# Source Map Support

This module provides source map support for stack traces in node via the [V8 stack trace API](http://code.google.com/p/v8/wiki/JavaScriptStackTraceApi). It uses the [source-map](https://github.com/mozilla/source-map) module to replace the paths and line numbers of source-mapped files with their original paths and line numbers. The output mimics node's stack trace format with the goal of making every compile-to-JS language more of a first-class citizen.

### Installation

    npm install source-map-support

This module takes effect globally and should be initialized by inserting a call to `require('source-map-support')` at the top of your code.

### CoffeeScript Demo

The following terminal commands show a stack trace in node with CoffeeScript filenames:

    $ cat > demo.coffee

    require 'source-map-support'
    foo = ->
      bar = -> throw new Error 'this is a demo'
      bar()
    foo()

    $ npm install source-map-support
    $ git clone https://github.com/michaelficarra/CoffeeScriptRedux.git
    $ cd CoffeeScriptRedux && npm install && cd ..
    $ CoffeeScriptRedux/bin/coffee --js -i demo.coffee > demo.js
    $ echo '//@ sourceMappingURL=demo.js.map' >> demo.js
    $ CoffeeScriptRedux/bin/coffee --source-map -i demo.coffee > demo.js.map
    $ node demo

    demo.coffee:4
      bar = -> throw new Error 'this is a demo'
                      ^
    Error: this is a demo
        at bar (demo.coffee:4:19)
        at foo (demo.coffee:5:3)
        at Object.<anonymous> (demo.coffee:6:3)
        at Object.<anonymous> (demo.coffee:6:6)
        at Module._compile (module.js:449:26)
        at Object.Module._extensions..js (module.js:467:10)
        at Module.load (module.js:356:32)
        at Function.Module._load (module.js:312:12)
        at Module.runMain (module.js:492:10)
        at process.startup.processNextTick.process._tickCallback (node.js:244:9)

Note that the steps above are just to demonstrate this library. If you want good stack traces for your own CoffeeScript project, you can run coffee files directly with CoffeeScriptRedux (use the `--eval` flag) and the stack traces will have the correct CoffeeScript line numbers.

### TypeScript Demo

The following terminal commands show a stack trace in node with TypeScript filenames:

    $ cat > demo.ts

    declare function require(name: string);
    require('source-map-support');
    class Foo {
      constructor() { this.bar(); }
      bar() { throw new Error('this is a demo'); }
    }
    new Foo();

    $ npm install source-map-support typescript
    $ node_modules/typescript/bin/tsc -sourcemap demo.ts
    $ node demo

    demo.ts:6
      bar() { throw new Error('this is a demo'); }
                   ^
    Error: this is a demo
        at Foo.bar (demo.ts:6:16)
        at new Foo (demo.ts:5:23)
        at Object.<anonymous> (demo.ts:8)
        at Module._compile (module.js:449:26)
        at Object.Module._extensions..js (module.js:467:10)
        at Module.load (module.js:356:32)
        at Function.Module._load (module.js:312:12)
        at Module.runMain (module.js:492:10)
        at process.startup.processNextTick.process._tickCallback (node.js:244:9)

### License

This code is available under the [MIT license](http://opensource.org/licenses/MIT).