dotnet-getdocument support OpenAPI YAML format generation

[ArturAmpilogov]

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

dotnet-getdocument is the tool that is used by Microsoft.Extensions.ApiDescription.Server with Microsoft.AspNetCore.OpenApi to generate documentation at build time.

Currently, the tool can generate only JSON OpenAPI spec.
It would be nice to see YAML output as well, which has been commonly used with the Swagger generator.

Describe the solution you'd like

Support a flag to specify output format, for example

<OpenApiGenerateDocumentsOptions>--format yaml</OpenApiGenerateDocumentsOptions>

or similar to dotnet swagger

<OpenApiGenerateDocumentsOptions>--yaml</OpenApiGenerateDocumentsOptions>

Additional context

No response

[captainsafia]

@ArturAmpilogov Thanks for filing this issue! We're tracking improvements to the build-time generation space via #58353. Specifically, the proposal is to build on top of a new IApiPublisher API to support generation (see #61031).

I can see us achieving this in one of two ways in the new model coming in .NET 10:

• Registering two publishers openapi-yaml and openapi-json for each format
• Adding the document format to OpenApiOptions although this might not play well with the YAML endpoint that we previously created