A progress roughly corresponds to an api call. It is used:
- to collect logs related to the call;
- to handle timeout;
- to provide "cancellation token" behavior so that cancelable process can either
early-exit with progress.throwIfCanceled() or race against it with progress.race();
- to ensure resources are disposed in the case of a failure
with progress.cleanupWhenCanceled();
- (possibly) to log api calls if needed;
- (in the future) to augment async stacks.
Currently in our API `?` means null, but sometimes it means optional. Linting optional/nulls with this patch is required for #1166 to land nicely.
Previously, return types were not being linted in `api.md`. This is fixed, along with many broken return types.
This patch considers `?` to mean nullable, and has some heuristics to determine optionality. I believe this to be the minimal patch needed to unblock #1166. After it lands, we can consider changing the api docs to hopefully remove some heuristics and strangeness.
