Print useful stack-traces for combined/minified/compiled javascript files
Switch branches/tags
Nothing to show
Latest commit 90841c2 Aug 1, 2012 @janekp Update readme
Failed to load latest commit information.
lib Add javascript files Jul 31, 2012
.gitignore Add gitignore file Jul 31, 2012
LICENSE Add LICENSE Jul 31, 2012 Update readme Aug 1, 2012
index.js Add javascript files Jul 31, 2012
package.json Add package manifest Jul 31, 2012


A really simple library for printing human-readable stack-traces for combined, minified and/or compiled javascript files.

It assumes that your javascript file(s) have source maps (index.js -> etc).

For example the following stack-trace:

TypeError: Cannot read property 'length' of null
    at $extend.index (/Users/janekp/Documents/wixe/trunk/server/api/web/index.js:103:7)
    at Application.main.wixe1.route.ctx.template (/Users/janekp/Documents/wixe/trunk/server/api/web/index.js:12:24)
    at Object.wixe.Server.handle (/Users/janekp/Documents/wixe/trunk/server/api/web/index.js:253:5)
    at Object.handle (/Users/janekp/Documents/wixe/trunk/server/api/web/index.js:197:8)
    at next (/Users/janekp/Documents/wixe/trunk/server/api/web/node_modules/connect/lib/proto.js:190:15)
    at (/Users/janekp/Documents/wixe/trunk/server/api/web/node_modules/connect/lib/proto.js:198:3)
    at (/Users/janekp/Documents/wixe/trunk/server/api/web/node_modules/connect/lib/connect.js:66:31)
    at Server.EventEmitter.emit (events.js:91:17)
    at HTTPParser.parser.onIncoming (http.js:1785:12)
    at HTTPParser.parserOnHeadersComplete [as onHeadersComplete] (http.js:111:23)

becomes developer-friendly:

TypeError: Cannot read property 'length' of null:
    at 'if(x.length == 0) {' (.../trunk/server/api/src/RecipesPage.hx:45:25)
    at 'wixe.get('/:action/:id{0-9}', RecipesPage)' (.../trunk/server/api/src/Application.hx:15:7)
    at 'handler(ctx)' (.../server/api/src/wixe/Server.hx:290:23)
    at 'this.handle(req, res, next)' (.../server/api/src/wixe/Server.hx:306:37)
    ... (omitted 6 rows)

Installation and Dependencies

Install node.js for your platform

npm install mapstrace

It can be used with or without Connect

var mapstrace = require('mapstrace');

// Connect
var connect = require('connect');

// Stand-alone, true, function(result) {
    console.log(err.toString() + ':\n' + mapstrace.stringify(result));

The library can also be used to manually build a list of items and convert them into a string.

// err  - javascript Error object
// full - if true, then it will parse source files to fill missing fields.
// fn   - asynchronous callback that returns a list of items.
//        The list can contain objects and integers. Integers are used for unknown external items.
//        Every item has lineNumber, columnNumber, source and name fields. : Error, full : Bool, fn : Array -> Void) : Void;

// items  - A list of stack items (either numbers or objects).
// prefix - If not null then prefix is removed from paths. Optional, default is null
// limit  - The max number of path components. Optional, default is 5
// Returns a string.
mapstrace.stringify(items : Array, prefix : String, limit : Int) : String;