falling demo

[mightyaleksey]

Hi, looks like I found a nasty bug :)

[mightyaleksey]

Also I think, that _compose_node_module_cool_styles_foo__example is not a valid generated class name, because it is a part of the external module.

Took me some time figure out why that problem appear. When fetch() resolves path to the external module, which lies beyond the root directory, you usually get something like that: ../../node_modules/....
Later, when you pass it to postcss, something normalizes it to /node_modules/..., which makes it impossible to do futher resolutions.

{ [Error: ENOENT, open '/home/travis/build/css-modules/css-modules-loader-core/test/test-cases/compose-node-module/cool-styles/bar.css']
  errno: -2,
  code: 'ENOENT',
  path: '/home/travis/build/css-modules/css-modules-loader-core/test/test-cases/compose-node-module/cool-styles/bar.css' }

[mightyaleksey]

I think that we should pass an absolute path to the source file as an extra argument to the parser plugin, so it can possible to put it back to the fetch() function:
https://github.com/css-modules/css-modules-loader-core/blob/master/src/index.js#L14
https://github.com/css-modules/css-modules-loader-core/blob/master/src/parser.js#L57

That will help us to resolve paths and build rootRelativePath. What you think about it?

[mightyaleksey]

We are handling error at the file-system-loader module, so no need to do it here.