make generated type import path ends in .js

[ignatiusmb]

Fixes #5899

Is there any other possible extensions? Should we have a utility function to extract and replace the extension of a filename?

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[juanvillacortac]

I confirm that this solves this problem which is really annoying. I hope it can be merged soon. This is making migrating to the new API quite annoying if I have my project strongly typed.

[dummdidumm]

Ah, interesting, I had the same problem in another case but didn't realize this would also affect TS proxies. I consolidated the logic 👍

[iceghost]

@igna Looks like this PR only add the extension to AwaitedErrors. AwaitedProperties fix is missing.