Allow noEmit and composite together in 3.7

[Volox]

TypeScript Version: 3.7.0-beta

Search Terms: composite noEmit monorepo

Expected behavior:

In 3.6 I was able to compile with those 2 options enabled now in 3.7 beta I cannot do that anymore.

Actual behavior:

error TS5053: Option 'noEmit' cannot be specified with option 'composite'.

Related Issues: No?

[RyanCavanaugh]

Sheetal Nandi (@sheetalkamat) this breaks vstsc for projects with composite because the task adds noEmit to the commandline

[amcasey]

As part of it's incremental compilation, VS runs a pass with --listEmittedFiles --listFiles --noEmit. cc Ben Lichtman (@uniqueiniquity)

[sheetalkamat]

interesting.. Technically with --noEmit shouldn't listEmittedFiles be empty list?

[amcasey]

Sheetal Nandi (@sheetalkamat), I would think so too, but Ben Lichtman (@uniqueiniquity) or Pranav Senthilnathan (@PranavSenthilnathan) would know more about why it's there.

[uniqueiniquity]

It should - I don't think --listEmittedFiles necessarily needs to be part of that pass.

[yacinehmito]

The issue seems to be back in 3.8.2.

[weswigham]

The revert was reverted again in #36483 because, per #32882, it really doesn't make sense to have incremental and noEmit together, since noEmit prevents us from writing incremental metadata. (So nothing is actually incremental).

You should consider emitDeclarationOnly instead of noEmit, if you actually just want incremental checking.

[yacinehmito]

Thank you. It makes sense.

[yacinehmito]

For other readers: the parameter to use is emitDeclarationOnly (declaration is singular).