play nicely with coffeescript source maps

[zacronos]

CoffeeScript supports source maps - and correct line number mapping with errors.

http://jashkenas.github.com/coffee-script/documentation/docs/coffee-script.html

However, when longjohn is require'd, it messes with the line mapping -- probably something to do with the override of Error.prepareStackTrace. It would be great if longjohn could be fixed to show coffeescript source line numbers, when a coffeescript source map is available.

[zacronos]

This issue was originally identified in #11.

[drauggres]

$ npm install longjohn source-map-support coffee-script 
$ node_modules/coffee-script/bin/coffee --map --compile demo.coffee
$ cat demo.cofee

source_map = require('source-map-support')
source_map.install()
longjohn = require('longjohn');
longjohn.format_stack_frame = (frame) ->
  return longjohn.empty_frame if frame.getFileName() is longjohn.empty_frame
  return '    at ' + source_map.wrapCallSite(frame);
foo = ->
  bar = -> throw new Error 'this is a demo'
  bar()
setTimeout(
  lol = ->
    foo()
  , 1000)

$ node demo.js

/home/s.volkov/Proj/longjohn/dist/demo.coffee:8
  bar = -> throw new Error 'this is a demo'
                     ^
Error: this is a demo
    at bar (/home/s.volkov/Proj/longjohn/dist/demo.coffee:8:22)
    at foo (/home/s.volkov/Proj/longjohn/dist/demo.coffee:9:3)
    at [object Object].lol (/home/s.volkov/Proj/longjohn/dist/demo.coffee:12:5)
    at Timer.listOnTimeout [as ontimeout] (timers.js:121:15)
---------------------------------------------
    at Object.<anonymous> (/home/s.volkov/Proj/longjohn/dist/demo.coffee:10:1)
    at Object.<anonymous> (/home/s.volkov/Proj/longjohn/dist/demo.coffee:1:1)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:935:3

[mattinsler]

Thanks @drauggres!!!

I've changed the code and pushed it back up to support source maps through the method that @drauggres outlines above. You wouldn't need to install source-map-support, just compile your scripts with --map turned on and then run like normal.

Could someone pull the latest changes and try it out locally before I release a new version?

Thanks!

[mattinsler]

Published to npm as version 0.2.9.