jsonpb doesn't decode proto3 string enums

[maxhawkins]

Using the jsonpb package, I can marshal a proto3 message to JSON with enums as strings.

However, I cannot go in the reverse direction. The Unmarshal function returns an error when I try to unmarshal JSON with string enums.

I expected this to work how it does with proto2 messages.

Failing round-trip example here:

package main

import (
    "github.com/golang/protobuf/jsonpb"
    pb "github.com/golang/protobuf/proto/proto3_proto"
)

func main() {
    msg := &pb.Message{Hilarity: pb.Message_SLAPSTICK}

    marshaller := jsonpb.Marshaller{EnumsAsString: true}
    data, _ := marshaller.MarshalToString(msg)

    if err := jsonpb.UnmarshalString(data, msg); err != nil {
        panic(err)
    }
}

This code panics with json: cannot unmarshal string into Go value of type proto3_proto.Message_Humour.

[dsymonds]

In the (unpublished) spec, only the symbolic names are supported, but we should definitely permit round-tripping what we can produce.

[marcinwyszynski]

I believe this is still happening for repeated enum fields.

[dsymonds]

Can you please file a new issue for that, preferably with a reproduction case?

[marcinwyszynski]

Will do. I think I can spend some time on a fix, too.

[dinowernli]

FYI, I've opened #163 to fix the repeated enum thing.