Support client streaming in grpc-web

[doctorpangloss]

I don't know why it's being emitted regardless of how I configure ts-proto.

Source example:

service A {
  rpc B(stream google.proto.Empty) returns (stream google.proto.Empty) {}
}

will generate

B(
      request: DeepPartial<Observable<Empty>>,
      metadata?: grpc.Metadata,
    ): Observable<HostReply> {
      return this.rpc.invoke(
        RemoteBDesc,
        Observable<Empty>.fromPartial(request),
        metadata,
      );
    }

version: 1.81.3
options:

        option "outputClientImpl=grpc-web"
        option "esModuleInterop=true"
        option "returnObservable=false"
        option "addGrpcMetadata=true"
        option "forceLong=number"
        option "oneof=unions"
        option "outputJsonMethods=false"
        option "lowerCaseServiceMethods=true"

[stephenh]

Yeah, hm, it looks like this line:

https://github.com/stephenh/ts-proto/blob/main/src/generate-grpc-web.ts#L65

Was written before/without realizing that this line:

https://github.com/stephenh/ts-proto/blob/main/src/types.ts#L540

Might return Observable, because streaming support was added later, and for a specific use case instead across the board for all combinations of options (as you're finding).

If you could reproduce in one of the integration/... directories that covers the grpc-web output, and submit a PR/fix, that'd be great. Thanks!

[stephenh]

Updating my prior diagnosis, this doesn't come from "we shouldn't use Observable here, it's that methods that are clientStreaming basically have to use Observable (to present the client is sending 0 or N messages, and so we need Observable to tell us when the last N-th message has been written by the client) and ts-proto doesn't have Observable / grpc-web wiring built yet.

[snyh]

The PR #617 is seems trying to support client stream for grpc-web

[stephenh]

This is fixed in #617 , thanks @luhuaei !

[luhuaei]

Try to support (client/server) streaming not Observable type. #633