[BUG] Module augmentation causes import to be tree-shaken (is removed from output)

[matthew-dean]

I'm not certain this is a ts-macros bug or a ts-patch bug, but my perception would be that:

1. ts-patch shouldn't be doing anything except allowing patching (unless that's incorrect)
2. ts-macros is the only transformer I'm using

The bug and all its details are here.

To re-summarize:

// chevrotain.d.ts
declare module 'chevrotain' {
  interface CstParser {
    // things that augment this type
  }
}


// cssParser.ts
import { CstParser, EOF } from 'chevrotain'

class CssParser extends CstParser {
 // class implementation
}

// outputs
import { EOF } from 'chevrotain'

Someone on the TypeScript team investigated and said that disabling ts-patch (which disables ts-macros) solves this bug.

[GoogleFeud]

Hello! Yes, the issue is definitely coming from this library, thanks for the bug report!

[matthew-dean]

Awesome, thanks so much!