Fix calling gRPC stub if proto-scheme contains nested enum

[ashashev]

Problem

Calling of gRPC stub fails if the stub contains proto-scheme with nested enum. Regardless of whether message with the nested enum is used or not.

Steps to reproduce bugs

The following proto-file occurs the problem.

syntax = "proto3";

message Request {
    string text = 1;
}

message Response {
    enum Code {
      OK = 0;
      FAIL = 1;
    } 
    optional Code code = 1;
}                  

service Service { 
    rpc Call (Request) returns (Response);
}

Creating service:

curl -X POST -d '{"suffix":"first", "name":"first"}' http://localhost:8228/api/internal/mockingbird/v2/service

Creating a stub using the prototype above:

curl -i -X POST localhost:8228/api/internal/mockingbird/v2/grpcStub -d \
'{
  "name": "GRPC ***",
  "labels": [],
  "scope": "persistent",
  "methodName": "Service/Call",
  "requestCodecs": "c3ludGF4ID0gInByb3RvMyI7CgptZXNzYWdlIFJlcXVlc3QgewogICAgc3RyaW5nIHRleHQgPSAxOwp9CgptZXNzYWdlIFJlc3BvbnNlIHsKICAgIGVudW0gQ29kZSB7CiAgICAgIE9LID0gMDsKICAgICAgRkFJTCA9IDE7CiAgICB9CiAgICBvcHRpb25hbCBDb2RlIGNvZGUgPSAxOwp9CgpzZXJ2aWNlIFNlcnZpY2UgewogICAgcnBjIENhbGwgKFJlcXVlc3QpIHJldHVybnMgKFJlc3BvbnNlKTsKfQo=",
  "requestClass": "Request",
  "requestPredicates": {},
  "responseCodecs": "c3ludGF4ID0gInByb3RvMyI7CgptZXNzYWdlIFJlcXVlc3QgewogICAgc3RyaW5nIHRleHQgPSAxOwp9CgptZXNzYWdlIFJlc3BvbnNlIHsKICAgIGVudW0gQ29kZSB7CiAgICAgIE9LID0gMDsKICAgICAgRkFJTCA9IDE7CiAgICB9CiAgICBvcHRpb25hbCBDb2RlIGNvZGUgPSAxOwp9CgpzZXJ2aWNlIFNlcnZpY2UgewogICAgcnBjIENhbGwgKFJlcXVlc3QpIHJldHVybnMgKFJlc3BvbnNlKTsKfQo=",
  "responseClass": "Response",
  "response": {
    "mode": "fill",
    "data": {
      "code": "OK"
    }
  },
  "state": null,
  "seed": null,
  "service": "first"
}' \

Calling the stub:

grpcurl \
  -proto bad.proto \
  -d '{
  "text": "qwe123"
}' \
  -plaintext localhost:9000 \
  'Service/Call'

The expected result of this call, it is successful and returns { "code": "OK" }, but in reality it returns an error.

@mockingbird/maintainers