gogofast generated proto files aren't compatible with "github.com/golang/protobuf/jsonpb"

[gyuho]

This code only works when WatchRequest is generated with gofast but doesn't work when it is generated with gogofast:

protoc --gofast_out=plugins=grpc:. \
    --proto_path=$GOPATH/src:$GOPATH/src/github.com/gogo/protobuf/protobuf:. \
    *.proto;

protoc --gogofast_out=plugins=grpc:. \
    --proto_path=$GOPATH/src:$GOPATH/src/github.com/gogo/protobuf/protobuf:. \
    *.proto;

syntax = "proto3";
package main;

import "github.com/gogo/protobuf/gogoproto/gogo.proto";

message WatchRequest {
  oneof request_union {
    WatchCreateRequest create_request = 1;
  }
}

message WatchCreateRequest {
  bytes key = 1;
}

import (
    "fmt"
    "log"

    "github.com/golang/protobuf/jsonpb"
)

func main() {
    const input = `{"create_request": {"key": "Zm9v"}}`
    var req WatchRequest
    if err := jsonpb.UnmarshalString(input, &req); err != nil {
        log.Fatal(err)
    }
    fmt.Printf("success with %+v\n", req.RequestUnion)
    // success with &{CreateRequest:key:"foo" } or unknown field "create_request" in main.WatchRequest
}

Here's the sample proto and generated files and script to reproduce this issue:

golang-vs-gogo-proto-issue.tar.gz

Reference

• watch over grpc-gateway etcd-io/etcd#5865
• Support oneof types of fields grpc-ecosystem/grpc-gateway#82 (comment)

[awalterschulze]

Does this fix your problem?
b5aec62

[gyuho]

Yes it does. Found some other issue (etcd-io/etcd#5969), but I don't think it's related to gogo/protobuf.

Thanks a lot, @awalterschulze!

[awalterschulze]

My pleasure :)

Just a note: I only used your issue report (which was great) and not the zip. I tried using the zip file to help me debug and fix the issue, but it was not really useful. So you can save yourself the effort next time. If you really want to make an effort a pull request with a failing test (in the test folder) will help me the most, but your report was perfect and already a big help.