viki/node_modules/when/lib/format.js

/** @license MIT License (c) copyright 2010-2014 original author or authors */
/** @author Brian Cavalier */
/** @author John Hann */

(function(define) { 'use strict';
define(function() {

	return {
		formatError: formatError,
		formatObject: formatObject,
		tryStringify: tryStringify
	};

	/**
	 * Format an error into a string.  If e is an Error and has a stack property,
	 * it's returned.  Otherwise, e is formatted using formatObject, with a
	 * warning added about e not being a proper Error.
	 * @param {*} e
	 * @returns {String} formatted string, suitable for output to developers
	 */
	function formatError(e) {
		var s = typeof e === 'object' && e !== null && (e.stack || e.message) ? e.stack || e.message : formatObject(e);
		return e instanceof Error ? s : s + ' (WARNING: non-Error used)';
	}

	/**
	 * Format an object, detecting "plain" objects and running them through
	 * JSON.stringify if possible.
	 * @param {Object} o
	 * @returns {string}
	 */
	function formatObject(o) {
		var s = String(o);
		if(s === '[object Object]' && typeof JSON !== 'undefined') {
			s = tryStringify(o, s);
		}
		return s;
	}

	/**
	 * Try to return the result of JSON.stringify(x).  If that fails, return
	 * defaultValue
	 * @param {*} x
	 * @param {*} defaultValue
	 * @returns {String|*} JSON.stringify(x) or defaultValue
	 */
	function tryStringify(x, defaultValue) {
		try {
			return JSON.stringify(x);
		} catch(e) {
			return defaultValue;
		}
	}

});
}(typeof define === 'function' && define.amd ? define : function(factory) { module.exports = factory(); }));