Looks like you're introducing a change to the public API surface area. If this includes breaking changes, please document them on our wiki's API Breaking Changes page.

Also, please make sure @DanielRosenwasser and @RyanCavanaugh are aware of the changes, just as a heads up.

@microsoft-github-policy-service agree

I think my only question left is whether or not getPromisedTypeOfPromise is the one that should be exported; it was used in #59316 in favor of getAwaitedType. Not 100% certain this case is the same.

getPromisedTypeOfPromise does not account for generics, e.g., the "promised type" of Promise<T> is T, even though T could be instantiated with something like a Promise<number>. getAwaitedType accounts for generics, as it will also get the "promised type" but will wrap the result in Awaited<T> if the "promised type" is generic.

That said, if we expose getAwaitedType we might want to consider also exposing unwrapAwaitedType in the event you actually want the T.

Ah, gotcha. I think people are mainly wanting to simulate the result of the await operator, so in that sense this function seems correct (and I have some PRs to ts-eslint that would use it).

Updated the PR; I'm hoping to sneak this in to 5.6, given this function's been exported for a while now so this is really just a doc change... @DanielRosenwasser do you think it's too late for this sort of change?

For reference, this function was first added to TypeChecker in #36654, so has been available since TS 4.0.