Microsoft.AspNetCore.Grpc.Swagger doesn't respect WriteEnumsAsIntegers for request contracts

[James Abbott]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

When using the gRPC transcoding package to generate swagger definitions, the generated swagger is incorrect when using enums.

I've spent some time narrowing this down and have reproduced the behaviour - it appears to be when using an enum in a .proto file- if that enum is only used in a response contract, then the generated swagger states the response type to be a string type enum. Whenever, however, an enum is used in a request contract, then the swagger type is created as an integer:

Generated from the following .proto file:
greet.proto.txt

Expected Behavior

When using an enum in a request message for a gRPC transcoded API, the generated swagger definition should show that enum as a string when WriteEnumsAsIntegers is false.

Steps To Reproduce

I've created a repo here that demonstrates the issue: https://github.com/abbottdev/grpc-swagger-repo

This change may be related to #51036

If you clone the repo, dotnet run and browse to the swagger site: http://localhost:5122/swagger/ you'll see the ResponseOnlyEnum generated type is a string, but the RequestOnlyEnum and SharedEnum are both created as int32

Exceptions (if any)

No response

.NET Version

8.0

Anything else?

Asp.NET Core 8.0.5 and associated packages