// jscs:disable requireUseStrict

var test = require('tape');

var functionBind = require('../implementation'); var getCurrentContext = function () { return this; };

test('functionBind is a function', function (t) {

t.equal(typeof functionBind, 'function');
t.end();

});

test('non-functions', function (t) {

var nonFunctions = [true, false, [], {}, 42, 'foo', NaN, /a/g];
t.plan(nonFunctions.length);
for (var i = 0; i < nonFunctions.length; ++i) {
    try { functionBind.call(nonFunctions[i]); } catch (ex) {
        t.ok(ex instanceof TypeError, 'throws when given ' + String(nonFunctions[i]));
    }
}
t.end();

});

test('without a context', function (t) {

t.test('binds properly', function (st) {
    var args, context;
    var namespace = {
        func: functionBind.call(function () {
            args = Array.prototype.slice.call(arguments);
            context = this;
        })
    };
    namespace.func(1, 2, 3);
    st.deepEqual(args, [1, 2, 3]);
    st.equal(context, getCurrentContext.call());
    st.end();
});

t.test('binds properly, and still supplies bound arguments', function (st) {
    var args, context;
    var namespace = {
        func: functionBind.call(function () {
            args = Array.prototype.slice.call(arguments);
            context = this;
        }, undefined, 1, 2, 3)
    };
    namespace.func(4, 5, 6);
    st.deepEqual(args, [1, 2, 3, 4, 5, 6]);
    st.equal(context, getCurrentContext.call());
    st.end();
});

t.test('returns properly', function (st) {
    var args;
    var namespace = {
        func: functionBind.call(function () {
            args = Array.prototype.slice.call(arguments);
            return this;
        }, null)
    };
    var context = namespace.func(1, 2, 3);
    st.equal(context, getCurrentContext.call(), 'returned context is namespaced context');
    st.deepEqual(args, [1, 2, 3], 'passed arguments are correct');
    st.end();
});

t.test('returns properly with bound arguments', function (st) {
    var args;
    var namespace = {
        func: functionBind.call(function () {
            args = Array.prototype.slice.call(arguments);
            return this;
        }, null, 1, 2, 3)
    };
    var context = namespace.func(4, 5, 6);
    st.equal(context, getCurrentContext.call(), 'returned context is namespaced context');
    st.deepEqual(args, [1, 2, 3, 4, 5, 6], 'passed arguments are correct');
    st.end();
});

t.test('called as a constructor', function (st) {
    var thunkify = function (value) {
        return function () { return value; };
    };
    st.test('returns object value', function (sst) {
        var expectedReturnValue = [1, 2, 3];
        var Constructor = functionBind.call(thunkify(expectedReturnValue), null);
        var result = new Constructor();
        sst.equal(result, expectedReturnValue);
        sst.end();
    });

    st.test('does not return primitive value', function (sst) {
        var Constructor = functionBind.call(thunkify(42), null);
        var result = new Constructor();
        sst.notEqual(result, 42);
        sst.end();
    });

    st.test('object from bound constructor is instance of original and bound constructor', function (sst) {
        var A = function (x) {
            this.name = x || 'A';
        };
        var B = functionBind.call(A, null, 'B');

        var result = new B();
        sst.ok(result instanceof B, 'result is instance of bound constructor');
        sst.ok(result instanceof A, 'result is instance of original constructor');
        sst.end();
    });

    st.end();
});

t.end();

});

test('with a context', function (t) {

t.test('with no bound arguments', function (st) {
    var args, context;
    var boundContext = {};
    var namespace = {
        func: functionBind.call(function () {
            args = Array.prototype.slice.call(arguments);
            context = this;
        }, boundContext)
    };
    namespace.func(1, 2, 3);
    st.equal(context, boundContext, 'binds a context properly');
    st.deepEqual(args, [1, 2, 3], 'supplies passed arguments');
    st.end();
});

t.test('with bound arguments', function (st) {
    var args, context;
    var boundContext = {};
    var namespace = {
        func: functionBind.call(function () {
            args = Array.prototype.slice.call(arguments);
            context = this;
        }, boundContext, 1, 2, 3)
    };
    namespace.func(4, 5, 6);
    st.equal(context, boundContext, 'binds a context properly');
    st.deepEqual(args, [1, 2, 3, 4, 5, 6], 'supplies bound and passed arguments');
    st.end();
});

t.test('returns properly', function (st) {
    var boundContext = {};
    var args;
    var namespace = {
        func: functionBind.call(function () {
            args = Array.prototype.slice.call(arguments);
            return this;
        }, boundContext)
    };
    var context = namespace.func(1, 2, 3);
    st.equal(context, boundContext, 'returned context is bound context');
    st.notEqual(context, getCurrentContext.call(), 'returned context is not lexical context');
    st.deepEqual(args, [1, 2, 3], 'passed arguments are correct');
    st.end();
});

t.test('returns properly with bound arguments', function (st) {
    var boundContext = {};
    var args;
    var namespace = {
        func: functionBind.call(function () {
            args = Array.prototype.slice.call(arguments);
            return this;
        }, boundContext, 1, 2, 3)
    };
    var context = namespace.func(4, 5, 6);
    st.equal(context, boundContext, 'returned context is bound context');
    st.notEqual(context, getCurrentContext.call(), 'returned context is not lexical context');
    st.deepEqual(args, [1, 2, 3, 4, 5, 6], 'passed arguments are correct');
    st.end();
});

t.test('passes the correct arguments when called as a constructor', function (st) {
    var expected = { name: 'Correct' };
    var namespace = {
        Func: functionBind.call(function (arg) {
            return arg;
        }, { name: 'Incorrect' })
    };
    var returned = new namespace.Func(expected);
    st.equal(returned, expected, 'returns the right arg when called as a constructor');
    st.end();
});

t.test('has the new instance\'s context when called as a constructor', function (st) {
    var actualContext;
    var expectedContext = { foo: 'bar' };
    var namespace = {
        Func: functionBind.call(function () {
            actualContext = this;
        }, expectedContext)
    };
    var result = new namespace.Func();
    st.equal(result instanceof namespace.Func, true);
    st.notEqual(actualContext, expectedContext);
    st.end();
});

t.end();

});

test('bound function length', function (t) {

t.test('sets a correct length without thisArg', function (st) {
    var subject = functionBind.call(function (a, b, c) { return a + b + c; });
    st.equal(subject.length, 3);
    st.equal(subject(1, 2, 3), 6);
    st.end();
});

t.test('sets a correct length with thisArg', function (st) {
    var subject = functionBind.call(function (a, b, c) { return a + b + c; }, {});
    st.equal(subject.length, 3);
    st.equal(subject(1, 2, 3), 6);
    st.end();
});

t.test('sets a correct length without thisArg and first argument', function (st) {
    var subject = functionBind.call(function (a, b, c) { return a + b + c; }, undefined, 1);
    st.equal(subject.length, 2);
    st.equal(subject(2, 3), 6);
    st.end();
});

t.test('sets a correct length with thisArg and first argument', function (st) {
    var subject = functionBind.call(function (a, b, c) { return a + b + c; }, {}, 1);
    st.equal(subject.length, 2);
    st.equal(subject(2, 3), 6);
    st.end();
});

t.test('sets a correct length without thisArg and too many arguments', function (st) {
    var subject = functionBind.call(function (a, b, c) { return a + b + c; }, undefined, 1, 2, 3, 4);
    st.equal(subject.length, 0);
    st.equal(subject(), 6);
    st.end();
});

t.test('sets a correct length with thisArg and too many arguments', function (st) {
    var subject = functionBind.call(function (a, b, c) { return a + b + c; }, {}, 1, 2, 3, 4);
    st.equal(subject.length, 0);
    st.equal(subject(), 6);
    st.end();
});

});