proto3 support for optional

[SoerenBusse]

Proto3 supports the optional keyword. All libraries supporting this keyword needs to indicate this explicitly. Otherwise the complication will fail with is a proto3 file that contains optional fields, but code generator protoc-gen-python_betterproto hasn't been updated to support optional fields in proto3. Please ask the owner of this code generator to support proto3 optional.

Would it be possible to enable proto3 optional?

See this issue for more detail: vmagamedov/grpclib#125

[nat-n]

Thanks for bringing this up. Looks like this was quite recently added as a fully supported feature: https://github.com/protocolbuffers/protobuf/releases/tag/v3.15.0

This is kinda of a significant change to proto3 semantics, and will take a bit of thought about how to best adapt the API to support it. It doesn't look like the official proto3 guide has been updated to reflect this yet, but I found this guide which looks highly relevant: https://chromium.googlesource.com/external/github.com/protocolbuffers/protobuf/+/refs/heads/master/docs/implementing_proto3_presence.md

Updating the Message metadata model to support this should allow the removal of this hack in the plugin:

python-betterproto/src/betterproto/plugin/models.py

Line 119 in 95339bf

def monkey_patch_oneof_index():

[marianhlavac]

Is there any progess on this? It's currently very important feature for us, and we're forced to use official python protoc plugin for now.

[roblabla]

Hello, this is also very important for us. Is there any plan/timeline for this feature? What can we do to help speed up the implementation?

[kalzoo]

My comment on #35 would have made more sense here - the quick-fix might be to just treat optional fields as single-variant oneof to unblock parsing definitions which include it.

[jdlourenco]

Are there any news on this?

[Gobot1234]

Yes this is nearly ready but there is an issue with the fields recursing infinitely #281

[jdlourenco]

@Gobot1234 are tests only failing on the pipeline? I ran poe test and poetry run pytest tests/ locally and they ran successfully.

[Gobot1234]

I'm not entirely sure what's up with it, @kalzoo is the person you should be asking if you'd be willing to do some debugging and provide a fix for the failing tests it will get merged and then beta 4 can be shipped with support for this.

[Gobot1234]

v.2.0.0b4 has just been released and includes support for this.

[atulsriv]

This is gonna be a long shot, but I am still seeing this error. I am on version of v.2.0.0b6, I have libprotoc 3.21.9. It should be working for me, but I still run into this error. been stuck for a few days, so if anyone has any ideas please lmk thanks

[seansica]

Issue still occurring.

Error:

src/foo/bar/message.proto: is a proto3 file that contains optional fields, but code generator protoc-gen-python_betterproto hasn't been updated to support optional fields in proto3. Please ask the owner of this code generator to support proto3 optional.

pyproject.yaml:

protobuf = "^5.29.2"
betterproto = {extras = ["compiler"], version = "^1.2.5"}

❯ poetry run python -m pip list | grep proto
betterproto        1.2.5
mypy-protobuf      3.6.0
protobuf           5.29.2
types-protobuf     5.29.1.20241207
❯ poetry run python --version
Python 3.11.9

Relevant snippet of .proto file:

message Foo {
  // ..
  optional string foo = 45;
  // ...
  optional bool bar = 49;
}

[Gobot1234]

Use 2.0.0b6 please

[seansica]

Use 2.0.0b6 please

Thanks, that appears to work