file-loader using an 'exclude' pattern is too aggressive

[n0nick]

The change in package/rule/file.js as part of #1058 made file-loader catch all files not matching some exclude pattern instead of testing against a test pattern.

This means that any file extension not included in the hard-coded exclude pattern is treated by Webpack as a file and tries to generate a dynamic export.

In particular, I was using pug-loader with the following loader config:

{
  test: /\.(pug|jade)?$/,
  use: [
    {
      loader: 'pug-loader'
    }
  ]
};

But since the .jade and .pug file extensions are not part of the hard-coded exclude pattern, Webpack would generate a dynamic export which my app (import template from "file.jade" made template a path string instead of a template function).

[gauravtiwari]

Duplicate #1127