Strip import statement if all imports are removed.

[rwjblue]

Currently, given:

import { SOME_FLAG } from 'blah/features';

if (SOME_FLAG) {
  console.log('whatever');
}

With this config:

{
  plugins: [
    ['babel-debug-macros', {
      features: {
        name: 'blah',
        source: 'blah/features',
        flags: { SOME_FLAG: true }
      },
    }]
  ]
}

We remove the usage of SOME_FLAG, but leave the import statement. This forces us to also emit a blah/features module even if we never have runtime enableable features.

IMO, we should remove imports if they are no longer used...

[krisselden]

The module is still needed to run tests on prod.

[rwjblue]

@krisselden - Only if there are runtime features. If all features are stripped (e.g. they were all true or false, and none are null) the module is not needed at all.