Symlinked dependecy in `node_modules` cannot be resolved

[wjthieme]

I have a monorepo that contains various packages (built and tied together using nx). ts-mocha cannot resolve a package's dependencies on another local package.

For example:

- @org/a
  - foo.ts
- @org/b
  - node_modules (contains symlink for @org/a)
  - bar.ts (which imports from @org/a)
  - bar.test.ts (tests some function in bar.ts)

The error that ts-mocha throws is ERR_UNKNOWN_FILE_EXTENSION. If you remove the import from @org/a in bar.ts the same tests runs without issues.

[piotrwitek]

You haven't clarified, but are you using paths mappings?
Have you checked --paths setup? It is in the docs. Let me know if that's the case as the error seems similar.

Another thing you should check if the regular mocha is working, this way you can isolate source of the issue.