Add --experimental_allow_proto3_optional support

[LiuDongxu-Vungle]

protoc v3.12.0 is going to add experimental support for the optional annotation to proto3 (see RC: https://github.com/protocolbuffers/protobuf/releases/tag/v3.12.0-rc1). We may need to update our generator(s) (protoc-gen-grpc-gateway, protoc-gen-swagger). Doc for adding this ability is here: https://github.com/protocolbuffers/protobuf/blob/v3.12.0-rc1/docs/implementing_proto3_presence.md.

[srikrsna]

lyft/protoc-gen-star#75

[xmlking]

I am stuck with missing proto3 optional support for gotag and protoc-gen-validate plugins :)
I think I should stop using cutting edge
bufbuild/protoc-gen-validate#431

[k1ng440]

@srikrsna why this is closed? plugin still can't set tags to optional fields

https://puu.sh/HTKb2/80dd1311fb.png

[vtolstov]

Can you try to use protoc-gen-go-micro it supports setting tags

[srikrsna]

@k1ng440 Thank you for flagging it is now fixed in the latest release.

[colecrouter]

On the latest version 0.6.2 I'm still getting this error when using the optional keyword.

[srikrsna]

@Mexican-Man The example in the project uses optional can you share more info on when it's not working. A small reproducible repo perhaps?

[xmlking]

I actually tied with latest version. It works now

  optional string email = 10 [(tagger.tags) = "avro:\"email\" graphql:\"withNewTags,optional\"" ];

https://github.com/xmlking/grpc-starter-kit/blob/develop/proto/mkit/mkit/service/account/entities/v1/entities.proto#L25

Using with Buf tooling

[colecrouter]

@Mexican-Man The example in the project uses optional can you share more info on when it's not working. A small reproducible repo perhaps?

You're right, it works fine. I tried the older releases, but none of them do what I'm experiencing... I'm going to look into my deps for anything outdated/weird (old version of protoc?).

In the mean time: whoops! I'll close my pr, and I'll post back if I find anything.