protobuf well known types aren't represented in swagger output correctly

[tmc]

Durations appear in swagger as {"seconds": 0, "nanos": 0} though jsonpb marshals and unmarshals them in a string form like: "45.000s"

[tmc]

@yugui do you have thoughts here on how we should handle this problem? I'm happy to hack on a patch but have only been lightly watching the swagger and marshaler work.

[yugui]

I don't have much idea.

But the number of the well-known types is limited. So we could extend the mapping table to the swagger types.

[achew22]

@tmc with #209 in that provides a template for handling the custom times.

The special types are as follows:

• Timestamp
  • Already in Swagger and OpenAPI
• Duration (In neither Swagger nor OpenAPI
  • version/3.0: Add a 'duration' format OAI/OpenAPI-Specification#359
• Any
  • Should be serialized as {"@type": "url", "f": v, … } which I would guess is possible with the existing swagger spec
• Wrapper types
  • I'm not sure I totally understand the purpose of this. Is it just to provide nullability?
• Struct
  • Should be possible to implement as well

Do you need any of the other ones?

[stefanoj3]

Bump, and confirm that the issue is still there

[ianrose14]

jsonpb marshals and unmarshals them in a string form like: "45.000s"

Why is this? The Timestamp type by default will serialize as {"seconds": 0, "nanos": 0} so if you use any json-serializer on the client other than jsonpb you'll end up with a request body that jsonpb doesn't like on the server side. Why doesn't jsonpb just do the "normal" behavior and encode it the same way as encoding/json would do?

[achew22]

There is a set of well known types that are special coded in the proto3 spec when they are converted to JSON. This is the spec for duration

https://github.com/golang/protobuf/blob/master/jsonpb/jsonpb.go#L167
https://developers.google.com/protocol-buffers/docs/reference/google.protobuf#google.protobuf.Duration

[johanbrandhorst]

I believe this has been fixed in recent months.