How to send bytes data from client side?

[yuta-hidaka]

Hi!

I'm trying to send an array byte as a client stream.
When I tried to send the data, the grpc got EOF and never got data from the client side.
In the client side, I'm using Uint8Array as a byte array.(grapc-gateway converts bytes to Uint8Array in javascript)
I'm new to WebSocket, was I missing something?

If you need more detail I will create a minimal reproduction code.

.proto message definition is

message HealthCheckRequest {
    string health = 1;
    bytes buf = 2;
}

client-side is like this.

const byteMessage = new TextEncoder().encode("test message"); // create bytes(Uint8Array) for request
ws.send(JSON.stringify({ health: 'abc', buf: byteMessage})); // this code not working(got EOF)
ws.send(JSON.stringify({ health: 'abc'}));  // without `buf` property work correctly. And I could get data on the server side.

and the server side is like this.

func (s *Server) HealthCheckBiDiStream(stream pb.TranslatorService_HealthCheckBiDiStreamServer) error {
	cnt := 0
	for {
		_, err := stream.Recv()
		if err != nil && err != io.EOF {
			log.Fatal(err)
			return err
		}
		if err == io.EOF {
			return nil
		}

		stream.Send(&pb.HealthCheckResponse{
			Health: fmt.Sprintf("OK %d", cnt),
		})

		if err != nil {
			log.Fatal(err)
			return err
		}
		cnt += 1

	}

}