Issue with paths in Source Map files

[thanpolas]

The sourceMap file is generated by the Google Closure Compiler (GCC). GCC does not -yet- provide a way to mangle with the paths in the sources key of the sourceMap file. As a result the mappings will not work.

Suppose your Javascript application is under the folder js/ and the build output and sourceMap file is in the folder dist/. The generated sourceMap sources key will look like this:

{
  "version":3,
  "file":"dist/app.min.js",
  "lineCount":561,
  "mappings":"KAFJ,CAAR;",
  "names":["a","b"],
  "sources":[
    "js/vendor/jquery.min.js",
    "js/vendor/handlebars.min.js",
    "js/app.js"
  ]
}

As the paths are relative and the sourceMap file was accessed from the /dist/app.min.map location, your browser will be directed to look into /dist/js/app.js instead of /js/app.js.

Right now, there are three solutions to this problem, the following one:

The symbolic-link of shame

The quick and dirty solution would be to create a symbolink link in your dist/ folder pointing to the js/ folder.

Waiting on the other solutions

The other two possible solutions is to either implement a post-processor that will manipulate the generated sourceMap file (PRs welcome!), or waiting for the ultimate solution of GCC implementing the sourceRoot option.