Generated code contains error "is not a function call" for basic sample .proto

[Meai1]

This file creates a problem:

syntax = "proto2";
service PeerService {
    rpc Request (Message) returns (Message) {}
}
message Message {
}

Workaround:
If I rename the "Request" method to anything else, it generates error free code. I think it should work anyway though, seems weird that it breaks on a certain identifier.

[sigurdm]

Thanks for reporting this.
I have a fix coming up for this, I just need to write a regression test for it.

[osa1]

This looks like a grpc-dart issue. Should we close it? I learned recently that rpc syntax is handled by this library.

[osa1]

I talked to @sigurdm about this. The issue is in this generated code:

abstract class PeerServiceBase extends $grpc.Service {
  $async.Future<$0.Message> request_Pre(
      $grpc.ServiceCall call, $async.Future<$0.Message> request) async {
    return request(call, await request); // <-------- this line
  }

  $async.Future<$0.Message> request($grpc.ServiceCall call, $0.Message request);
}

In the marked line above, the first request is supposed to be the request method a few lines below, but the request argument shadows it, causing the error.

The argument name is hard-coded as request. The method at the bottom is generated based on RPC method name.

rpc Call ... also reproduces the issue as we also have an argument in ..._Pre method with name call.

To fix this we should avoid shadowing stuff with argument names in generated methods. We should somehow make sure we generate unique names for arguments. Depending on how we generate method names it may suffice to add $_ prefix, or some suffix etc. to the argument names.

[osa1]

@sigurdm points out that we could also add this. to the method call. I like this approach more as we don't have to think about unique argument name generation.

[osa1]

#485 is the same issue but the method name is New instead of Request.