozenObject = Object.freeze({});
  *
  *     assert.isNotExtensible(nonExtensibleObject);
  *     assert.isNotExtensible(sealedObject);
  *     assert.isNotExtensible(frozenObject);
  *
  * @name isNotExtensible
  * @alias notExtensible
  * @param {Object} object
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.isNotExtensible = function (obj, msg) {
   new Assertion(obj, msg, assert.isNotExtensible, true).to.not.be.extensible;
 };

 /**
  * ### .isSealed(object)
  *
  * Asserts that `object` is sealed (cannot have new properties added to it
  * and its existing properties cannot be removed).
  *
  *     var sealedObject = Object.seal({});
  *     var frozenObject = Object.seal({});
  *
  *     assert.isSealed(sealedObject);
  *     assert.isSealed(frozenObject);
  *
  * @name isSealed
  * @alias sealed
  * @param {Object} object
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.isSealed = function (obj, msg) {
   new Assertion(obj, msg, assert.isSealed, true).to.be.sealed;
 };

 /**
  * ### .isNotSealed(object)
  *
  * Asserts that `object` is _not_ sealed.
  *
  *     assert.isNotSealed({});
  *
  * @name isNotSealed
  * @alias notSealed
  * @param {Object} object
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.isNotSealed = function (obj, msg) {
   new Assertion(obj, msg, assert.isNotSealed, true).to.not.be.sealed;
 };

 /**
  * ### .isFrozen(object)
  *
  * Asserts that `object` is frozen (cannot have new properties added to it
  * and its existing properties cannot be modified).
  *
  *     var frozenObject = Object.freeze({});
  *     assert.frozen(frozenObject);
  *
  * @name isFrozen
  * @alias frozen
  * @param {Object} object
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.isFrozen = function (obj, msg) {
   new Assertion(obj, msg, assert.isFrozen, true).to.be.frozen;
 };

 /**
  * ### .isNotFrozen(object)
  *
  * Asserts that `object` is _not_ frozen.
  *
  *     assert.isNotFrozen({});
  *
  * @name isNotFrozen
  * @alias notFrozen
  * @param {Object} object
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.isNotFrozen = function (obj, msg) {
   new Assertion(obj, msg, assert.isNotFrozen, true).to.not.be.frozen;
 };

 /**
  * ### .isEmpty(target)
  *
  * Asserts that the target does not contain any values.
  * For arrays and strings, it checks the `length` property.
  * For `Map` and `Set` instances, it checks the `size` property.
  * For non-function objects, it gets the count of own
  * enumerable string keys.
  *
  *     assert.isEmpty([]);
  *     assert.isEmpty('');
  *     assert.isEmpty(new Map);
  *     assert.isEmpty({});
  *
  * @name isEmpty
  * @alias empty
  * @param {Object|Array|String|Map|Set} target
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.isEmpty = function(val, msg) {
   new Assertion(val, msg, assert.isEmpty, true).to.be.empty;
 };

 /**
  * ### .isNotEmpty(target)
  *
  * Asserts that the target contains values.
  * For arrays and strings, it checks the `length` property.
  * For `Map` and `Set` instances, it checks the `size` property.
  * For non-function objects, it gets the count of own
  * enumerable string keys.
  *
  *     assert.isNotEmpty([1, 2]);
  *     assert.isNotEmpty('34');
  *     assert.isNotEmpty(new Set([5, 6]));
  *     assert.isNotEmpty({ key: 7 });
  *
  * @name isNotEmpty
  * @alias notEmpty
  * @param {Object|Array|String|Map|Set} target
  * @param {String} message _optional_
  * @namespace Assert
  * @api public
  */

 assert.isNotEmpty = function(val, msg) {
   new Assertion(val, msg, assert.isNotEmpty, true).to.not.be.empty;
 };

 /*!
  * Aliases.
  */

 (function alias(name, as){
   assert[as] = assert[name];
   return alias;
 })
 ('isOk', 'ok')
 ('isNotOk', 'notOk')
 ('throws', 'throw')
 ('throws', 'Throw')
 ('isExtensible', 'extensible')
 ('isNotExtensible', 'notExtensible')
 ('isSealed', 'sealed')
 ('isNotSealed', 'notSealed')
 ('isFrozen', 'frozen')
 ('isNotFrozen', 'notFrozen')
 ('isEmpty', 'empty')
 ('isNotEmpty', 'notEmpty');

};

},{}],7:[function(require,module,exports){ /*!

* chai
* Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

module.exports = function (chai, util) {

chai.expect = function (val, message) {
  return new chai.Assertion(val, message);
};

/**
 * ### .fail([message])
 * ### .fail(actual, expected, [message], [operator])
 *
 * Throw a failure.
 *
 *     expect.fail();
 *     expect.fail("custom error message");
 *     expect.fail(1, 2);
 *     expect.fail(1, 2, "custom error message");
 *     expect.fail(1, 2, "custom error message", ">");
 *     expect.fail(1, 2, undefined, ">");
 *
 * @name fail
 * @param {Mixed} actual
 * @param {Mixed} expected
 * @param {String} message
 * @param {String} operator
 * @namespace BDD
 * @api public
 */

chai.expect.fail = function (actual, expected, message, operator) {
  if (arguments.length < 2) {
      message = actual;
      actual = undefined;
  }

  message = message || 'expect.fail()';
  throw new chai.AssertionError(message, {
      actual: actual
    , expected: expected
    , operator: operator
  }, chai.expect.fail);
};

};

},{}],8:[function(require,module,exports){ /*!

* chai
* Copyright(c) 2011-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

module.exports = function (chai, util) {

var Assertion = chai.Assertion;

function loadShould () {
  // explicitly define this method as function as to have it's name to include as `ssfi`
  function shouldGetter() {
    if (this instanceof String
        || this instanceof Number
        || this instanceof Boolean
        || typeof Symbol === 'function' && this instanceof Symbol) {
      return new Assertion(this.valueOf(), null, shouldGetter);
    }
    return new Assertion(this, null, shouldGetter);
  }
  function shouldSetter(value) {
    // See https://github.com/chaijs/chai/issues/86: this makes
    // `whatever.should = someValue` actually set `someValue`, which is
    // especially useful for `global.should = require('chai').should()`.
    //
    // Note that we have to use [[DefineProperty]] instead of [[Put]]
    // since otherwise we would trigger this very setter!
    Object.defineProperty(this, 'should', {
      value: value,
      enumerable: true,
      configurable: true,
      writable: true
    });
  }
  // modify Object.prototype to have `should`
  Object.defineProperty(Object.prototype, 'should', {
    set: shouldSetter
    , get: shouldGetter
    , configurable: true
  });

  var should = {};

  /**
   * ### .fail([message])
   * ### .fail(actual, expected, [message], [operator])
   *
   * Throw a failure.
   *
   *     should.fail();
   *     should.fail("custom error message");
   *     should.fail(1, 2);
   *     should.fail(1, 2, "custom error message");
   *     should.fail(1, 2, "custom error message", ">");
   *     should.fail(1, 2, undefined, ">");
   *
   *
   * @name fail
   * @param {Mixed} actual
   * @param {Mixed} expected
   * @param {String} message
   * @param {String} operator
   * @namespace BDD
   * @api public
   */

  should.fail = function (actual, expected, message, operator) {
    if (arguments.length < 2) {
        message = actual;
        actual = undefined;
    }

    message = message || 'should.fail()';
    throw new chai.AssertionError(message, {
        actual: actual
      , expected: expected
      , operator: operator
    }, should.fail);
  };

  /**
   * ### .equal(actual, expected, [message])
   *
   * Asserts non-strict equality (`==`) of `actual` and `expected`.
   *
   *     should.equal(3, '3', '== coerces values to strings');
   *
   * @name equal
   * @param {Mixed} actual
   * @param {Mixed} expected
   * @param {String} message
   * @namespace Should
   * @api public
   */

  should.equal = function (val1, val2, msg) {
    new Assertion(val1, msg).to.equal(val2);
  };

  /**
   * ### .throw(function, [constructor/string/regexp], [string/regexp], [message])
   *
   * Asserts that `function` will throw an error that is an instance of
   * `constructor`, or alternately that it will throw an error with message
   * matching `regexp`.
   *
   *     should.throw(fn, 'function throws a reference error');
   *     should.throw(fn, /function throws a reference error/);
   *     should.throw(fn, ReferenceError);
   *     should.throw(fn, ReferenceError, 'function throws a reference error');
   *     should.throw(fn, ReferenceError, /function throws a reference error/);
   *
   * @name throw
   * @alias Throw
   * @param {Function} function
   * @param {ErrorConstructor} constructor
   * @param {RegExp} regexp
   * @param {String} message
   * @see https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Error#Error_types
   * @namespace Should
   * @api public
   */

  should.Throw = function (fn, errt, errs, msg) {
    new Assertion(fn, msg).to.Throw(errt, errs);
  };

  /**
   * ### .exist
   *
   * Asserts that the target is neither `null` nor `undefined`.
   *
   *     var foo = 'hi';
   *
   *     should.exist(foo, 'foo exists');
   *
   * @name exist
   * @namespace Should
   * @api public
   */

  should.exist = function (val, msg) {
    new Assertion(val, msg).to.exist;
  }

  // negation
  should.not = {}

  /**
   * ### .not.equal(actual, expected, [message])
   *
   * Asserts non-strict inequality (`!=`) of `actual` and `expected`.
   *
   *     should.not.equal(3, 4, 'these numbers are not equal');
   *
   * @name not.equal
   * @param {Mixed} actual
   * @param {Mixed} expected
   * @param {String} message
   * @namespace Should
   * @api public
   */

  should.not.equal = function (val1, val2, msg) {
    new Assertion(val1, msg).to.not.equal(val2);
  };

  /**
   * ### .throw(function, [constructor/regexp], [message])
   *
   * Asserts that `function` will _not_ throw an error that is an instance of
   * `constructor`, or alternately that it will not throw an error with message
   * matching `regexp`.
   *
   *     should.not.throw(fn, Error, 'function does not throw');
   *
   * @name not.throw
   * @alias not.Throw
   * @param {Function} function
   * @param {ErrorConstructor} constructor
   * @param {RegExp} regexp
   * @param {String} message
   * @see https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Error#Error_types
   * @namespace Should
   * @api public
   */

  should.not.Throw = function (fn, errt, errs, msg) {
    new Assertion(fn, msg).to.not.Throw(errt, errs);
  };

  /**
   * ### .not.exist
   *
   * Asserts that the target is neither `null` nor `undefined`.
   *
   *     var bar = null;
   *
   *     should.not.exist(bar, 'bar does not exist');
   *
   * @name not.exist
   * @namespace Should
   * @api public
   */

  should.not.exist = function (val, msg) {
    new Assertion(val, msg).to.not.exist;
  }

  should['throw'] = should['Throw'];
  should.not['throw'] = should.not['Throw'];

  return should;
};

chai.should = loadShould;
chai.Should = loadShould;

};

},{}],9:[function(require,module,exports){ /*!

* Chai - addChainingMethod utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/*!

* Module dependencies
*/

var addLengthGuard = require('./addLengthGuard'); var chai = require('../../chai'); var flag = require('./flag'); var proxify = require('./proxify'); var transferFlags = require('./transferFlags');

/*!

* Module variables
*/

// Check whether `Object.setPrototypeOf` is supported var canSetPrototype = typeof Object.setPrototypeOf === 'function';

// Without `Object.setPrototypeOf` support, this module will need to add properties to a function. // However, some of functions' own props are not configurable and should be skipped. var testFn = function() {}; var excludeNames = Object.getOwnPropertyNames(testFn).filter(function(name) {

var propDesc = Object.getOwnPropertyDescriptor(testFn, name);

// Note: PhantomJS 1.x includes `callee` as one of `testFn`'s own properties,
// but then returns `undefined` as the property descriptor for `callee`. As a
// workaround, we perform an otherwise unnecessary type-check for `propDesc`,
// and then filter it out if it's not an object as it should be.
if (typeof propDesc !== 'object')
  return true;

return !propDesc.configurable;

});

// Cache `Function` properties var call = Function.prototype.call,

apply = Function.prototype.apply;

/**

* ### .addChainableMethod(ctx, name, method, chainingBehavior)
*
* Adds a method to an object, such that the method can also be chained.
*
*     utils.addChainableMethod(chai.Assertion.prototype, 'foo', function (str) {
*       var obj = utils.flag(this, 'object');
*       new chai.Assertion(obj).to.be.equal(str);
*     });
*
* Can also be accessed directly from `chai.Assertion`.
*
*     chai.Assertion.addChainableMethod('foo', fn, chainingBehavior);
*
* The result can then be used as both a method assertion, executing both `method` and
* `chainingBehavior`, or as a language chain, which only executes `chainingBehavior`.
*
*     expect(fooStr).to.be.foo('bar');
*     expect(fooStr).to.be.foo.equal('foo');
*
* @param {Object} ctx object to which the method is added
* @param {String} name of method to add
* @param {Function} method function to be used for `name`, when called
* @param {Function} chainingBehavior function to be called every time the property is accessed
* @namespace Utils
* @name addChainableMethod
* @api public
*/

module.exports = function addChainableMethod(ctx, name, method, chainingBehavior) {

if (typeof chainingBehavior !== 'function') {
  chainingBehavior = function () { };
}

var chainableBehavior = {
    method: method
  , chainingBehavior: chainingBehavior
};

// save the methods so we can overwrite them later, if we need to.
if (!ctx.__methods) {
  ctx.__methods = {};
}
ctx.__methods[name] = chainableBehavior;

Object.defineProperty(ctx, name,
  { get: function chainableMethodGetter() {
      chainableBehavior.chainingBehavior.call(this);

      var chainableMethodWrapper = function () {
        // Setting the `ssfi` flag to `chainableMethodWrapper` causes this
        // function to be the starting point for removing implementation
        // frames from the stack trace of a failed assertion.
        //
        // However, we only want to use this function as the starting point if
        // the `lockSsfi` flag isn't set.
        //
        // If the `lockSsfi` flag is set, then this assertion is being
        // invoked from inside of another assertion. In this case, the `ssfi`
        // flag has already been set by the outer assertion.
        //
        // Note that overwriting a chainable method merely replaces the saved
        // methods in `ctx.__methods` instead of completely replacing the
        // overwritten assertion. Therefore, an overwriting assertion won't
        // set the `ssfi` or `lockSsfi` flags.
        if (!flag(this, 'lockSsfi')) {
          flag(this, 'ssfi', chainableMethodWrapper);
        }

        var result = chainableBehavior.method.apply(this, arguments);
        if (result !== undefined) {
          return result;
        }

        var newAssertion = new chai.Assertion();
        transferFlags(this, newAssertion);
        return newAssertion;
      };

      addLengthGuard(chainableMethodWrapper, name, true);

      // Use `Object.setPrototypeOf` if available
      if (canSetPrototype) {
        // Inherit all properties from the object by replacing the `Function` prototype
        var prototype = Object.create(this);
        // Restore the `call` and `apply` methods from `Function`
        prototype.call = call;
        prototype.apply = apply;
        Object.setPrototypeOf(chainableMethodWrapper, prototype);
      }
      // Otherwise, redefine all properties (slow!)
      else {
        var asserterNames = Object.getOwnPropertyNames(ctx);
        asserterNames.forEach(function (asserterName) {
          if (excludeNames.indexOf(asserterName) !== -1) {
            return;
          }

          var pd = Object.getOwnPropertyDescriptor(ctx, asserterName);
          Object.defineProperty(chainableMethodWrapper, asserterName, pd);
        });
      }

      transferFlags(this, chainableMethodWrapper);
      return proxify(chainableMethodWrapper);
    }
  , configurable: true
});

};

},{“../../chai”:2,“./addLengthGuard”:10,“./flag”:15,“./proxify”:30,“./transferFlags”:32}],10:[function(require,module,exports){ var fnLengthDesc = Object.getOwnPropertyDescriptor(function () {}, 'length');

/*!

* Chai - addLengthGuard utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .addLengthGuard(fn, assertionName, isChainable)
*
* Define `length` as a getter on the given uninvoked method assertion. The
* getter acts as a guard against chaining `length` directly off of an uninvoked
* method assertion, which is a problem because it references `function`'s
* built-in `length` property instead of Chai's `length` assertion. When the
* getter catches the user making this mistake, it throws an error with a
* helpful message.
*
* There are two ways in which this mistake can be made. The first way is by
* chaining the `length` assertion directly off of an uninvoked chainable
* method. In this case, Chai suggests that the user use `lengthOf` instead. The
* second way is by chaining the `length` assertion directly off of an uninvoked
* non-chainable method. Non-chainable methods must be invoked prior to
* chaining. In this case, Chai suggests that the user consult the docs for the
* given assertion.
*
* If the `length` property of functions is unconfigurable, then return `fn`
* without modification.
*
* Note that in ES6, the function's `length` property is configurable, so once
* support for legacy environments is dropped, Chai's `length` property can
* replace the built-in function's `length` property, and this length guard will
* no longer be necessary. In the mean time, maintaining consistency across all
* environments is the priority.
*
* @param {Function} fn
* @param {String} assertionName
* @param {Boolean} isChainable
* @namespace Utils
* @name addLengthGuard
*/

module.exports = function addLengthGuard (fn, assertionName, isChainable) {

if (!fnLengthDesc.configurable) return fn;

Object.defineProperty(fn, 'length', {
  get: function () {
    if (isChainable) {
      throw Error('Invalid Chai property: ' + assertionName + '.length. Due' +
        ' to a compatibility issue, "length" cannot directly follow "' +
        assertionName + '". Use "' + assertionName + '.lengthOf" instead.');
    }

    throw Error('Invalid Chai property: ' + assertionName + '.length. See' +
      ' docs for proper usage of "' + assertionName + '".');
  }
});

return fn;

};

},{}],11:[function(require,module,exports){ /*!

* Chai - addMethod utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

var addLengthGuard = require('./addLengthGuard'); var chai = require('../../chai'); var flag = require('./flag'); var proxify = require('./proxify'); var transferFlags = require('./transferFlags');

/**

* ### .addMethod(ctx, name, method)
*
* Adds a method to the prototype of an object.
*
*     utils.addMethod(chai.Assertion.prototype, 'foo', function (str) {
*       var obj = utils.flag(this, 'object');
*       new chai.Assertion(obj).to.be.equal(str);
*     });
*
* Can also be accessed directly from `chai.Assertion`.
*
*     chai.Assertion.addMethod('foo', fn);
*
* Then can be used as any other assertion.
*
*     expect(fooStr).to.be.foo('bar');
*
* @param {Object} ctx object to which the method is added
* @param {String} name of method to add
* @param {Function} method function to be used for name
* @namespace Utils
* @name addMethod
* @api public
*/

module.exports = function addMethod(ctx, name, method) {

var methodWrapper = function () {
  // Setting the `ssfi` flag to `methodWrapper` causes this function to be the
  // starting point for removing implementation frames from the stack trace of
  // a failed assertion.
  //
  // However, we only want to use this function as the starting point if the
  // `lockSsfi` flag isn't set.
  //
  // If the `lockSsfi` flag is set, then either this assertion has been
  // overwritten by another assertion, or this assertion is being invoked from
  // inside of another assertion. In the first case, the `ssfi` flag has
  // already been set by the overwriting assertion. In the second case, the
  // `ssfi` flag has already been set by the outer assertion.
  if (!flag(this, 'lockSsfi')) {
    flag(this, 'ssfi', methodWrapper);
  }

  var result = method.apply(this, arguments);
  if (result !== undefined)
    return result;

  var newAssertion = new chai.Assertion();
  transferFlags(this, newAssertion);
  return newAssertion;
};

addLengthGuard(methodWrapper, name, false);
ctx[name] = proxify(methodWrapper, name);

};

},{“../../chai”:2,“./addLengthGuard”:10,“./flag”:15,“./proxify”:30,“./transferFlags”:32}],12:[function(require,module,exports){ /*!

* Chai - addProperty utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

var chai = require('../../chai'); var flag = require('./flag'); var isProxyEnabled = require('./isProxyEnabled'); var transferFlags = require('./transferFlags');

/**

* ### .addProperty(ctx, name, getter)
*
* Adds a property to the prototype of an object.
*
*     utils.addProperty(chai.Assertion.prototype, 'foo', function () {
*       var obj = utils.flag(this, 'object');
*       new chai.Assertion(obj).to.be.instanceof(Foo);
*     });
*
* Can also be accessed directly from `chai.Assertion`.
*
*     chai.Assertion.addProperty('foo', fn);
*
* Then can be used as any other assertion.
*
*     expect(myFoo).to.be.foo;
*
* @param {Object} ctx object to which the property is added
* @param {String} name of property to add
* @param {Function} getter function to be used for name
* @namespace Utils
* @name addProperty
* @api public
*/

module.exports = function addProperty(ctx, name, getter) {

getter = getter === undefined ? function () {} : getter;

Object.defineProperty(ctx, name,
  { get: function propertyGetter() {
      // Setting the `ssfi` flag to `propertyGetter` causes this function to
      // be the starting point for removing implementation frames from the
      // stack trace of a failed assertion.
      //
      // However, we only want to use this function as the starting point if
      // the `lockSsfi` flag isn't set and proxy protection is disabled.
      //
      // If the `lockSsfi` flag is set, then either this assertion has been
      // overwritten by another assertion, or this assertion is being invoked
      // from inside of another assertion. In the first case, the `ssfi` flag
      // has already been set by the overwriting assertion. In the second
      // case, the `ssfi` flag has already been set by the outer assertion.
      //
      // If proxy protection is enabled, then the `ssfi` flag has already been
      // set by the proxy getter.
      if (!isProxyEnabled() && !flag(this, 'lockSsfi')) {
        flag(this, 'ssfi', propertyGetter);
      }

      var result = getter.call(this);
      if (result !== undefined)
        return result;

      var newAssertion = new chai.Assertion();
      transferFlags(this, newAssertion);
      return newAssertion;
    }
  , configurable: true
});

};

},{“../../chai”:2,“./flag”:15,“./isProxyEnabled”:25,“./transferFlags”:32}],13:[function(require,module,exports){ /*!

* Chai - compareByInspect utility
* Copyright(c) 2011-2016 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/*!

* Module dependencies
*/

var inspect = require('./inspect');

/**

* ### .compareByInspect(mixed, mixed)
*
* To be used as a compareFunction with Array.prototype.sort. Compares elements
* using inspect instead of default behavior of using toString so that Symbols
* and objects with irregular/missing toString can still be sorted without a
* TypeError.
*
* @param {Mixed} first element to compare
* @param {Mixed} second element to compare
* @returns {Number} -1 if 'a' should come before 'b'; otherwise 1
* @name compareByInspect
* @namespace Utils
* @api public
*/

module.exports = function compareByInspect(a, b) {

return inspect(a) < inspect(b) ? -1 : 1;

};

},{“./inspect”:23}],14:[function(require,module,exports){ /*!

* Chai - expectTypes utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .expectTypes(obj, types)
*
* Ensures that the object being tested against is of a valid type.
*
*     utils.expectTypes(this, ['array', 'object', 'string']);
*
* @param {Mixed} obj constructed Assertion
* @param {Array} type A list of allowed types for this assertion
* @namespace Utils
* @name expectTypes
* @api public
*/

var AssertionError = require('assertion-error'); var flag = require('./flag'); var type = require('type-detect');

module.exports = function expectTypes(obj, types) {

var flagMsg = flag(obj, 'message');
var ssfi = flag(obj, 'ssfi');

flagMsg = flagMsg ? flagMsg + ': ' : '';

obj = flag(obj, 'object');
types = types.map(function (t) { return t.toLowerCase(); });
types.sort();

// Transforms ['lorem', 'ipsum'] into 'a lorem, or an ipsum'
var str = types.map(function (t, index) {
  var art = ~[ 'a', 'e', 'i', 'o', 'u' ].indexOf(t.charAt(0)) ? 'an' : 'a';
  var or = types.length > 1 && index === types.length - 1 ? 'or ' : '';
  return or + art + ' ' + t;
}).join(', ');

var objType = type(obj).toLowerCase();

if (!types.some(function (expected) { return objType === expected; })) {
  throw new AssertionError(
    flagMsg + 'object tested must be ' + str + ', but ' + objType + ' given',
    undefined,
    ssfi
  );
}

};

},{“./flag”:15,“assertion-error”:33,“type-detect”:38}],15:[function(require,module,exports){ /*!

* Chai - flag utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .flag(object, key, [value])
*
* Get or set a flag value on an object. If a
* value is provided it will be set, else it will
* return the currently set value or `undefined` if
* the value is not set.
*
*     utils.flag(this, 'foo', 'bar'); // setter
*     utils.flag(this, 'foo'); // getter, returns `bar`
*
* @param {Object} object constructed Assertion
* @param {String} key
* @param {Mixed} value (optional)
* @namespace Utils
* @name flag
* @api private
*/

module.exports = function flag(obj, key, value) {

var flags = obj.__flags || (obj.__flags = Object.create(null));
if (arguments.length === 3) {
  flags[key] = value;
} else {
  return flags[key];
}

};

},{}],16:[function(require,module,exports){ /*!

* Chai - getActual utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .getActual(object, [actual])
*
* Returns the `actual` value for an Assertion.
*
* @param {Object} object (constructed Assertion)
* @param {Arguments} chai.Assertion.prototype.assert arguments
* @namespace Utils
* @name getActual
*/

module.exports = function getActual(obj, args) {

return args.length > 4 ? args[4] : obj._obj;

};

},{}],17:[function(require,module,exports){ /*!

* Chai - getEnumerableProperties utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .getEnumerableProperties(object)
*
* This allows the retrieval of enumerable property names of an object,
* inherited or not.
*
* @param {Object} object
* @returns {Array}
* @namespace Utils
* @name getEnumerableProperties
* @api public
*/

module.exports = function getEnumerableProperties(object) {

var result = [];
for (var name in object) {
  result.push(name);
}
return result;

};

},{}],18:[function(require,module,exports){ /*!

* Chai - message composition utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/*!

* Module dependencies
*/

var flag = require('./flag')

, getActual = require('./getActual')
, objDisplay = require('./objDisplay');

/**

* ### .getMessage(object, message, negateMessage)
*
* Construct the error message based on flags
* and template tags. Template tags will return
* a stringified inspection of the object referenced.
*
* Message template tags:
* - `#{this}` current asserted object
* - `#{act}` actual value
* - `#{exp}` expected value
*
* @param {Object} object (constructed Assertion)
* @param {Arguments} chai.Assertion.prototype.assert arguments
* @namespace Utils
* @name getMessage
* @api public
*/

module.exports = function getMessage(obj, args) {

var negate = flag(obj, 'negate')
  , val = flag(obj, 'object')
  , expected = args[3]
  , actual = getActual(obj, args)
  , msg = negate ? args[2] : args[1]
  , flagMsg = flag(obj, 'message');

if(typeof msg === "function") msg = msg();
msg = msg || '';
msg = msg
  .replace(/#\{this\}/g, function () { return objDisplay(val); })
  .replace(/#\{act\}/g, function () { return objDisplay(actual); })
  .replace(/#\{exp\}/g, function () { return objDisplay(expected); });

return flagMsg ? flagMsg + ': ' + msg : msg;

};

},{“./flag”:15,“./getActual”:16,“./objDisplay”:26}],19:[function(require,module,exports){ /*!

* Chai - getOwnEnumerableProperties utility
* Copyright(c) 2011-2016 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/*!

* Module dependencies
*/

var getOwnEnumerablePropertySymbols = require('./getOwnEnumerablePropertySymbols');

/**

* ### .getOwnEnumerableProperties(object)
*
* This allows the retrieval of directly-owned enumerable property names and
* symbols of an object. This function is necessary because Object.keys only
* returns enumerable property names, not enumerable property symbols.
*
* @param {Object} object
* @returns {Array}
* @namespace Utils
* @name getOwnEnumerableProperties
* @api public
*/

module.exports = function getOwnEnumerableProperties(obj) {

return Object.keys(obj).concat(getOwnEnumerablePropertySymbols(obj));

};

},{“./getOwnEnumerablePropertySymbols”:20}],20:[function(require,module,exports){ /*!

* Chai - getOwnEnumerablePropertySymbols utility
* Copyright(c) 2011-2016 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .getOwnEnumerablePropertySymbols(object)
*
* This allows the retrieval of directly-owned enumerable property symbols of an
* object. This function is necessary because Object.getOwnPropertySymbols
* returns both enumerable and non-enumerable property symbols.
*
* @param {Object} object
* @returns {Array}
* @namespace Utils
* @name getOwnEnumerablePropertySymbols
* @api public
*/

module.exports = function getOwnEnumerablePropertySymbols(obj) {

if (typeof Object.getOwnPropertySymbols !== 'function') return [];

return Object.getOwnPropertySymbols(obj).filter(function (sym) {
  return Object.getOwnPropertyDescriptor(obj, sym).enumerable;
});

};

},{}],21:[function(require,module,exports){ /*!

* Chai - getProperties utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .getProperties(object)
*
* This allows the retrieval of property names of an object, enumerable or not,
* inherited or not.
*
* @param {Object} object
* @returns {Array}
* @namespace Utils
* @name getProperties
* @api public
*/

module.exports = function getProperties(object) {

var result = Object.getOwnPropertyNames(object);

function addProperty(property) {
  if (result.indexOf(property) === -1) {
    result.push(property);
  }
}

var proto = Object.getPrototypeOf(object);
while (proto !== null) {
  Object.getOwnPropertyNames(proto).forEach(addProperty);
  proto = Object.getPrototypeOf(proto);
}

return result;

};

},{}],22:[function(require,module,exports){ /*!

* chai
* Copyright(c) 2011 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/*!

* Dependencies that are used for multiple exports are required here only once
*/

var pathval = require('pathval');

/*!

* test utility
*/

exports.test = require('./test');

/*!

* type utility
*/

exports.type = require('type-detect');

/*!

* expectTypes utility
*/

exports.expectTypes = require('./expectTypes');

/*!

* message utility
*/

exports.getMessage = require('./getMessage');

/*!

* actual utility
*/

exports.getActual = require('./getActual');

/*!

* Inspect util
*/

exports.inspect = require('./inspect');

/*!

* Object Display util
*/

exports.objDisplay = require('./objDisplay');

/*!

* Flag utility
*/

exports.flag = require('./flag');

/*!

* Flag transferring utility
*/

exports.transferFlags = require('./transferFlags');

/*!

* Deep equal utility
*/

exports.eql = require('deep-eql');

/*!

* Deep path info
*/

exports.getPathInfo = pathval.getPathInfo;

/*!

* Check if a property exists
*/

exports.hasProperty = pathval.hasProperty;

/*!

* Function name
*/

exports.getName = require('get-func-name');

/*!

* add Property
*/

exports.addProperty = require('./addProperty');

/*!

* add Method
*/

exports.addMethod = require('./addMethod');

/*!

* overwrite Property
*/

exports.overwriteProperty = require('./overwriteProperty');

/*!

* overwrite Method
*/

exports.overwriteMethod = require('./overwriteMethod');

/*!

* Add a chainable method
*/

exports.addChainableMethod = require('./addChainableMethod');

/*!

* Overwrite chainable method
*/

exports.overwriteChainableMethod = require('./overwriteChainableMethod');

/*!

* Compare by inspect method
*/

exports.compareByInspect = require('./compareByInspect');

/*!

* Get own enumerable property symbols method
*/

exports.getOwnEnumerablePropertySymbols = require('./getOwnEnumerablePropertySymbols');

/*!

* Get own enumerable properties method
*/

exports.getOwnEnumerableProperties = require('./getOwnEnumerableProperties');

/*!

* Checks error against a given set of criteria
*/

exports.checkError = require('check-error');

/*!

* Proxify util
*/

exports.proxify = require('./proxify');

/*!

* addLengthGuard util
*/

exports.addLengthGuard = require('./addLengthGuard');

/*!

* isProxyEnabled helper
*/

exports.isProxyEnabled = require('./isProxyEnabled');

/*!

* isNaN method
*/

exports.isNaN = require('./isNaN');

},{“./addChainableMethod”:9,“./addLengthGuard”:10,“./addMethod”:11,“./addProperty”:12,“./compareByInspect”:13,“./expectTypes”:14,“./flag”:15,“./getActual”:16,“./getMessage”:18,“./getOwnEnumerableProperties”:19,“./getOwnEnumerablePropertySymbols”:20,“./inspect”:23,“./isNaN”:24,“./isProxyEnabled”:25,“./objDisplay”:26,“./overwriteChainableMethod”:27,“./overwriteMethod”:28,“./overwriteProperty”:29,“./proxify”:30,“./test”:31,“./transferFlags”:32,“check-error”:34,“deep-eql”:35,“get-func-name”:36,“pathval”:37,“type-detect”:38}],23:[function(require,module,exports){ // This is (almost) directly from Node.js utils // github.com/joyent/node/blob/f8c335d0caf47f16d31413f89aa28eda3878e3aa/lib/util.js

var getName = require('get-func-name'); var getProperties = require('./getProperties'); var getEnumerableProperties = require('./getEnumerableProperties'); var config = require('../config');

module.exports = inspect;

/**

* ### .inspect(obj, [showHidden], [depth], [colors])
*
* Echoes the value of a value. Tries to print the value out
* in the best way possible given the different types.
*
* @param {Object} obj The object to print out.
* @param {Boolean} showHidden Flag that shows hidden (not enumerable)
*    properties of objects. Default is false.
* @param {Number} depth Depth in which to descend in object. Default is 2.
* @param {Boolean} colors Flag to turn on ANSI escape codes to color the
*    output. Default is false (no coloring).
* @namespace Utils
* @name inspect
*/

function inspect(obj, showHidden, depth, colors) {

var ctx = {
  showHidden: showHidden,
  seen: [],
  stylize: function (str) { return str; }
};
return formatValue(ctx, obj, (typeof depth === 'undefined' ? 2 : depth));

}

// Returns true if object is a DOM element. var isDOMElement = function (object) {

if (typeof HTMLElement === 'object') {
  return object instanceof HTMLElement;
} else {
  return object &&
    typeof object === 'object' &&
    'nodeType' in object &&
    object.nodeType === 1 &&
    typeof object.nodeName === 'string';
}

};

function formatValue(ctx, value, recurseTimes) {

// Provide a hook for user-specified inspect functions.
// Check that value is an object with an inspect function on it
if (value && typeof value.inspect === 'function' &&
    // Filter out the util module, it's inspect function is special
    value.inspect !== exports.inspect &&
    // Also filter out any prototype objects using the circular check.
    !(value.constructor && value.constructor.prototype === value)) {
  var ret = value.inspect(recurseTimes, ctx);
  if (typeof ret !== 'string') {
    ret = formatValue(ctx, ret, recurseTimes);
  }
  return ret;
}

// Primitive types cannot have properties
var primitive = formatPrimitive(ctx, value);
if (primitive) {
  return primitive;
}

// If this is a DOM element, try to get the outer HTML.
if (isDOMElement(value)) {
  if ('outerHTML' in value) {
    return value.outerHTML;
    // This value does not have an outerHTML attribute,
    //   it could still be an XML element
  } else {
    // Attempt to serialize it
    try {
      if (document.xmlVersion) {
        var xmlSerializer = new XMLSerializer();
        return xmlSerializer.serializeToString(value);
      } else {
        // Firefox 11- do not support outerHTML
        //   It does, however, support innerHTML
        //   Use the following to render the element
        var ns = "http://www.w3.org/1999/xhtml";
        var container = document.createElementNS(ns, '_');

        container.appendChild(value.cloneNode(false));
        var html = container.innerHTML
          .replace('><', '>' + value.innerHTML + '<');
        container.innerHTML = '';
        return html;
      }
    } catch (err) {
      // This could be a non-native DOM implementation,
      //   continue with the normal flow:
      //   printing the element as if it is an object.
    }
  }
}

// Look up the keys of the object.
var visibleKeys = getEnumerableProperties(value);
var keys = ctx.showHidden ? getProperties(value) : visibleKeys;

var name, nameSuffix;

// Some type of object without properties can be shortcut.
// In IE, errors have a single `stack` property, or if they are vanilla `Error`,
// a `stack` plus `description` property; ignore those for consistency.
if (keys.length === 0 || (isError(value) && (
    (keys.length === 1 && keys[0] === 'stack') ||
    (keys.length === 2 && keys[0] === 'description' && keys[1] === 'stack')
   ))) {
  if (typeof value === 'function') {
    name = getName(value);
    nameSuffix = name ? ': ' + name : '';
    return ctx.stylize('[Function' + nameSuffix + ']', 'special');
  }
  if (isRegExp(value)) {
    return ctx.stylize(RegExp.prototype.toString.call(value), 'regexp');
  }
  if (isDate(value)) {
    return ctx.stylize(Date.prototype.toUTCString.call(value), 'date');
  }
  if (isError(value)) {
    return formatError(value);
  }
}

var base = ''
  , array = false
  , typedArray = false
  , braces = ['{', '}'];

if (isTypedArray(value)) {
  typedArray = true;
  braces = ['[', ']'];
}

// Make Array say that they are Array
if (isArray(value)) {
  array = true;
  braces = ['[', ']'];
}

// Make functions say that they are functions
if (typeof value === 'function') {
  name = getName(value);
  nameSuffix = name ? ': ' + name : '';
  base = ' [Function' + nameSuffix + ']';
}

// Make RegExps say that they are RegExps
if (isRegExp(value)) {
  base = ' ' + RegExp.prototype.toString.call(value);
}

// Make dates with properties first say the date
if (isDate(value)) {
  base = ' ' + Date.prototype.toUTCString.call(value);
}

// Make error with message first say the error
if (isError(value)) {
  return formatError(value);
}

if (keys.length === 0 && (!array || value.length == 0)) {
  return braces[0] + base + braces[1];
}

if (recurseTimes < 0) {
  if (isRegExp(value)) {
    return ctx.stylize(RegExp.prototype.toString.call(value), 'regexp');
  } else {
    return ctx.stylize('[Object]', 'special');
  }
}

ctx.seen.push(value);

var output;
if (array) {
  output = formatArray(ctx, value, recurseTimes, visibleKeys, keys);
} else if (typedArray) {
  return formatTypedArray(value);
} else {
  output = keys.map(function(key) {
    return formatProperty(ctx, value, recurseTimes, visibleKeys, key, array);
  });
}

ctx.seen.pop();

return reduceToSingleString(output, base, braces);

}

function formatPrimitive(ctx, value) {

switch (typeof value) {
  case 'undefined':
    return ctx.stylize('undefined', 'undefined');

  case 'string':
    var simple = '\'' + JSON.stringify(value).replace(/^"|"$/g, '')
                                             .replace(/'/g, "\\'")
                                             .replace(/\\"/g, '"') + '\'';
    return ctx.stylize(simple, 'string');

  case 'number':
    if (value === 0 && (1/value) === -Infinity) {
      return ctx.stylize('-0', 'number');
    }
    return ctx.stylize('' + value, 'number');

  case 'boolean':
    return ctx.stylize('' + value, 'boolean');

  case 'symbol':
    return ctx.stylize(value.toString(), 'symbol');
}
// For some reason typeof null is "object", so special case here.
if (value === null) {
  return ctx.stylize('null', 'null');
}

}

function formatError(value) {

return '[' + Error.prototype.toString.call(value) + ']';

}

function formatArray(ctx, value, recurseTimes, visibleKeys, keys) {

var output = [];
for (var i = 0, l = value.length; i < l; ++i) {
  if (Object.prototype.hasOwnProperty.call(value, String(i))) {
    output.push(formatProperty(ctx, value, recurseTimes, visibleKeys,
        String(i), true));
  } else {
    output.push('');
  }
}

keys.forEach(function(key) {
  if (!key.match(/^\d+$/)) {
    output.push(formatProperty(ctx, value, recurseTimes, visibleKeys,
        key, true));
  }
});
return output;

}

function formatTypedArray(value) {

var str = '[ ';

for (var i = 0; i < value.length; ++i) {
  if (str.length >= config.truncateThreshold - 7) {
    str += '...';
    break;
  }
  str += value[i] + ', ';
}
str += ' ]';

// Removing trailing `, ` if the array was not truncated
if (str.indexOf(',  ]') !== -1) {
  str = str.replace(',  ]', ' ]');
}

return str;

}

function formatProperty(ctx, value, recurseTimes, visibleKeys, key, array) {

var name;
var propDescriptor = Object.getOwnPropertyDescriptor(value, key);
var str;

if (propDescriptor) {
  if (propDescriptor.get) {
    if (propDescriptor.set) {
      str = ctx.stylize('[Getter/Setter]', 'special');
    } else {
      str = ctx.stylize('[Getter]', 'special');
    }
  } else {
    if (propDescriptor.set) {
      str = ctx.stylize('[Setter]', 'special');
    }
  }
}
if (visibleKeys.indexOf(key) < 0) {
  name = '[' + key + ']';
}
if (!str) {
  if (ctx.seen.indexOf(value[key]) < 0) {
    if (recurseTimes === null) {
      str = formatValue(ctx, value[key], null);
    } else {
      str = formatValue(ctx, value[key], recurseTimes - 1);
    }
    if (str.indexOf('\n') > -1) {
      if (array) {
        str = str.split('\n').map(function(line) {
          return '  ' + line;
        }).join('\n').substr(2);
      } else {
        str = '\n' + str.split('\n').map(function(line) {
          return '   ' + line;
        }).join('\n');
      }
    }
  } else {
    str = ctx.stylize('[Circular]', 'special');
  }
}
if (typeof name === 'undefined') {
  if (array && key.match(/^\d+$/)) {
    return str;
  }
  name = JSON.stringify('' + key);
  if (name.match(/^"([a-zA-Z_][a-zA-Z_0-9]*)"$/)) {
    name = name.substr(1, name.length - 2);
    name = ctx.stylize(name, 'name');
  } else {
    name = name.replace(/'/g, "\\'")
               .replace(/\\"/g, '"')
               .replace(/(^"|"$)/g, "'");
    name = ctx.stylize(name, 'string');
  }
}

return name + ': ' + str;

}

function reduceToSingleString(output, base, braces) {

var length = output.reduce(function(prev, cur) {
  return prev + cur.length + 1;
}, 0);

if (length > 60) {
  return braces[0] +
         (base === '' ? '' : base + '\n ') +
         ' ' +
         output.join(',\n  ') +
         ' ' +
         braces[1];
}

return braces[0] + base + ' ' + output.join(', ') + ' ' + braces[1];

}

function isTypedArray(ar) {

// Unfortunately there's no way to check if an object is a TypedArray
// We have to check if it's one of these types
return (typeof ar === 'object' && /\w+Array]$/.test(objectToString(ar)));

}

function isArray(ar) {

return Array.isArray(ar) ||
       (typeof ar === 'object' && objectToString(ar) === '[object Array]');

}

function isRegExp(re) {

return typeof re === 'object' && objectToString(re) === '[object RegExp]';

}

function isDate(d) {

return typeof d === 'object' && objectToString(d) === '[object Date]';

}

function isError(e) {

return typeof e === 'object' && objectToString(e) === '[object Error]';

}

function objectToString(o) {

return Object.prototype.toString.call(o);

}

},{“../config”:4,“./getEnumerableProperties”:17,“./getProperties”:21,“get-func-name”:36}],24:[function(require,module,exports){ /*!

* Chai - isNaN utility
* Copyright(c) 2012-2015 Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
* MIT Licensed
*/

/**

* ### .isNaN(value)
*
* Checks if the given value is NaN or not.
*
*     utils.isNaN(NaN); // true
*
* @param {Value} The value which has to be checked if it is NaN
* @name isNaN
* @api private
*/

function isNaN(value) {

// Refer http://www.ecma-international.org/ecma-262/6.0/#sec-isnan-number
// section's NOTE.
return value !== value;

}

// If ECMAScript 6's Number.isNaN is present, prefer that. module.exports = Number.isNaN || isNaN;

},{}],25:[function(require,module,exports){ var config = require('../config');

/*!

* Chai - isProxyEnabled helper
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .isProxyEnabled()
*
* Helper function to check if Chai's proxy protection feature is enabled. If
* proxies are unsupported or disabled via the user's Chai config, then return
* false. Otherwise, return true.
*
* @namespace Utils
* @name isProxyEnabled
*/

module.exports = function isProxyEnabled() {

return config.useProxy &&
  typeof Proxy !== 'undefined' &&
  typeof Reflect !== 'undefined';

};

},{“../config”:4}],26:[function(require,module,exports){ /*!

* Chai - flag utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/*!

* Module dependencies
*/

var inspect = require('./inspect'); var config = require('../config');

/**

* ### .objDisplay(object)
*
* Determines if an object or an array matches
* criteria to be inspected in-line for error
* messages or should be truncated.
*
* @param {Mixed} javascript object to inspect
* @name objDisplay
* @namespace Utils
* @api public
*/

module.exports = function objDisplay(obj) {

var str = inspect(obj)
  , type = Object.prototype.toString.call(obj);

if (config.truncateThreshold && str.length >= config.truncateThreshold) {
  if (type === '[object Function]') {
    return !obj.name || obj.name === ''
      ? '[Function]'
      : '[Function: ' + obj.name + ']';
  } else if (type === '[object Array]') {
    return '[ Array(' + obj.length + ') ]';
  } else if (type === '[object Object]') {
    var keys = Object.keys(obj)
      , kstr = keys.length > 2
        ? keys.splice(0, 2).join(', ') + ', ...'
        : keys.join(', ');
    return '{ Object (' + kstr + ') }';
  } else {
    return str;
  }
} else {
  return str;
}

};

},{“../config”:4,“./inspect”:23}],27:[function(require,module,exports){ /*!

* Chai - overwriteChainableMethod utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

var chai = require('../../chai'); var transferFlags = require('./transferFlags');

/**

* ### .overwriteChainableMethod(ctx, name, method, chainingBehavior)
*
* Overwrites an already existing chainable method
* and provides access to the previous function or
* property.  Must return functions to be used for
* name.
*
*     utils.overwriteChainableMethod(chai.Assertion.prototype, 'lengthOf',
*       function (_super) {
*       }
*     , function (_super) {
*       }
*     );
*
* Can also be accessed directly from `chai.Assertion`.
*
*     chai.Assertion.overwriteChainableMethod('foo', fn, fn);
*
* Then can be used as any other assertion.
*
*     expect(myFoo).to.have.lengthOf(3);
*     expect(myFoo).to.have.lengthOf.above(3);
*
* @param {Object} ctx object whose method / property is to be overwritten
* @param {String} name of method / property to overwrite
* @param {Function} method function that returns a function to be used for name
* @param {Function} chainingBehavior function that returns a function to be used for property
* @namespace Utils
* @name overwriteChainableMethod
* @api public
*/

module.exports = function overwriteChainableMethod(ctx, name, method, chainingBehavior) {

var chainableBehavior = ctx.__methods[name];

var _chainingBehavior = chainableBehavior.chainingBehavior;
chainableBehavior.chainingBehavior = function overwritingChainableMethodGetter() {
  var result = chainingBehavior(_chainingBehavior).call(this);
  if (result !== undefined) {
    return result;
  }

  var newAssertion = new chai.Assertion();
  transferFlags(this, newAssertion);
  return newAssertion;
};

var _method = chainableBehavior.method;
chainableBehavior.method = function overwritingChainableMethodWrapper() {
  var result = method(_method).apply(this, arguments);
  if (result !== undefined) {
    return result;
  }

  var newAssertion = new chai.Assertion();
  transferFlags(this, newAssertion);
  return newAssertion;
};

};

},{“../../chai”:2,“./transferFlags”:32}],28:[function(require,module,exports){ /*!

* Chai - overwriteMethod utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

var addLengthGuard = require('./addLengthGuard'); var chai = require('../../chai'); var flag = require('./flag'); var proxify = require('./proxify'); var transferFlags = require('./transferFlags');

/**

* ### .overwriteMethod(ctx, name, fn)
*
* Overwrites an already existing method and provides
* access to previous function. Must return function
* to be used for name.
*
*     utils.overwriteMethod(chai.Assertion.prototype, 'equal', function (_super) {
*       return function (str) {
*         var obj = utils.flag(this, 'object');
*         if (obj instanceof Foo) {
*           new chai.Assertion(obj.value).to.equal(str);
*         } else {
*           _super.apply(this, arguments);
*         }
*       }
*     });
*
* Can also be accessed directly from `chai.Assertion`.
*
*     chai.Assertion.overwriteMethod('foo', fn);
*
* Then can be used as any other assertion.
*
*     expect(myFoo).to.equal('bar');
*
* @param {Object} ctx object whose method is to be overwritten
* @param {String} name of method to overwrite
* @param {Function} method function that returns a function to be used for name
* @namespace Utils
* @name overwriteMethod
* @api public
*/

module.exports = function overwriteMethod(ctx, name, method) {

var _method = ctx[name]
  , _super = function () {
    throw new Error(name + ' is not a function');
  };

if (_method && 'function' === typeof _method)
  _super = _method;

var overwritingMethodWrapper = function () {
  // Setting the `ssfi` flag to `overwritingMethodWrapper` causes this
  // function to be the starting point for removing implementation frames from
  // the stack trace of a failed assertion.
  //
  // However, we only want to use this function as the starting point if the
  // `lockSsfi` flag isn't set.
  //
  // If the `lockSsfi` flag is set, then either this assertion has been
  // overwritten by another assertion, or this assertion is being invoked from
  // inside of another assertion. In the first case, the `ssfi` flag has
  // already been set by the overwriting assertion. In the second case, the
  // `ssfi` flag has already been set by the outer assertion.
  if (!flag(this, 'lockSsfi')) {
    flag(this, 'ssfi', overwritingMethodWrapper);
  }

  // Setting the `lockSsfi` flag to `true` prevents the overwritten assertion
  // from changing the `ssfi` flag. By this point, the `ssfi` flag is already
  // set to the correct starting point for this assertion.
  var origLockSsfi = flag(this, 'lockSsfi');
  flag(this, 'lockSsfi', true);
  var result = method(_super).apply(this, arguments);
  flag(this, 'lockSsfi', origLockSsfi);

  if (result !== undefined) {
    return result;
  }

  var newAssertion = new chai.Assertion();
  transferFlags(this, newAssertion);
  return newAssertion;
}

addLengthGuard(overwritingMethodWrapper, name, false);
ctx[name] = proxify(overwritingMethodWrapper, name);

};

},{“../../chai”:2,“./addLengthGuard”:10,“./flag”:15,“./proxify”:30,“./transferFlags”:32}],29:[function(require,module,exports){ /*!

* Chai - overwriteProperty utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

var chai = require('../../chai'); var flag = require('./flag'); var isProxyEnabled = require('./isProxyEnabled'); var transferFlags = require('./transferFlags');

/**

* ### .overwriteProperty(ctx, name, fn)
*
* Overwrites an already existing property getter and provides
* access to previous value. Must return function to use as getter.
*
*     utils.overwriteProperty(chai.Assertion.prototype, 'ok', function (_super) {
*       return function () {
*         var obj = utils.flag(this, 'object');
*         if (obj instanceof Foo) {
*           new chai.Assertion(obj.name).to.equal('bar');
*         } else {
*           _super.call(this);
*         }
*       }
*     });
*
*
* Can also be accessed directly from `chai.Assertion`.
*
*     chai.Assertion.overwriteProperty('foo', fn);
*
* Then can be used as any other assertion.
*
*     expect(myFoo).to.be.ok;
*
* @param {Object} ctx object whose property is to be overwritten
* @param {String} name of property to overwrite
* @param {Function} getter function that returns a getter function to be used for name
* @namespace Utils
* @name overwriteProperty
* @api public
*/

module.exports = function overwriteProperty(ctx, name, getter) {

var _get = Object.getOwnPropertyDescriptor(ctx, name)
  , _super = function () {};

if (_get && 'function' === typeof _get.get)
  _super = _get.get

Object.defineProperty(ctx, name,
  { get: function overwritingPropertyGetter() {
      // Setting the `ssfi` flag to `overwritingPropertyGetter` causes this
      // function to be the starting point for removing implementation frames
      // from the stack trace of a failed assertion.
      //
      // However, we only want to use this function as the starting point if
      // the `lockSsfi` flag isn't set and proxy protection is disabled.
      //
      // If the `lockSsfi` flag is set, then either this assertion has been
      // overwritten by another assertion, or this assertion is being invoked
      // from inside of another assertion. In the first case, the `ssfi` flag
      // has already been set by the overwriting assertion. In the second
      // case, the `ssfi` flag has already been set by the outer assertion.
      //
      // If proxy protection is enabled, then the `ssfi` flag has already been
      // set by the proxy getter.
      if (!isProxyEnabled() && !flag(this, 'lockSsfi')) {
        flag(this, 'ssfi', overwritingPropertyGetter);
      }

      // Setting the `lockSsfi` flag to `true` prevents the overwritten
      // assertion from changing the `ssfi` flag. By this point, the `ssfi`
      // flag is already set to the correct starting point for this assertion.
      var origLockSsfi = flag(this, 'lockSsfi');
      flag(this, 'lockSsfi', true);
      var result = getter(_super).call(this);
      flag(this, 'lockSsfi', origLockSsfi);

      if (result !== undefined) {
        return result;
      }

      var newAssertion = new chai.Assertion();
      transferFlags(this, newAssertion);
      return newAssertion;
    }
  , configurable: true
});

};

},{“../../chai”:2,“./flag”:15,“./isProxyEnabled”:25,“./transferFlags”:32}],30:[function(require,module,exports){ var config = require('../config'); var flag = require('./flag'); var getProperties = require('./getProperties'); var isProxyEnabled = require('./isProxyEnabled');

/*!

* Chai - proxify utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .proxify(object)
*
* Return a proxy of given object that throws an error when a non-existent
* property is read. By default, the root cause is assumed to be a misspelled
* property, and thus an attempt is made to offer a reasonable suggestion from
* the list of existing properties. However, if a nonChainableMethodName is
* provided, then the root cause is instead a failure to invoke a non-chainable
* method prior to reading the non-existent property.
*
* If proxies are unsupported or disabled via the user's Chai config, then
* return object without modification.
*
* @param {Object} obj
* @param {String} nonChainableMethodName
* @namespace Utils
* @name proxify
*/

var builtins = ['__flags', '__methods', '_obj', 'assert'];

module.exports = function proxify(obj, nonChainableMethodName) {

if (!isProxyEnabled()) return obj;

return new Proxy(obj, {
  get: function proxyGetter(target, property) {
    // This check is here because we should not throw errors on Symbol properties
    // such as `Symbol.toStringTag`.
    // The values for which an error should be thrown can be configured using
    // the `config.proxyExcludedKeys` setting.
    if (typeof property === 'string' &&
        config.proxyExcludedKeys.indexOf(property) === -1 &&
        !Reflect.has(target, property)) {
      // Special message for invalid property access of non-chainable methods.
      if (nonChainableMethodName) {
        throw Error('Invalid Chai property: ' + nonChainableMethodName + '.' +
          property + '. See docs for proper usage of "' +
          nonChainableMethodName + '".');
      }

      // If the property is reasonably close to an existing Chai property,
      // suggest that property to the user. Only suggest properties with a
      // distance less than 4.
      var suggestion = null;
      var suggestionDistance = 4;
      getProperties(target).forEach(function(prop) {
        if (
          !Object.prototype.hasOwnProperty(prop) &&
          builtins.indexOf(prop) === -1
        ) {
          var dist = stringDistanceCapped(
            property,
            prop,
            suggestionDistance
          );
          if (dist < suggestionDistance) {
            suggestion = prop;
            suggestionDistance = dist;
          }
        }
      });

      if (suggestion !== null) {
        throw Error('Invalid Chai property: ' + property +
          '. Did you mean "' + suggestion + '"?');
      } else {
        throw Error('Invalid Chai property: ' + property);
      }
    }

    // Use this proxy getter as the starting point for removing implementation
    // frames from the stack trace of a failed assertion. For property
    // assertions, this prevents the proxy getter from showing up in the stack
    // trace since it's invoked before the property getter. For method and
    // chainable method assertions, this flag will end up getting changed to
    // the method wrapper, which is good since this frame will no longer be in
    // the stack once the method is invoked. Note that Chai builtin assertion
    // properties such as `__flags` are skipped since this is only meant to
    // capture the starting point of an assertion. This step is also skipped
    // if the `lockSsfi` flag is set, thus indicating that this assertion is
    // being called from within another assertion. In that case, the `ssfi`
    // flag is already set to the outer assertion's starting point.
    if (builtins.indexOf(property) === -1 && !flag(target, 'lockSsfi')) {
      flag(target, 'ssfi', proxyGetter);
    }

    return Reflect.get(target, property);
  }
});

};

/**

* # stringDistanceCapped(strA, strB, cap)
* Return the Levenshtein distance between two strings, but no more than cap.
* @param {string} strA
* @param {string} strB
* @param {number} number
* @return {number} min(string distance between strA and strB, cap)
* @api private
*/

function stringDistanceCapped(strA, strB, cap) {

if (Math.abs(strA.length - strB.length) >= cap) {
  return cap;
}

var memo = [];
// `memo` is a two-dimensional array containing distances.
// memo[i][j] is the distance between strA.slice(0, i) and
// strB.slice(0, j).
for (var i = 0; i <= strA.length; i++) {
  memo[i] = Array(strB.length + 1).fill(0);
  memo[i][0] = i;
}
for (var j = 0; j < strB.length; j++) {
  memo[0][j] = j;
}

for (var i = 1; i <= strA.length; i++) {
  var ch = strA.charCodeAt(i - 1);
  for (var j = 1; j <= strB.length; j++) {
    if (Math.abs(i - j) >= cap) {
      memo[i][j] = cap;
      continue;
    }
    memo[i][j] = Math.min(
      memo[i - 1][j] + 1,
      memo[i][j - 1] + 1,
      memo[i - 1][j - 1] +
        (ch === strB.charCodeAt(j - 1) ? 0 : 1)
    );
  }
}

return memo[strA.length][strB.length];

}

},{“../config”:4,“./flag”:15,“./getProperties”:21,“./isProxyEnabled”:25}],31:[function(require,module,exports){ /*!

* Chai - test utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/*!

* Module dependencies
*/

var flag = require('./flag');

/**

* ### .test(object, expression)
*
* Test and object for expression.
*
* @param {Object} object (constructed Assertion)
* @param {Arguments} chai.Assertion.prototype.assert arguments
* @namespace Utils
* @name test
*/

module.exports = function test(obj, args) {

var negate = flag(obj, 'negate')
  , expr = args[0];
return negate ? !expr : expr;

};

},{“./flag”:15}],32:[function(require,module,exports){ /*!

* Chai - transferFlags utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .transferFlags(assertion, object, includeAll = true)
*
* Transfer all the flags for `assertion` to `object`. If
* `includeAll` is set to `false`, then the base Chai
* assertion flags (namely `object`, `ssfi`, `lockSsfi`,
* and `message`) will not be transferred.
*
*
*     var newAssertion = new Assertion();
*     utils.transferFlags(assertion, newAssertion);
*
*     var anotherAssertion = new Assertion(myObj);
*     utils.transferFlags(assertion, anotherAssertion, false);
*
* @param {Assertion} assertion the assertion to transfer the flags from
* @param {Object} object the object to transfer the flags to; usually a new assertion
* @param {Boolean} includeAll
* @namespace Utils
* @name transferFlags
* @api private
*/

module.exports = function transferFlags(assertion, object, includeAll) {

var flags = assertion.__flags || (assertion.__flags = Object.create(null));

if (!object.__flags) {
  object.__flags = Object.create(null);
}

includeAll = arguments.length === 3 ? includeAll : true;

for (var flag in flags) {
  if (includeAll ||
      (flag !== 'object' && flag !== 'ssfi' && flag !== 'lockSsfi' && flag != 'message')) {
    object.__flags[flag] = flags[flag];
  }
}

};

},{}],33:[function(require,module,exports){ /*!

* assertion-error
* Copyright(c) 2013 Jake Luer <jake@qualiancy.com>
* MIT Licensed
*/

/*!

* Return a function that will copy properties from
* one object to another excluding any originally
* listed. Returned function will create a new `{}`.
*
* @param {String} excluded properties ...
* @return {Function}
*/

function exclude () {

var excludes = [].slice.call(arguments);

function excludeProps (res, obj) {
  Object.keys(obj).forEach(function (key) {
    if (!~excludes.indexOf(key)) res[key] = obj[key];
  });
}

return function extendExclude () {
  var args = [].slice.call(arguments)
    , i = 0
    , res = {};

  for (; i < args.length; i++) {
    excludeProps(res, args[i]);
  }

  return res;
};

};

/*!

* Primary Exports
*/

module.exports = AssertionError;

/**

* ### AssertionError
*
* An extension of the JavaScript `Error` constructor for
* assertion and validation scenarios.
*
* @param {String} message
* @param {Object} properties to include (optional)
* @param {callee} start stack function (optional)
*/

function AssertionError (message, _props, ssf) {

var extend = exclude('name', 'message', 'stack', 'constructor', 'toJSON')
  , props = extend(_props || {});

// default values
this.message = message || 'Unspecified AssertionError';
this.showDiff = false;

// copy from properties
for (var key in props) {
  this[key] = props[key];
}

// capture stack trace
ssf = ssf || AssertionError;
if (Error.captureStackTrace) {
  Error.captureStackTrace(this, ssf);
} else {
  try {
    throw new Error();
  } catch(e) {
    this.stack = e.stack;
  }
}

}

/*!

* Inherit from Error.prototype
*/

AssertionError.prototype = Object.create(Error.prototype);

/*!

* Statically set name
*/

AssertionError.prototype.name = 'AssertionError';

/*!

* Ensure correct constructor
*/

AssertionError.prototype.constructor = AssertionError;

/**

* Allow errors to be converted to JSON for static transfer.
*
* @param {Boolean} include stack (default: `true`)
* @return {Object} object that can be `JSON.stringify`
*/

AssertionError.prototype.toJSON = function (stack) {

var extend = exclude('constructor', 'toJSON', 'stack')
  , props = extend({ name: this.name }, this);

// include stack if exists and not turned off
if (false !== stack && this.stack) {
  props.stack = this.stack;
}

return props;

};

},{}],34:[function(require,module,exports){ 'use strict';

/* !

* Chai - checkError utility
* Copyright(c) 2012-2016 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .checkError
*
* Checks that an error conforms to a given set of criteria and/or retrieves information about it.
*
* @api public
*/

/**

* ### .compatibleInstance(thrown, errorLike)
*
* Checks if two instances are compatible (strict equal).
* Returns false if errorLike is not an instance of Error, because instances
* can only be compatible if they're both error instances.
*
* @name compatibleInstance
* @param {Error} thrown error
* @param {Error|ErrorConstructor} errorLike object to compare against
* @namespace Utils
* @api public
*/

function compatibleInstance(thrown, errorLike) {

return errorLike instanceof Error && thrown === errorLike;

}

/**

* ### .compatibleConstructor(thrown, errorLike)
*
* Checks if two constructors are compatible.
* This function can receive either an error constructor or
* an error instance as the `errorLike` argument.
* Constructors are compatible if they're the same or if one is
* an instance of another.
*
* @name compatibleConstructor
* @param {Error} thrown error
* @param {Error|ErrorConstructor} errorLike object to compare against
* @namespace Utils
* @api public
*/

function compatibleConstructor(thrown, errorLike) {

if (errorLike instanceof Error) {
  // If `errorLike` is an instance of any error we compare their constructors
  return thrown.constructor === errorLike.constructor || thrown instanceof errorLike.constructor;
} else if (errorLike.prototype instanceof Error || errorLike === Error) {
  // If `errorLike` is a constructor that inherits from Error, we compare `thrown` to `errorLike` directly
  return thrown.constructor === errorLike || thrown instanceof errorLike;
}

return false;

}

/**

* ### .compatibleMessage(thrown, errMatcher)
*
* Checks if an error's message is compatible with a matcher (String or RegExp).
* If the message contains the String or passes the RegExp test,
* it is considered compatible.
*
* @name compatibleMessage
* @param {Error} thrown error
* @param {String|RegExp} errMatcher to look for into the message
* @namespace Utils
* @api public
*/

function compatibleMessage(thrown, errMatcher) {

var comparisonString = typeof thrown === 'string' ? thrown : thrown.message;
if (errMatcher instanceof RegExp) {
  return errMatcher.test(comparisonString);
} else if (typeof errMatcher === 'string') {
  return comparisonString.indexOf(errMatcher) !== -1; // eslint-disable-line no-magic-numbers
}

return false;

}

/**

* ### .getFunctionName(constructorFn)
*
* Returns the name of a function.
* This also includes a polyfill function if `constructorFn.name` is not defined.
*
* @name getFunctionName
* @param {Function} constructorFn
* @namespace Utils
* @api private
*/

var functionNameMatch = /s*function(?:s|s*/*+*/s*)*(+)/; function getFunctionName(constructorFn) {

var name = '';
if (typeof constructorFn.name === 'undefined') {
  // Here we run a polyfill if constructorFn.name is not defined
  var match = String(constructorFn).match(functionNameMatch);
  if (match) {
    name = match[1];
  }
} else {
  name = constructorFn.name;
}

return name;

}

/**

* ### .getConstructorName(errorLike)
*
* Gets the constructor name for an Error instance or constructor itself.
*
* @name getConstructorName
* @param {Error|ErrorConstructor} errorLike
* @namespace Utils
* @api public
*/

function getConstructorName(errorLike) {

var constructorName = errorLike;
if (errorLike instanceof Error) {
  constructorName = getFunctionName(errorLike.constructor);
} else if (typeof errorLike === 'function') {
  // If `err` is not an instance of Error it is an error constructor itself or another function.
  // If we've got a common function we get its name, otherwise we may need to create a new instance
  // of the error just in case it's a poorly-constructed error. Please see chaijs/chai/issues/45 to know more.
  constructorName = getFunctionName(errorLike).trim() ||
      getFunctionName(new errorLike()); // eslint-disable-line new-cap
}

return constructorName;

}

/**

* ### .getMessage(errorLike)
*
* Gets the error message from an error.
* If `err` is a String itself, we return it.
* If the error has no message, we return an empty string.
*
* @name getMessage
* @param {Error|String} errorLike
* @namespace Utils
* @api public
*/

function getMessage(errorLike) {

var msg = '';
if (errorLike && errorLike.message) {
  msg = errorLike.message;
} else if (typeof errorLike === 'string') {
  msg = errorLike;
}

return msg;

}

module.exports = {

compatibleInstance: compatibleInstance,
compatibleConstructor: compatibleConstructor,
compatibleMessage: compatibleMessage,
getMessage: getMessage,
getConstructorName: getConstructorName,

};

},{}],35:[function(require,module,exports){ 'use strict'; /* globals Symbol: false, Uint8Array: false, WeakMap: false */ /*!

* deep-eql
* Copyright(c) 2013 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

var type = require('type-detect'); function FakeMap() {

this._key = 'chai/deep-eql__' + Math.random() + Date.now();

}

FakeMap.prototype = {

get: function getMap(key) {
  return key[this._key];
},
set: function setMap(key, value) {
  if (Object.isExtensible(key)) {
    Object.defineProperty(key, this._key, {
      value: value,
      configurable: true,
    });
  }
},

};

var MemoizeMap = typeof WeakMap === 'function' ? WeakMap : FakeMap; /*!

* Check to see if the MemoizeMap has recorded a result of the two operands
*
* @param {Mixed} leftHandOperand
* @param {Mixed} rightHandOperand
* @param {MemoizeMap} memoizeMap
* @returns {Boolean|null} result

*/ function memoizeCompare(leftHandOperand, rightHandOperand, memoizeMap) {

// Technically, WeakMap keys can *only* be objects, not primitives.
if (!memoizeMap || isPrimitive(leftHandOperand) || isPrimitive(rightHandOperand)) {
  return null;
}
var leftHandMap = memoizeMap.get(leftHandOperand);
if (leftHandMap) {
  var result = leftHandMap.get(rightHandOperand);
  if (typeof result === 'boolean') {
    return result;
  }
}
return null;

}

/*!

* Set the result of the equality into the MemoizeMap
*
* @param {Mixed} leftHandOperand
* @param {Mixed} rightHandOperand
* @param {MemoizeMap} memoizeMap
* @param {Boolean} result

*/ function memoizeSet(leftHandOperand, rightHandOperand, memoizeMap, result) {

// Technically, WeakMap keys can *only* be objects, not primitives.
if (!memoizeMap || isPrimitive(leftHandOperand) || isPrimitive(rightHandOperand)) {
  return;
}
var leftHandMap = memoizeMap.get(leftHandOperand);
if (leftHandMap) {
  leftHandMap.set(rightHandOperand, result);
} else {
  leftHandMap = new MemoizeMap();
  leftHandMap.set(rightHandOperand, result);
  memoizeMap.set(leftHandOperand, leftHandMap);
}

}

/*!

* Primary Export
*/

module.exports = deepEqual; module.exports.MemoizeMap = MemoizeMap;

/**

* Assert deeply nested sameValue equality between two objects of any type.
*
* @param {Mixed} leftHandOperand
* @param {Mixed} rightHandOperand
* @param {Object} [options] (optional) Additional options
* @param {Array} [options.comparator] (optional) Override default algorithm, determining custom equality.
* @param {Array} [options.memoize] (optional) Provide a custom memoization object which will cache the results of
   complex objects for a speed boost. By passing `false` you can disable memoization, but this will cause circular
   references to blow the stack.
* @return {Boolean} equal match
*/

function deepEqual(leftHandOperand, rightHandOperand, options) {

// If we have a comparator, we can't assume anything; so bail to its check first.
if (options && options.comparator) {
  return extensiveDeepEqual(leftHandOperand, rightHandOperand, options);
}

var simpleResult = simpleEqual(leftHandOperand, rightHandOperand);
if (simpleResult !== null) {
  return simpleResult;
}

// Deeper comparisons are pushed through to a larger function
return extensiveDeepEqual(leftHandOperand, rightHandOperand, options);

}

/**

* Many comparisons can be canceled out early via simple equality or primitive checks.
* @param {Mixed} leftHandOperand
* @param {Mixed} rightHandOperand
* @return {Boolean|null} equal match
*/

function simpleEqual(leftHandOperand, rightHandOperand) {

// Equal references (except for Numbers) can be returned early
if (leftHandOperand === rightHandOperand) {
  // Handle +-0 cases
  return leftHandOperand !== 0 || 1 / leftHandOperand === 1 / rightHandOperand;
}

// handle NaN cases
if (
  leftHandOperand !== leftHandOperand && // eslint-disable-line no-self-compare
  rightHandOperand !== rightHandOperand // eslint-disable-line no-self-compare
) {
  return true;
}

// Anything that is not an 'object', i.e. symbols, functions, booleans, numbers,
// strings, and undefined, can be compared by reference.
if (isPrimitive(leftHandOperand) || isPrimitive(rightHandOperand)) {
  // Easy out b/c it would have passed the first equality check
  return false;
}
return null;

}

/*!

* The main logic of the `deepEqual` function.
*
* @param {Mixed} leftHandOperand
* @param {Mixed} rightHandOperand
* @param {Object} [options] (optional) Additional options
* @param {Array} [options.comparator] (optional) Override default algorithm, determining custom equality.
* @param {Array} [options.memoize] (optional) Provide a custom memoization object which will cache the results of
   complex objects for a speed boost. By passing `false` you can disable memoization, but this will cause circular
   references to blow the stack.
* @return {Boolean} equal match

*/ function extensiveDeepEqual(leftHandOperand, rightHandOperand, options) {

options = options || {};
options.memoize = options.memoize === false ? false : options.memoize || new MemoizeMap();
var comparator = options && options.comparator;

// Check if a memoized result exists.
var memoizeResultLeft = memoizeCompare(leftHandOperand, rightHandOperand, options.memoize);
if (memoizeResultLeft !== null) {
  return memoizeResultLeft;
}
var memoizeResultRight = memoizeCompare(rightHandOperand, leftHandOperand, options.memoize);
if (memoizeResultRight !== null) {
  return memoizeResultRight;
}

// If a comparator is present, use it.
if (comparator) {
  var comparatorResult = comparator(leftHandOperand, rightHandOperand);
  // Comparators may return null, in which case we want to go back to default behavior.
  if (comparatorResult === false || comparatorResult === true) {
    memoizeSet(leftHandOperand, rightHandOperand, options.memoize, comparatorResult);
    return comparatorResult;
  }
  // To allow comparators to override *any* behavior, we ran them first. Since it didn't decide
  // what to do, we need to make sure to return the basic tests first before we move on.
  var simpleResult = simpleEqual(leftHandOperand, rightHandOperand);
  if (simpleResult !== null) {
    // Don't memoize this, it takes longer to set/retrieve than to just compare.
    return simpleResult;
  }
}

var leftHandType = type(leftHandOperand);
if (leftHandType !== type(rightHandOperand)) {
  memoizeSet(leftHandOperand, rightHandOperand, options.memoize, false);
  return false;
}

// Temporarily set the operands in the memoize object to prevent blowing the stack
memoizeSet(leftHandOperand, rightHandOperand, options.memoize, true);

var result = extensiveDeepEqualByType(leftHandOperand, rightHandOperand, leftHandType, options);
memoizeSet(leftHandOperand, rightHandOperand, options.memoize, result);
return result;

}

function extensiveDeepEqualByType(leftHandOperand, rightHandOperand, leftHandType, options) {

switch (leftHandType) {
  case 'String':
  case 'Number':
  case 'Boolean':
  case 'Date':
    // If these types are their instance types (e.g. `new Number`) then re-deepEqual against their values
    return deepEqual(leftHandOperand.valueOf(), rightHandOperand.valueOf());
  case 'Promise':
  case 'Symbol':
  case 'function':
  case 'WeakMap':
  case 'WeakSet':
  case 'Error':
    return leftHandOperand === rightHandOperand;
  case 'Arguments':
  case 'Int8Array':
  case 'Uint8Array':
  case 'Uint8ClampedArray':
  case 'Int16Array':
  case 'Uint16Array':
  case 'Int32Array':
  case 'Uint32Array':
  case 'Float32Array':
  case 'Float64Array':
  case 'Array':
    return iterableEqual(leftHandOperand, rightHandOperand, options);
  case 'RegExp':
    return regexpEqual(leftHandOperand, rightHandOperand);
  case 'Generator':
    return generatorEqual(leftHandOperand, rightHandOperand, options);
  case 'DataView':
    return iterableEqual(new Uint8Array(leftHandOperand.buffer), new Uint8Array(rightHandOperand.buffer), options);
  case 'ArrayBuffer':
    return iterableEqual(new Uint8Array(leftHandOperand), new Uint8Array(rightHandOperand), options);
  case 'Set':
    return entriesEqual(leftHandOperand, rightHandOperand, options);
  case 'Map':
    return entriesEqual(leftHandOperand, rightHandOperand, options);
  default:
    return objectEqual(leftHandOperand, rightHandOperand, options);
}

}

/*!

* Compare two Regular Expressions for equality.
*
* @param {RegExp} leftHandOperand
* @param {RegExp} rightHandOperand
* @return {Boolean} result
*/

function regexpEqual(leftHandOperand, rightHandOperand) {

return leftHandOperand.toString() === rightHandOperand.toString();

}

/*!

* Compare two Sets/Maps for equality. Faster than other equality functions.
*
* @param {Set} leftHandOperand
* @param {Set} rightHandOperand
* @param {Object} [options] (Optional)
* @return {Boolean} result
*/

function entriesEqual(leftHandOperand, rightHandOperand, options) {

// IE11 doesn't support Set#entries or Set#@@iterator, so we need manually populate using Set#forEach
if (leftHandOperand.size !== rightHandOperand.size) {
  return false;
}
if (leftHandOperand.size === 0) {
  return true;
}
var leftHandItems = [];
var rightHandItems = [];
leftHandOperand.forEach(function gatherEntries(key, value) {
  leftHandItems.push([ key, value ]);
});
rightHandOperand.forEach(function gatherEntries(key, value) {
  rightHandItems.push([ key, value ]);
});
return iterableEqual(leftHandItems.sort(), rightHandItems.sort(), options);

}

/*!

* Simple equality for flat iterable objects such as Arrays, TypedArrays or Node.js buffers.
*
* @param {Iterable} leftHandOperand
* @param {Iterable} rightHandOperand
* @param {Object} [options] (Optional)
* @return {Boolean} result
*/

function iterableEqual(leftHandOperand, rightHandOperand, options) {

var length = leftHandOperand.length;
if (length !== rightHandOperand.length) {
  return false;
}
if (length === 0) {
  return true;
}
var index = -1;
while (++index < length) {
  if (deepEqual(leftHandOperand[index], rightHandOperand[index], options) === false) {
    return false;
  }
}
return true;

}

/*!

* Simple equality for generator objects such as those returned by generator functions.
*
* @param {Iterable} leftHandOperand
* @param {Iterable} rightHandOperand
* @param {Object} [options] (Optional)
* @return {Boolean} result
*/

function generatorEqual(leftHandOperand, rightHandOperand, options) {

return iterableEqual(getGeneratorEntries(leftHandOperand), getGeneratorEntries(rightHandOperand), options);

}

/*!

* Determine if the given object has an @@iterator function.
*
* @param {Object} target
* @return {Boolean} `true` if the object has an @@iterator function.
*/

function hasIteratorFunction(target) {

return typeof Symbol !== 'undefined' &&
  typeof target === 'object' &&
  typeof Symbol.iterator !== 'undefined' &&
  typeof target[Symbol.iterator] === 'function';

}

/*!

* Gets all iterator entries from the given Object. If the Object has no @@iterator function, returns an empty array.
* This will consume the iterator - which could have side effects depending on the @@iterator implementation.
*
* @param {Object} target
* @returns {Array} an array of entries from the @@iterator function
*/

function getIteratorEntries(target) {

if (hasIteratorFunction(target)) {
  try {
    return getGeneratorEntries(target[Symbol.iterator]());
  } catch (iteratorError) {
    return [];
  }
}
return [];

}

/*!

* Gets all entries from a Generator. This will consume the generator - which could have side effects.
*
* @param {Generator} target
* @returns {Array} an array of entries from the Generator.
*/

function getGeneratorEntries(generator) {

var generatorResult = generator.next();
var accumulator = [ generatorResult.value ];
while (generatorResult.done === false) {
  generatorResult = generator.next();
  accumulator.push(generatorResult.value);
}
return accumulator;

}

/*!

* Gets all own and inherited enumerable keys from a target.
*
* @param {Object} target
* @returns {Array} an array of own and inherited enumerable keys from the target.
*/

function getEnumerableKeys(target) {

var keys = [];
for (var key in target) {
  keys.push(key);
}
return keys;

}

/*!

* Determines if two objects have matching values, given a set of keys. Defers to deepEqual for the equality check of
* each key. If any value of the given key is not equal, the function will return false (early).
*
* @param {Mixed} leftHandOperand
* @param {Mixed} rightHandOperand
* @param {Array} keys An array of keys to compare the values of leftHandOperand and rightHandOperand against
* @param {Object} [options] (Optional)
* @return {Boolean} result
*/

function keysEqual(leftHandOperand, rightHandOperand, keys, options) {

var length = keys.length;
if (length === 0) {
  return true;
}
for (var i = 0; i < length; i += 1) {
  if (deepEqual(leftHandOperand[keys[i]], rightHandOperand[keys[i]], options) === false) {
    return false;
  }
}
return true;

}

/*!

* Recursively check the equality of two Objects. Once basic sameness has been established it will defer to `deepEqual`
* for each enumerable key in the object.
*
* @param {Mixed} leftHandOperand
* @param {Mixed} rightHandOperand
* @param {Object} [options] (Optional)
* @return {Boolean} result
*/

function objectEqual(leftHandOperand, rightHandOperand, options) {

var leftHandKeys = getEnumerableKeys(leftHandOperand);
var rightHandKeys = getEnumerableKeys(rightHandOperand);
if (leftHandKeys.length && leftHandKeys.length === rightHandKeys.length) {
  leftHandKeys.sort();
  rightHandKeys.sort();
  if (iterableEqual(leftHandKeys, rightHandKeys) === false) {
    return false;
  }
  return keysEqual(leftHandOperand, rightHandOperand, leftHandKeys, options);
}

var leftHandEntries = getIteratorEntries(leftHandOperand);
var rightHandEntries = getIteratorEntries(rightHandOperand);
if (leftHandEntries.length && leftHandEntries.length === rightHandEntries.length) {
  leftHandEntries.sort();
  rightHandEntries.sort();
  return iterableEqual(leftHandEntries, rightHandEntries, options);
}

if (leftHandKeys.length === 0 &&
    leftHandEntries.length === 0 &&
    rightHandKeys.length === 0 &&
    rightHandEntries.length === 0) {
  return true;
}

return false;

}

/*!

* Returns true if the argument is a primitive.
*
* This intentionally returns true for all objects that can be compared by reference,
* including functions and symbols.
*
* @param {Mixed} value
* @return {Boolean} result
*/

function isPrimitive(value) {

return value === null || typeof value !== 'object';

}

},{“type-detect”:38}],36:[function(require,module,exports){ 'use strict';

/* !

* Chai - getFuncName utility
* Copyright(c) 2012-2016 Jake Luer <jake@alogicalparadox.com>
* MIT Licensed
*/

/**

* ### .getFuncName(constructorFn)
*
* Returns the name of a function.
* When a non-function instance is passed, returns `null`.
* This also includes a polyfill function if `aFunc.name` is not defined.
*
* @name getFuncName
* @param {Function} funct
* @namespace Utils
* @api public
*/

var toString = Function.prototype.toString; var functionNameMatch = /s*function(?:s|s*/*+*/s*)*(+)/; function getFuncName(aFunc) {

if (typeof aFunc !== 'function') {
  return null;
}

var name = '';
if (typeof Function.prototype.name === 'undefined' && typeof aFunc.name === 'undefined') {
  // Here we run a polyfill if Function does not support the `name` property and if aFunc.name is not defined
  var match = toString.call(aFunc).match(functionNameMatch);
  if (match) {
    name = match[1];
  }
} else {
  // If we've got a `name` property we just use it
  name = aFunc.name;
}

return name;

}

module.exports = getFuncName;

},{}],37:[function(require,module,exports){ 'use strict';

/* !

* Chai - pathval utility
* Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
* @see https://github.com/logicalparadox/filtr
* MIT Licensed
*/

/**

* ### .hasProperty(object, name)
*
* This allows checking whether an object has own
* or inherited from prototype chain named property.
*
* Basically does the same thing as the `in`
* operator but works properly with null/undefined values
* and other primitives.
*
*     var obj = {
*         arr: ['a', 'b', 'c']
*       , str: 'Hello'
*     }
*
* The following would be the results.
*
*     hasProperty(obj, 'str');  // true
*     hasProperty(obj, 'constructor');  // true
*     hasProperty(obj, 'bar');  // false
*
*     hasProperty(obj.str, 'length'); // true
*     hasProperty(obj.str, 1);  // true
*     hasProperty(obj.str, 5);  // false
*
*     hasProperty(obj.arr, 'length');  // true
*     hasProperty(obj.arr, 2);  // true
*     hasProperty(obj.arr, 3);  // false
*
* @param {Object} object
* @param {String|Symbol} name
* @returns {Boolean} whether it exists
* @namespace Utils
* @name hasProperty
* @api public
*/

function hasProperty(obj, name) {

if (typeof obj === 'undefined' || obj === null) {
  return false;
}

// The `in` operator does not work with primitives.
return name in Object(obj);

}

/* !

* ## parsePath(path)
*
* Helper function used to parse string object
* paths. Use in conjunction with `internalGetPathValue`.
*
*      var parsed = parsePath('myobject.property.subprop');
*
* ### Paths:
*
* * Can be infinitely deep and nested.
* * Arrays are also valid using the formal `myobject.document[3].property`.
* * Literal dots and brackets (not delimiter) must be backslash-escaped.
*
* @param {String} path
* @returns {Object} parsed
* @api private
*/

function parsePath(path) {

var str = path.replace(/([^\\])\[/g, '$1.[');
var parts = str.match(/(\\\.|[^.]+?)+/g);
return parts.map(function mapMatches(value) {
  var regexp = /^\[(\d+)\]$/;
  var mArr = regexp.exec(value);
  var parsed = null;
  if (mArr) {
    parsed = { i: parseFloat(mArr[1]) };
  } else {
    parsed = { p: value.replace(/\\([.\[\]])/g, '$1') };
  }

  return parsed;
});

}

/* !

* ## internalGetPathValue(obj, parsed[, pathDepth])
*
* Helper companion function for `.parsePath` that returns
* the value located at the parsed address.
*
*      var value = getPathValue(obj, parsed);
*
* @param {Object} object to search against
* @param {Object} parsed definition from `parsePath`.
* @param {Number} depth (nesting level) of the property we want to retrieve
* @returns {Object|Undefined} value
* @api private
*/

function internalGetPathValue(obj, parsed, pathDepth) {

var temporaryValue = obj;
var res = null;
pathDepth = (typeof pathDepth === 'undefined' ? parsed.length : pathDepth);

for (var i = 0; i < pathDepth; i++) {
  var part = parsed[i];
  if (temporaryValue) {
    if (typeof part.p === 'undefined') {
      temporaryValue = temporaryValue[part.i];
    } else {
      temporaryValue = temporaryValue[part.p];
    }

    if (i === (pathDepth - 1)) {
      res = temporaryValue;
    }
  }
}

return res;

}

/* !

* ## internalSetPathValue(obj, value, parsed)
*
* Companion function for `parsePath` that sets
* the value located at a parsed address.
*
*  internalSetPathValue(obj, 'value', parsed);
*
* @param {Object} object to search and define on
* @param {*} value to use upon set
* @param {Object} parsed definition from `parsePath`
* @api private
*/

function internalSetPathValue(obj, val, parsed) {

var tempObj = obj;
var pathDepth = parsed.length;
var part = null;
// Here we iterate through every part of the path
for (var i = 0; i < pathDepth; i++) {
  var propName = null;
  var propVal = null;
  part = parsed[i];

  // If it's the last part of the path, we set the 'propName' value with the property name
  if (i === (pathDepth - 1)) {
    propName = typeof part.p === 'undefined' ? part.i : part.p;
    // Now we set the property with the name held by 'propName' on object with the desired val
    tempObj[propName] = val;
  } else if (typeof part.p !== 'undefined' && tempObj[part.p]) {
    tempObj = tempObj[part.p];
  } else if (typeof part.i !== 'undefined' && tempObj[part.i]) {
    tempObj = tempObj[part.i];
  } else {
    // If the obj doesn't have the property we create one with that name to define it
    var next = parsed[i + 1];
    // Here we set the name of the property which will be defined
    propName = typeof part.p === 'undefined' ? part.i : part.p;
    // Here we decide if this property will be an array or a new object
    propVal = typeof next.p === 'undefined' ? [] : {};
    tempObj[propName] = propVal;
    tempObj = tempObj[propName];
  }
}

}

/**

* ### .getPathInfo(object, path)
*
* This allows the retrieval of property info in an
* object given a string path.
*
* The path info consists of an object with the
* following properties:
*
* * parent - The parent object of the property referenced by `path`
* * name - The name of the final property, a number if it was an array indexer
* * value - The value of the property, if it exists, otherwise `undefined`
* * exists - Whether the property exists or not
*
* @param {Object} object
* @param {String} path
* @returns {Object} info
* @namespace Utils
* @name getPathInfo
* @api public
*/

function getPathInfo(obj, path) {

var parsed = parsePath(path);
var last = parsed[parsed.length - 1];
var info = {
  parent: parsed.length > 1 ? internalGetPathValue(obj, parsed, parsed.length - 1) : obj,
  name: last.p || last.i,
  value: internalGetPathValue(obj, parsed),
};
info.exists = hasProperty(info.parent, info.name);

return info;

}

/**

* ### .getPathValue(object, path)
*
* This allows the retrieval of values in an
* object given a string path.
*
*     var obj = {
*         prop1: {
*             arr: ['a', 'b', 'c']
*           , str: 'Hello'
*         }
*       , prop2: {
*             arr: [ { nested: 'Universe' } ]
*           , str: 'Hello again!'
*         }
*     }
*
* The following would be the results.
*
*     getPathValue(obj, 'prop1.str'); // Hello
*     getPathValue(obj, 'prop1.att[2]'); // b
*     getPathValue(obj, 'prop2.arr[0].nested'); // Universe
*
* @param {Object} object
* @param {String} path
* @returns {Object} value or `undefined`
* @namespace Utils
* @name getPathValue
* @api public
*/

function getPathValue(obj, path) {

var info = getPathInfo(obj, path);
return info.value;

}

/**

* ### .setPathValue(object, path, value)
*
* Define the value in an object at a given string path.
*
* ```js
* var obj = {
*     prop1: {
*         arr: ['a', 'b', 'c']
*       , str: 'Hello'
*     }
*   , prop2: {
*         arr: [ { nested: 'Universe' } ]
*       , str: 'Hello again!'
*     }
* };
* ```
*
* The following would be acceptable.
*
* ```js
* var properties = require('tea-properties');
* properties.set(obj, 'prop1.str', 'Hello Universe!');
* properties.set(obj, 'prop1.arr[2]', 'B');
* properties.set(obj, 'prop2.arr[0].nested.value', { hello: 'universe' });
* ```
*
* @param {Object} object
* @param {String} path
* @param {Mixed} value
* @api private
*/

function setPathValue(obj, path, val) {

var parsed = parsePath(path);
internalSetPathValue(obj, val, parsed);
return obj;

}

module.exports = {

hasProperty: hasProperty,
getPathInfo: getPathInfo,
getPathValue: getPathValue,
setPathValue: setPathValue,

};

},{}],38:[function(require,module,exports){ (function (global, factory) {

typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
typeof define === 'function' && define.amd ? define(factory) :
(global.typeDetect = factory());

}(this, (function () { 'use strict';

/* !

* type-detect
* Copyright(c) 2013 jake luer <jake@alogicalparadox.com>
* MIT Licensed
*/

var promiseExists = typeof Promise === 'function';

/* eslint-disable no-undef */ var globalObject = typeof self === 'object' ? self : global; // eslint-disable-line id-blacklist

var symbolExists = typeof Symbol !== 'undefined'; var mapExists = typeof Map !== 'undefined'; var setExists = typeof Set !== 'undefined'; var weakMapExists = typeof WeakMap !== 'undefined'; var weakSetExists = typeof WeakSet !== 'undefined'; var dataViewExists = typeof DataView !== 'undefined'; var symbolIteratorExists = symbolExists && typeof Symbol.iterator !== 'undefined'; var symbolToStringTagExists = symbolExists && typeof Symbol.toStringTag !== 'undefined'; var setEntriesExists = setExists && typeof Set.prototype.entries === 'function'; var mapEntriesExists = mapExists && typeof Map.prototype.entries === 'function'; var setIteratorPrototype = setEntriesExists && Object.getPrototypeOf(new Set().entries()); var mapIteratorPrototype = mapEntriesExists && Object.getPrototypeOf(new Map().entries()); var arrayIteratorExists = symbolIteratorExists && typeof Array.prototype === 'function'; var arrayIteratorPrototype = arrayIteratorExists && Object.getPrototypeOf([]()); var stringIteratorExists = symbolIteratorExists && typeof String.prototype === 'function'; var stringIteratorPrototype = stringIteratorExists && Object.getPrototypeOf(”()); var toStringLeftSliceLength = 8; var toStringRightSliceLength = -1; /**

* ### typeOf (obj)
*
* Uses `Object.prototype.toString` to determine the type of an object,
* normalising behaviour across engine versions & well optimised.
*
* @param {Mixed} object
* @return {String} object type
* @api public
*/

function typeDetect(obj) {

/* ! Speed optimisation
 * Pre:
 *   string literal     x 3,039,035 ops/sec ±1.62% (78 runs sampled)
 *   boolean literal    x 1,424,138 ops/sec ±4.54% (75 runs sampled)
 *   number literal     x 1,653,153 ops/sec ±1.91% (82 runs sampled)
 *   undefined          x 9,978,660 ops/sec ±1.92% (75 runs sampled)
 *   function           x 2,556,769 ops/sec ±1.73% (77 runs sampled)
 * Post:
 *   string literal     x 38,564,796 ops/sec ±1.15% (79 runs sampled)
 *   boolean literal    x 31,148,940 ops/sec ±1.10% (79 runs sampled)
 *   number literal     x 32,679,330 ops/sec ±1.90% (78 runs sampled)
 *   undefined          x 32,363,368 ops/sec ±1.07% (82 runs sampled)
 *   function           x 31,296,870 ops/sec ±0.96% (83 runs sampled)
 */
var typeofObj = typeof obj;
if (typeofObj !== 'object') {
  return typeofObj;
}

/* ! Speed optimisation
 * Pre:
 *   null               x 28,645,765 ops/sec ±1.17% (82 runs sampled)
 * Post:
 *   null               x 36,428,962 ops/sec ±1.37% (84 runs sampled)
 */
if (obj === null) {
  return 'null';
}

/* ! Spec Conformance
 * Test: `Object.prototype.toString.call(window)``
 *  - Node === "[object global]"
 *  - Chrome === "[object global]"
 *  - Firefox === "[object Window]"
 *  - PhantomJS === "[object Window]"
 *  - Safari === "[object Window]"
 *  - IE 11 === "[object Window]"
 *  - IE Edge === "[object Window]"
 * Test: `Object.prototype.toString.call(this)``
 *  - Chrome Worker === "[object global]"
 *  - Firefox Worker === "[object DedicatedWorkerGlobalScope]"
 *  - Safari Worker === "[object DedicatedWorkerGlobalScope]"
 *  - IE 11 Worker === "[object WorkerGlobalScope]"
 *  - IE Edge Worker === "[object WorkerGlobalScope]"
 */
if (obj === globalObject) {
  return 'global';
}

/* ! Speed optimisation
 * Pre:
 *   array literal      x 2,888,352 ops/sec ±0.67% (82 runs sampled)
 * Post:
 *   array literal      x 22,479,650 ops/sec ±0.96% (81 runs sampled)
 */
if (
  Array.isArray(obj) &&
  (symbolToStringTagExists === false || !(Symbol.toStringTag in obj))
) {
  return 'Array';
}

// Not caching existence of `window` and related properties due to potential
// for `window` to be unset before tests in quasi-browser environments.
if (typeof window === 'object' && window !== null) {
  /* ! Spec Conformance
   * (https://html.spec.whatwg.org/multipage/browsers.html#location)
   * WhatWG HTML$7.7.3 - The `Location` interface
   * Test: `Object.prototype.toString.call(window.location)``
   *  - IE <=11 === "[object Object]"
   *  - IE Edge <=13 === "[object Object]"
   */
  if (typeof window.location === 'object' && obj === window.location) {
    return 'Location';
  }

  /* ! Spec Conformance
   * (https://html.spec.whatwg.org/#document)
   * WhatWG HTML$3.1.1 - The `Document` object
   * Note: Most browsers currently adher to the W3C DOM Level 2 spec
   *       (https://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-26809268)
   *       which suggests that browsers should use HTMLTableCellElement for
   *       both TD and TH elements. WhatWG separates these.
   *       WhatWG HTML states:
   *         > For historical reasons, Window objects must also have a
   *         > writable, configurable, non-enumerable property named
   *         > HTMLDocument whose value is the Document interface object.
   * Test: `Object.prototype.toString.call(document)``
   *  - Chrome === "[object HTMLDocument]"
   *  - Firefox === "[object HTMLDocument]"
   *  - Safari === "[object HTMLDocument]"
   *  - IE <=10 === "[object Document]"
   *  - IE 11 === "[object HTMLDocument]"
   *  - IE Edge <=13 === "[object HTMLDocument]"
   */
  if (typeof window.document === 'object' && obj === window.document) {
    return 'Document';
  }

  if (typeof window.navigator === 'object') {
    /* ! Spec Conformance
     * (https://html.spec.whatwg.org/multipage/webappapis.html#mimetypearray)
     * WhatWG HTML$8.6.1.5 - Plugins - Interface MimeTypeArray
     * Test: `Object.prototype.toString.call(navigator.mimeTypes)``
     *  - IE <=10 === "[object MSMimeTypesCollection]"
     */
    if (typeof window.navigator.mimeTypes === 'object' &&
        obj === window.navigator.mimeTypes) {
      return 'MimeTypeArray';
    }

    /* ! Spec Conformance
     * (https://html.spec.whatwg.org/multipage/webappapis.html#pluginarray)
     * WhatWG HTML$8.6.1.5 - Plugins - Interface PluginArray
     * Test: `Object.prototype.toString.call(navigator.plugins)``
     *  - IE <=10 === "[object MSPluginsCollection]"
     */
    if (typeof window.navigator.plugins === 'object' &&
        obj === window.navigator.plugins) {
      return 'PluginArray';
    }
  }

  if ((typeof window.HTMLElement === 'function' ||
      typeof window.HTMLElement === 'object') &&
      obj instanceof window.HTMLElement) {
    /* ! Spec Conformance
    * (https://html.spec.whatwg.org/multipage/webappapis.html#pluginarray)
    * WhatWG HTML$4.4.4 - The `blockquote` element - Interface `HTMLQuoteElement`
    * Test: `Object.prototype.toString.call(document.createElement('blockquote'))``
    *  - IE <=10 === "[object HTMLBlockElement]"
    */
    if (obj.tagName === 'BLOCKQUOTE') {
      return 'HTMLQuoteElement';
    }

    /* ! Spec Conformance
     * (https://html.spec.whatwg.org/#htmltabledatacellelement)
     * WhatWG HTML$4.9.9 - The `td` element - Interface `HTMLTableDataCellElement`
     * Note: Most browsers currently adher to the W3C DOM Level 2 spec
     *       (https://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-82915075)
     *       which suggests that browsers should use HTMLTableCellElement for
     *       both TD and TH elements. WhatWG separates these.
     * Test: Object.prototype.toString.call(document.createElement('td'))
     *  - Chrome === "[object HTMLTableCellElement]"
     *  - Firefox === "[object HTMLTableCellElement]"
     *  - Safari === "[object HTMLTableCellElement]"
     */
    if (obj.tagName === 'TD') {
      return 'HTMLTableDataCellElement';
    }

    /* ! Spec Conformance
     * (https://html.spec.whatwg.org/#htmltableheadercellelement)
     * WhatWG HTML$4.9.9 - The `td` element - Interface `HTMLTableHeaderCellElement`
     * Note: Most browsers currently adher to the W3C DOM Level 2 spec
     *       (https://www.w3.org/TR/DOM-Level-2-HTML/html.html#ID-82915075)
     *       which suggests that browsers should use HTMLTableCellElement for
     *       both TD and TH elements. WhatWG separates these.
     * Test: Object.prototype.toString.call(document.createElement('th'))
     *  - Chrome === "[object HTMLTableCellElement]"
     *  - Firefox === "[object HTMLTableCellElement]"
     *  - Safari === "[object HTMLTableCellElement]"
     */
    if (obj.tagName === 'TH') {
      return 'HTMLTableHeaderCellElement';
    }
  }
}

/* ! Speed optimisation
* Pre:
*   Float64Array       x 625,644 ops/sec ±1.58% (80 runs sampled)
*   Float32Array       x 1,279,852 ops/sec ±2.91% (77 runs sampled)
*   Uint32Array        x 1,178,185 ops/sec ±1.95% (83 runs sampled)
*   Uint16Array        x 1,008,380 ops/sec ±2.25% (80 runs sampled)
*   Uint8Array         x 1,128,040 ops/sec ±2.11% (81 runs sampled)
*   Int32Array         x 1,170,119 ops/sec ±2.88% (80 runs sampled)
*   Int16Array         x 1,176,348 ops/sec ±5.79% (86 runs sampled)
*   Int8Array          x 1,058,707 ops/sec ±4.94% (77 runs sampled)
*   Uint8ClampedArray  x 1,110,633 ops/sec ±4.20% (80 runs sampled)
* Post:
*   Float64Array       x 7,105,671 ops/sec ±13.47% (64 runs sampled)
*   Float32Array       x 5,887,912 ops/sec ±1.46% (82 runs sampled)
*   Uint32Array        x 6,491,661 ops/sec ±1.76% (79 runs sampled)
*   Uint16Array        x 6,559,795 ops/sec ±1.67% (82 runs sampled)
*   Uint8Array         x 6,463,966 ops/sec ±1.43% (85 runs sampled)
*   Int32Array         x 5,641,841 ops/sec ±3.49% (81 runs sampled)
*   Int16Array         x 6,583,511 ops/sec ±1.98% (80 runs sampled)
*   Int8Array          x 6,606,078 ops/sec ±1.74% (81 runs sampled)
*   Uint8ClampedArray  x 6,602,224 ops/sec ±1.77% (83 runs sampled)
*/
var stringTag = (symbolToStringTagExists && obj[Symbol.toStringTag]);
if (typeof stringTag === 'string') {
  return stringTag;
}

var objPrototype = Object.getPrototypeOf(obj);
/* ! Speed optimisation
* Pre:
*   regex literal      x 1,772,385 ops/sec ±1.85% (77 runs sampled)
*   regex constructor  x 2,143,634 ops/sec ±2.46% (78 runs sampled)
* Post:
*   regex literal      x 3,928,009 ops/sec ±0.65% (78 runs sampled)
*   regex constructor  x 3,931,108 ops/sec ±0.58% (84 runs sampled)
*/
if (objPrototype === RegExp.prototype) {
  return 'RegExp';
}

/* ! Speed optimisation
* Pre:
*   date               x 2,130,074 ops/sec ±4.42% (68 runs sampled)
* Post:
*   date               x 3,953,779 ops/sec ±1.35% (77 runs sampled)
*/
if (objPrototype === Date.prototype) {
  return 'Date';
}

/* ! Spec Conformance
 * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-promise.prototype-@@tostringtag)
 * ES6$25.4.5.4 - Promise.prototype[@@toStringTag] should be "Promise":
 * Test: `Object.prototype.toString.call(Promise.resolve())``
 *  - Chrome <=47 === "[object Object]"
 *  - Edge <=20 === "[object Object]"
 *  - Firefox 29-Latest === "[object Promise]"
 *  - Safari 7.1-Latest === "[object Promise]"
 */
if (promiseExists && objPrototype === Promise.prototype) {
  return 'Promise';
}

/* ! Speed optimisation
* Pre:
*   set                x 2,222,186 ops/sec ±1.31% (82 runs sampled)
* Post:
*   set                x 4,545,879 ops/sec ±1.13% (83 runs sampled)
*/
if (setExists && objPrototype === Set.prototype) {
  return 'Set';
}

/* ! Speed optimisation
* Pre:
*   map                x 2,396,842 ops/sec ±1.59% (81 runs sampled)
* Post:
*   map                x 4,183,945 ops/sec ±6.59% (82 runs sampled)
*/
if (mapExists && objPrototype === Map.prototype) {
  return 'Map';
}

/* ! Speed optimisation
* Pre:
*   weakset            x 1,323,220 ops/sec ±2.17% (76 runs sampled)
* Post:
*   weakset            x 4,237,510 ops/sec ±2.01% (77 runs sampled)
*/
if (weakSetExists && objPrototype === WeakSet.prototype) {
  return 'WeakSet';
}

/* ! Speed optimisation
* Pre:
*   weakmap            x 1,500,260 ops/sec ±2.02% (78 runs sampled)
* Post:
*   weakmap            x 3,881,384 ops/sec ±1.45% (82 runs sampled)
*/
if (weakMapExists && objPrototype === WeakMap.prototype) {
  return 'WeakMap';
}

/* ! Spec Conformance
 * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-dataview.prototype-@@tostringtag)
 * ES6$24.2.4.21 - DataView.prototype[@@toStringTag] should be "DataView":
 * Test: `Object.prototype.toString.call(new DataView(new ArrayBuffer(1)))``
 *  - Edge <=13 === "[object Object]"
 */
if (dataViewExists && objPrototype === DataView.prototype) {
  return 'DataView';
}

/* ! Spec Conformance
 * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-%mapiteratorprototype%-@@tostringtag)
 * ES6$23.1.5.2.2 - %MapIteratorPrototype%[@@toStringTag] should be "Map Iterator":
 * Test: `Object.prototype.toString.call(new Map().entries())``
 *  - Edge <=13 === "[object Object]"
 */
if (mapExists && objPrototype === mapIteratorPrototype) {
  return 'Map Iterator';
}

/* ! Spec Conformance
 * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-%setiteratorprototype%-@@tostringtag)
 * ES6$23.2.5.2.2 - %SetIteratorPrototype%[@@toStringTag] should be "Set Iterator":
 * Test: `Object.prototype.toString.call(new Set().entries())``
 *  - Edge <=13 === "[object Object]"
 */
if (setExists && objPrototype === setIteratorPrototype) {
  return 'Set Iterator';
}

/* ! Spec Conformance
 * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-%arrayiteratorprototype%-@@tostringtag)
 * ES6$22.1.5.2.2 - %ArrayIteratorPrototype%[@@toStringTag] should be "Array Iterator":
 * Test: `Object.prototype.toString.call([][Symbol.iterator]())``
 *  - Edge <=13 === "[object Object]"
 */
if (arrayIteratorExists && objPrototype === arrayIteratorPrototype) {
  return 'Array Iterator';
}

/* ! Spec Conformance
 * (http://www.ecma-international.org/ecma-262/6.0/index.html#sec-%stringiteratorprototype%-@@tostringtag)
 * ES6$21.1.5.2.2 - %StringIteratorPrototype%[@@toStringTag] should be "String Iterator":
 * Test: `Object.prototype.toString.call(''[Symbol.iterator]())``
 *  - Edge <=13 === "[object Object]"
 */
if (stringIteratorExists && objPrototype === stringIteratorPrototype) {
  return 'String Iterator';
}

/* ! Speed optimisation
* Pre:
*   object from null   x 2,424,320 ops/sec ±1.67% (76 runs sampled)
* Post:
*   object from null   x 5,838,000 ops/sec ±0.99% (84 runs sampled)
*/
if (objPrototype === null) {
  return 'Object';
}

return Object
  .prototype
  .toString
  .call(obj)
  .slice(toStringLeftSliceLength, toStringRightSliceLength);

}

return typeDetect;

})));

},{}]},{},[1])(1) });