/*
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* verror.js: richer JavaScript errors
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*/
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var mod_assertplus = require('assert-plus');
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var mod_util = require('util');
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var mod_extsprintf = require('extsprintf');
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var mod_isError = require('core-util-is').isError;
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var sprintf = mod_extsprintf.sprintf;
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/*
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* Public interface
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*/
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/* So you can 'var VError = require('verror')' */
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module.exports = VError;
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/* For compatibility */
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VError.VError = VError;
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/* Other exported classes */
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VError.SError = SError;
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VError.WError = WError;
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VError.MultiError = MultiError;
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/*
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* Common function used to parse constructor arguments for VError, WError, and
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* SError. Named arguments to this function:
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*
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* strict force strict interpretation of sprintf arguments, even
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* if the options in "argv" don't say so
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*
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* argv error's constructor arguments, which are to be
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* interpreted as described in README.md. For quick
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* reference, "argv" has one of the following forms:
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*
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* [ sprintf_args... ] (argv[0] is a string)
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* [ cause, sprintf_args... ] (argv[0] is an Error)
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* [ options, sprintf_args... ] (argv[0] is an object)
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*
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* This function normalizes these forms, producing an object with the following
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* properties:
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*
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* options equivalent to "options" in third form. This will never
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* be a direct reference to what the caller passed in
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* (i.e., it may be a shallow copy), so it can be freely
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* modified.
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*
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* shortmessage result of sprintf(sprintf_args), taking options.strict
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* into account as described in README.md.
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*/
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function parseConstructorArguments(args)
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{
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var argv, options, sprintf_args, shortmessage, k;
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mod_assertplus.object(args, 'args');
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mod_assertplus.bool(args.strict, 'args.strict');
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mod_assertplus.array(args.argv, 'args.argv');
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argv = args.argv;
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/*
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* First, figure out which form of invocation we've been given.
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*/
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if (argv.length === 0) {
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options = {};
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sprintf_args = [];
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} else if (mod_isError(argv[0])) {
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options = { 'cause': argv[0] };
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sprintf_args = argv.slice(1);
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} else if (typeof (argv[0]) === 'object') {
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options = {};
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for (k in argv[0]) {
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options[k] = argv[0][k];
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}
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sprintf_args = argv.slice(1);
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} else {
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mod_assertplus.string(argv[0],
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'first argument to VError, SError, or WError ' +
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'constructor must be a string, object, or Error');
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options = {};
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sprintf_args = argv;
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}
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/*
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* Now construct the error's message.
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*
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* extsprintf (which we invoke here with our caller's arguments in order
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* to construct this Error's message) is strict in its interpretation of
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* values to be processed by the "%s" specifier. The value passed to
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* extsprintf must actually be a string or something convertible to a
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* String using .toString(). Passing other values (notably "null" and
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* "undefined") is considered a programmer error. The assumption is
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* that if you actually want to print the string "null" or "undefined",
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* then that's easy to do that when you're calling extsprintf; on the
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* other hand, if you did NOT want that (i.e., there's actually a bug
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* where the program assumes some variable is non-null and tries to
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* print it, which might happen when constructing a packet or file in
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* some specific format), then it's better to stop immediately than
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* produce bogus output.
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*
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* However, sometimes the bug is only in the code calling VError, and a
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* programmer might prefer to have the error message contain "null" or
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* "undefined" rather than have the bug in the error path crash the
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* program (making the first bug harder to identify). For that reason,
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* by default VError converts "null" or "undefined" arguments to their
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* string representations and passes those to extsprintf. Programmers
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* desiring the strict behavior can use the SError class or pass the
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* "strict" option to the VError constructor.
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*/
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mod_assertplus.object(options);
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if (!options.strict && !args.strict) {
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sprintf_args = sprintf_args.map(function (a) {
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return (a === null ? 'null' :
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a === undefined ? 'undefined' : a);
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});
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}
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if (sprintf_args.length === 0) {
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shortmessage = '';
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} else {
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shortmessage = sprintf.apply(null, sprintf_args);
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}
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return ({
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'options': options,
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'shortmessage': shortmessage
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});
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}
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/*
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* See README.md for reference documentation.
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*/
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function VError()
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{
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var args, obj, parsed, cause, ctor, message, k;
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args = Array.prototype.slice.call(arguments, 0);
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/*
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* This is a regrettable pattern, but JavaScript's built-in Error class
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* is defined to work this way, so we allow the constructor to be called
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* without "new".
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*/
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if (!(this instanceof VError)) {
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obj = Object.create(VError.prototype);
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VError.apply(obj, arguments);
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return (obj);
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}
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/*
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* For convenience and backwards compatibility, we support several
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* different calling forms. Normalize them here.
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*/
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parsed = parseConstructorArguments({
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'argv': args,
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'strict': false
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});
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/*
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* If we've been given a name, apply it now.
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*/
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if (parsed.options.name) {
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mod_assertplus.string(parsed.options.name,
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'error\'s "name" must be a string');
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this.name = parsed.options.name;
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}
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/*
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* For debugging, we keep track of the original short message (attached
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* this Error particularly) separately from the complete message (which
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* includes the messages of our cause chain).
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*/
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this.jse_shortmsg = parsed.shortmessage;
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message = parsed.shortmessage;
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/*
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* If we've been given a cause, record a reference to it and update our
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* message appropriately.
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*/
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cause = parsed.options.cause;
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if (cause) {
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mod_assertplus.ok(mod_isError(cause), 'cause is not an Error');
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this.jse_cause = cause;
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if (!parsed.options.skipCauseMessage) {
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message += ': ' + cause.message;
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}
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}
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/*
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* If we've been given an object with properties, shallow-copy that
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* here. We don't want to use a deep copy in case there are non-plain
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* objects here, but we don't want to use the original object in case
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* the caller modifies it later.
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*/
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this.jse_info = {};
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if (parsed.options.info) {
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for (k in parsed.options.info) {
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this.jse_info[k] = parsed.options.info[k];
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}
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}
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this.message = message;
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Error.call(this, message);
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if (Error.captureStackTrace) {
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ctor = parsed.options.constructorOpt || this.constructor;
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Error.captureStackTrace(this, ctor);
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}
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return (this);
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}
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mod_util.inherits(VError, Error);
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VError.prototype.name = 'VError';
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VError.prototype.toString = function ve_toString()
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{
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var str = (this.hasOwnProperty('name') && this.name ||
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this.constructor.name || this.constructor.prototype.name);
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if (this.message)
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str += ': ' + this.message;
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return (str);
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};
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/*
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* This method is provided for compatibility. New callers should use
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* VError.cause() instead. That method also uses the saner `null` return value
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* when there is no cause.
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*/
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VError.prototype.cause = function ve_cause()
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{
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var cause = VError.cause(this);
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return (cause === null ? undefined : cause);
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};
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/*
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* Static methods
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*
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* These class-level methods are provided so that callers can use them on
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* instances of Errors that are not VErrors. New interfaces should be provided
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* only using static methods to eliminate the class of programming mistake where
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* people fail to check whether the Error object has the corresponding methods.
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*/
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VError.cause = function (err)
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{
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mod_assertplus.ok(mod_isError(err), 'err must be an Error');
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return (mod_isError(err.jse_cause) ? err.jse_cause : null);
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};
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VError.info = function (err)
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{
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var rv, cause, k;
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mod_assertplus.ok(mod_isError(err), 'err must be an Error');
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cause = VError.cause(err);
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if (cause !== null) {
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rv = VError.info(cause);
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} else {
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rv = {};
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}
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if (typeof (err.jse_info) == 'object' && err.jse_info !== null) {
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for (k in err.jse_info) {
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rv[k] = err.jse_info[k];
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}
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}
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return (rv);
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};
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VError.findCauseByName = function (err, name)
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{
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var cause;
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mod_assertplus.ok(mod_isError(err), 'err must be an Error');
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mod_assertplus.string(name, 'name');
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mod_assertplus.ok(name.length > 0, 'name cannot be empty');
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for (cause = err; cause !== null; cause = VError.cause(cause)) {
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mod_assertplus.ok(mod_isError(cause));
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if (cause.name == name) {
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return (cause);
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}
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}
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return (null);
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};
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VError.hasCauseWithName = function (err, name)
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{
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return (VError.findCauseByName(err, name) !== null);
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};
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VError.fullStack = function (err)
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{
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mod_assertplus.ok(mod_isError(err), 'err must be an Error');
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var cause = VError.cause(err);
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if (cause) {
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return (err.stack + '\ncaused by: ' + VError.fullStack(cause));
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}
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return (err.stack);
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};
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VError.errorFromList = function (errors)
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{
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mod_assertplus.arrayOfObject(errors, 'errors');
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if (errors.length === 0) {
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return (null);
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}
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errors.forEach(function (e) {
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mod_assertplus.ok(mod_isError(e));
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});
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if (errors.length == 1) {
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return (errors[0]);
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}
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return (new MultiError(errors));
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};
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VError.errorForEach = function (err, func)
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{
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mod_assertplus.ok(mod_isError(err), 'err must be an Error');
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mod_assertplus.func(func, 'func');
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if (err instanceof MultiError) {
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err.errors().forEach(function iterError(e) { func(e); });
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} else {
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func(err);
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}
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};
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/*
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* SError is like VError, but stricter about types. You cannot pass "null" or
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* "undefined" as string arguments to the formatter.
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*/
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function SError()
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{
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var args, obj, parsed, options;
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args = Array.prototype.slice.call(arguments, 0);
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if (!(this instanceof SError)) {
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obj = Object.create(SError.prototype);
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SError.apply(obj, arguments);
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return (obj);
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}
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parsed = parseConstructorArguments({
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'argv': args,
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'strict': true
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});
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options = parsed.options;
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VError.call(this, options, '%s', parsed.shortmessage);
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return (this);
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}
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/*
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* We don't bother setting SError.prototype.name because once constructed,
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* SErrors are just like VErrors.
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*/
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mod_util.inherits(SError, VError);
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/*
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* Represents a collection of errors for the purpose of consumers that generally
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* only deal with one error. Callers can extract the individual errors
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* contained in this object, but may also just treat it as a normal single
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* error, in which case a summary message will be printed.
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*/
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function MultiError(errors)
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{
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mod_assertplus.array(errors, 'list of errors');
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mod_assertplus.ok(errors.length > 0, 'must be at least one error');
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this.ase_errors = errors;
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VError.call(this, {
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'cause': errors[0]
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}, 'first of %d error%s', errors.length, errors.length == 1 ? '' : 's');
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}
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mod_util.inherits(MultiError, VError);
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MultiError.prototype.name = 'MultiError';
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MultiError.prototype.errors = function me_errors()
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{
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return (this.ase_errors.slice(0));
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};
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/*
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* See README.md for reference details.
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*/
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function WError()
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{
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var args, obj, parsed, options;
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args = Array.prototype.slice.call(arguments, 0);
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if (!(this instanceof WError)) {
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obj = Object.create(WError.prototype);
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WError.apply(obj, args);
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return (obj);
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}
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parsed = parseConstructorArguments({
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'argv': args,
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'strict': false
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});
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options = parsed.options;
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options['skipCauseMessage'] = true;
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VError.call(this, options, '%s', parsed.shortmessage);
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return (this);
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}
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mod_util.inherits(WError, VError);
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WError.prototype.name = 'WError';
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WError.prototype.toString = function we_toString()
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{
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var str = (this.hasOwnProperty('name') && this.name ||
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this.constructor.name || this.constructor.prototype.name);
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if (this.message)
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str += ': ' + this.message;
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if (this.jse_cause && this.jse_cause.message)
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str += '; caused by ' + this.jse_cause.toString();
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return (str);
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};
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/*
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* For purely historical reasons, WError's cause() function allows you to set
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* the cause.
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*/
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WError.prototype.cause = function we_cause(c)
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{
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if (mod_isError(c))
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this.jse_cause = c;
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return (this.jse_cause);
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};
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