Mozilla, WebKit To Support Debugging Minified JS As Well As CoffeeScript and other JS Languages
console.log() messages and other source related functionality.
The problem's not new; JVM languages had the problem too, which led to JSR-045 - Debugging Support for Other Languages, which is used for various languages compiling to the JVM, like JRuby.
Both the Mozilla and the WebKit projects have started work on supporting SMAPs in their debugging features.
Mozilla has an in-depth planning document for the SMAP and debugging functionality. The document also mentions yet another potential area for source mapping: CSS, which is also used as compilation target by supersets of CSS such as SASS or LESS.
The Mozilla ticket tracking the work is Bug 618650 - Map JS source coordinates to source language that was translated to JS; the planning document lists Firefox 9 as target release.
WebKit is also planning SMAP support, and the actual SMAP format might be an evolved version of the Closure Inspector format, which is considered by Mozilla as well. Bug 63940 - Web Inspector: draft implementation of compiler source mappings support in debugger tracks the development of the feature.
Jeffrey 'jf' Lim
Re: Firefox 9
Ian Culling, Andy Powell & Lee Cunningham Dec 11, 2013