/*

* verror.js: richer JavaScript errors
*/

var mod_assertplus = require('assert-plus'); var mod_util = require('util');

var mod_extsprintf = require('extsprintf'); var mod_isError = require('core-util-is').isError; var sprintf = mod_extsprintf.sprintf;

/*

* Public interface
*/

/* So you can 'var VError = require('verror')' */ module.exports = VError; /* For compatibility */ VError.VError = VError; /* Other exported classes */ VError.SError = SError; VError.WError = WError; VError.MultiError = MultiError;

/*

* Common function used to parse constructor arguments for VError, WError, and
* SError.  Named arguments to this function:
*
*     strict           force strict interpretation of sprintf arguments, even
*                      if the options in "argv" don't say so
*
*     argv             error's constructor arguments, which are to be
*                      interpreted as described in README.md.  For quick
*                      reference, "argv" has one of the following forms:
*
*          [ sprintf_args... ]           (argv[0] is a string)
*          [ cause, sprintf_args... ]    (argv[0] is an Error)
*          [ options, sprintf_args... ]  (argv[0] is an object)
*
* This function normalizes these forms, producing an object with the following
* properties:
*
*    options           equivalent to "options" in third form.  This will never
*                      be a direct reference to what the caller passed in
*                      (i.e., it may be a shallow copy), so it can be freely
*                      modified.
*
*    shortmessage      result of sprintf(sprintf_args), taking options.strict
*                      into account as described in README.md.
*/

function parseConstructorArguments(args) {

var argv, options, sprintf_args, shortmessage, k;

mod_assertplus.object(args, 'args');
mod_assertplus.bool(args.strict, 'args.strict');
mod_assertplus.array(args.argv, 'args.argv');
argv = args.argv;

/*
 * First, figure out which form of invocation we've been given.
 */
if (argv.length === 0) {
        options = {};
        sprintf_args = [];
} else if (mod_isError(argv[0])) {
        options = { 'cause': argv[0] };
        sprintf_args = argv.slice(1);
} else if (typeof (argv[0]) === 'object') {
        options = {};
        for (k in argv[0]) {
                options[k] = argv[0][k];
        }
        sprintf_args = argv.slice(1);
} else {
        mod_assertplus.string(argv[0],
            'first argument to VError, SError, or WError ' +
            'constructor must be a string, object, or Error');
        options = {};
        sprintf_args = argv;
}

/*
 * Now construct the error's message.
 *
 * extsprintf (which we invoke here with our caller's arguments in order
 * to construct this Error's message) is strict in its interpretation of
 * values to be processed by the "%s" specifier.  The value passed to
 * extsprintf must actually be a string or something convertible to a
 * String using .toString().  Passing other values (notably "null" and
 * "undefined") is considered a programmer error.  The assumption is
 * that if you actually want to print the string "null" or "undefined",
 * then that's easy to do that when you're calling extsprintf; on the
 * other hand, if you did NOT want that (i.e., there's actually a bug
 * where the program assumes some variable is non-null and tries to
 * print it, which might happen when constructing a packet or file in
 * some specific format), then it's better to stop immediately than
 * produce bogus output.
 *
 * However, sometimes the bug is only in the code calling VError, and a
 * programmer might prefer to have the error message contain "null" or
 * "undefined" rather than have the bug in the error path crash the
 * program (making the first bug harder to identify).  For that reason,
 * by default VError converts "null" or "undefined" arguments to their
 * string representations and passes those to extsprintf.  Programmers
 * desiring the strict behavior can use the SError class or pass the
 * "strict" option to the VError constructor.
 */
mod_assertplus.object(options);
if (!options.strict && !args.strict) {
        sprintf_args = sprintf_args.map(function (a) {
                return (a === null ? 'null' :
                    a === undefined ? 'undefined' : a);
        });
}

if (sprintf_args.length === 0) {
        shortmessage = '';
} else {
        shortmessage = sprintf.apply(null, sprintf_args);
}

return ({
    'options': options,
    'shortmessage': shortmessage
});

}

/*

* See README.md for reference documentation.
*/

function VError() {

var args, obj, parsed, cause, ctor, message, k;

args = Array.prototype.slice.call(arguments, 0);

/*
 * This is a regrettable pattern, but JavaScript's built-in Error class
 * is defined to work this way, so we allow the constructor to be called
 * without "new".
 */
if (!(this instanceof VError)) {
        obj = Object.create(VError.prototype);
        VError.apply(obj, arguments);
        return (obj);
}

/*
 * For convenience and backwards compatibility, we support several
 * different calling forms.  Normalize them here.
 */
parsed = parseConstructorArguments({
    'argv': args,
    'strict': false
});

/*
 * If we've been given a name, apply it now.
 */
if (parsed.options.name) {
        mod_assertplus.string(parsed.options.name,
            'error\'s "name" must be a string');
        this.name = parsed.options.name;
}

/*
 * For debugging, we keep track of the original short message (attached
 * this Error particularly) separately from the complete message (which
 * includes the messages of our cause chain).
 */
this.jse_shortmsg = parsed.shortmessage;
message = parsed.shortmessage;

/*
 * If we've been given a cause, record a reference to it and update our
 * message appropriately.
 */
cause = parsed.options.cause;
if (cause) {
        mod_assertplus.ok(mod_isError(cause), 'cause is not an Error');
        this.jse_cause = cause;

        if (!parsed.options.skipCauseMessage) {
                message += ': ' + cause.message;
        }
}

/*
 * If we've been given an object with properties, shallow-copy that
 * here.  We don't want to use a deep copy in case there are non-plain
 * objects here, but we don't want to use the original object in case
 * the caller modifies it later.
 */
this.jse_info = {};
if (parsed.options.info) {
        for (k in parsed.options.info) {
                this.jse_info[k] = parsed.options.info[k];
        }
}

this.message = message;
Error.call(this, message);

if (Error.captureStackTrace) {
        ctor = parsed.options.constructorOpt || this.constructor;
        Error.captureStackTrace(this, ctor);
}

return (this);

}

mod_util.inherits(VError, Error); VError.prototype.name = 'VError';

VError.prototype.toString = function ve_toString() {

var str = (this.hasOwnProperty('name') && this.name ||
        this.constructor.name || this.constructor.prototype.name);
if (this.message)
        str += ': ' + this.message;

return (str);

};

/*

* This method is provided for compatibility.  New callers should use
* VError.cause() instead.  That method also uses the saner `null` return value
* when there is no cause.
*/

VError.prototype.cause = function ve_cause() {

var cause = VError.cause(this);
return (cause === null ? undefined : cause);

};

/*

* Static methods
*
* These class-level methods are provided so that callers can use them on
* instances of Errors that are not VErrors.  New interfaces should be provided
* only using static methods to eliminate the class of programming mistake where
* people fail to check whether the Error object has the corresponding methods.
*/

VError.cause = function (err) {

mod_assertplus.ok(mod_isError(err), 'err must be an Error');
return (mod_isError(err.jse_cause) ? err.jse_cause : null);

};

VError.info = function (err) {

var rv, cause, k;

mod_assertplus.ok(mod_isError(err), 'err must be an Error');
cause = VError.cause(err);
if (cause !== null) {
        rv = VError.info(cause);
} else {
        rv = {};
}

if (typeof (err.jse_info) == 'object' && err.jse_info !== null) {
        for (k in err.jse_info) {
                rv[k] = err.jse_info[k];
        }
}

return (rv);

};

VError.findCauseByName = function (err, name) {

var cause;

mod_assertplus.ok(mod_isError(err), 'err must be an Error');
mod_assertplus.string(name, 'name');
mod_assertplus.ok(name.length > 0, 'name cannot be empty');

for (cause = err; cause !== null; cause = VError.cause(cause)) {
        mod_assertplus.ok(mod_isError(cause));
        if (cause.name == name) {
                return (cause);
        }
}

return (null);

};

VError.hasCauseWithName = function (err, name) {

return (VError.findCauseByName(err, name) !== null);

};

VError.fullStack = function (err) {

mod_assertplus.ok(mod_isError(err), 'err must be an Error');

var cause = VError.cause(err);

if (cause) {
        return (err.stack + '\ncaused by: ' + VError.fullStack(cause));
}

return (err.stack);

};

VError.errorFromList = function (errors) {

mod_assertplus.arrayOfObject(errors, 'errors');

if (errors.length === 0) {
        return (null);
}

errors.forEach(function (e) {
        mod_assertplus.ok(mod_isError(e));
});

if (errors.length == 1) {
        return (errors[0]);
}

return (new MultiError(errors));

};

VError.errorForEach = function (err, func) {

mod_assertplus.ok(mod_isError(err), 'err must be an Error');
mod_assertplus.func(func, 'func');

if (err instanceof MultiError) {
        err.errors().forEach(function iterError(e) { func(e); });
} else {
        func(err);
}

};

/*

* SError is like VError, but stricter about types.  You cannot pass "null" or
* "undefined" as string arguments to the formatter.
*/

function SError() {

var args, obj, parsed, options;

args = Array.prototype.slice.call(arguments, 0);
if (!(this instanceof SError)) {
        obj = Object.create(SError.prototype);
        SError.apply(obj, arguments);
        return (obj);
}

parsed = parseConstructorArguments({
    'argv': args,
    'strict': true
});

options = parsed.options;
VError.call(this, options, '%s', parsed.shortmessage);

return (this);

}

/*

* We don't bother setting SError.prototype.name because once constructed,
* SErrors are just like VErrors.
*/

mod_util.inherits(SError, VError);

/*

* Represents a collection of errors for the purpose of consumers that generally
* only deal with one error.  Callers can extract the individual errors
* contained in this object, but may also just treat it as a normal single
* error, in which case a summary message will be printed.
*/

function MultiError(errors) {

mod_assertplus.array(errors, 'list of errors');
mod_assertplus.ok(errors.length > 0, 'must be at least one error');
this.ase_errors = errors;

VError.call(this, {
    'cause': errors[0]
}, 'first of %d error%s', errors.length, errors.length == 1 ? '' : 's');

}

mod_util.inherits(MultiError, VError); MultiError.prototype.name = 'MultiError';

MultiError.prototype.errors = function me_errors() {

return (this.ase_errors.slice(0));

};

/*

* See README.md for reference details.
*/

function WError() {

var args, obj, parsed, options;

args = Array.prototype.slice.call(arguments, 0);
if (!(this instanceof WError)) {
        obj = Object.create(WError.prototype);
        WError.apply(obj, args);
        return (obj);
}

parsed = parseConstructorArguments({
    'argv': args,
    'strict': false
});

options = parsed.options;
options['skipCauseMessage'] = true;
VError.call(this, options, '%s', parsed.shortmessage);

return (this);

}

mod_util.inherits(WError, VError); WError.prototype.name = 'WError';

WError.prototype.toString = function we_toString() {

var str = (this.hasOwnProperty('name') && this.name ||
        this.constructor.name || this.constructor.prototype.name);
if (this.message)
        str += ': ' + this.message;
if (this.jse_cause && this.jse_cause.message)
        str += '; caused by ' + this.jse_cause.toString();

return (str);

};

/*

* For purely historical reasons, WError's cause() function allows you to set
* the cause.
*/

WError.prototype.cause = function we_cause© {

if (mod_isError(c))
        this.jse_cause = c;

return (this.jse_cause);

};