successful calls still emit 'cancelled' as of v1.10.x

[davidfiala]

I was working on adding v1.10.x support to the https://github.com/deeplay-io/nice-grpc repos.

As lightly documented in deeplay-io/nice-grpc#555 (comment) I believe I discovered that server call handlers emit 'cancelled' even on successful RPCs. The v1.9.x series does not appear to do this. It appears to have been introduced behavior in the server-interceptor.ts file in 1.10.0 merge.

Is the behavior of always emitting call cancelled an explicit intention? Or a possible bug?

Thanks for your time.

[murgatroid99]

Yes, that was intentional.

From my point of view, the primary purpose of the cancelled signal is to notify the handler and any interceptors that no more processing is needed, and any resources associated with the call can be discarded, when they might otherwise not know that. Previously, that would only happen because of network events or calling Server#forceShutdown, but now it can also happen if a server interceptor ends a call on its own. As a result, the simplest way to ensure that the handler always gets that notification is to emit the cancelled event if the call ends in any way.

[davidfiala]

Thank you for the clarification.