index.js

/**
 * simple-errors module
 *
 * Create errors with simple factory methods for easy error handling.
 * License: BSD
 */

/**
 * Use Error.create(msg [, data [, inner]]) to create Error instances.
 * function create
 * @param msg (string)
 * @param data (any type) adds metadata to the Error instance
 * @param inner (any type) for chaining errors
 * @api public
 */
Error.create = function ( msg, data, inner ) {
	
	data = data || {};

	var err = new Error(msg || "Unknown error");

	var innerValue = inner || (data instanceof Error ? data : null);
	if (innerValue) err.inner = innerValue;

	if (data instanceof Array || typeof(data) !== 'object') {

		err.data = data;

	} else {

		Object.keys(data).forEach(function (key) {
			err[key] = data[key];
		});
	}

	return err;
};

/**
 * Use Error.http([code] [, msg [, data [, inner]]]) to create Error instances with status codes.
 * @param code (numeric) adds status property to the error.
 * @param msg (string)
 * @param data (any type) adds metadata to the Error instance
 * @param inner (Error|string) for chaining errors
 */
Error.http = function (code, msg, data, inner) {
	
	if (typeof(code)==='string') {
		inner = data;
		data = msg;
		msg = code;
		code = 500;
	}

	code = code || 500;
	msg = msg || statusCodes["" + code] || 'Unknown error';
	
	var err = Error.create(msg, data, inner);
	err.status = code;
	return err;
};

/**
 * Turn an Error instance into a json object recursively. Use this function
 * for printing the entire error (even the stacks).
 * @param err (Error|Object)
 * @api public
 */
Error.toJson = function ( err ) {
	
	if (typeof(err)==='string') return { message: err};

	var info = {};
	if (err instanceof Error) {
		info.message = err.message;
		info.stack = err.stack.split("\n");
    }

    if (typeof(err) === 'object') {
		for (var prop in err) {
			var value = err[prop];
			info[prop] = (value instanceof Error) ? Error.toJson(value) : value;
		}
	}
    
    return info;
};


var statusCodes = {
	"400": "Bad Request",
	"401": "Unauthorized",
	"402": "Payment Required",
	"403": "Forbidden",
	"404": "Not Found",
	"405": "Method Not Allowed",
	"406": "Not Acceptable",
	"407": "Proxy Authentication Required",
	"408": "Request Timeout",
	"409": "Conflict",
	"410": "Gone",
	"411": "Length Required",
	"412": "Precondition Failed",
	"413": "Request Entity Too Large",
	"414": "Request-URI Too Long",
	"415": "Unsupported Media Type",
	"416": "Requested Range Not Satisfiable",
	"417": "Expectation Failed",
	"418": "I'm a teapot",
	"422": "Unprocessable Entity",
	"423": "Locked",
	"424": "Failed Dependency",
	"425": "Unordered Collection",
	"426": "Upgrade Required",
	"428": "Precondition Required",
	"429": "Too Many Requests",
	"431": "Request Header Fields Too Large",
	"500": "Internal Server Error",
	"501": "Not Implemented",
	"502": "Bad Gateway",
	"503": "Service Unavailable",
	"504": "Gateway Timeout",
	"505": "HTTP Version Not Supported",
	"506": "Variant Also Negotiates",
	"507": "Insufficient Storage",
	"508": "Loop Detected",
	"510": "Not Extended",
	"511": "Network Authentication Required"
};