Make `CreateFilteredDocument` filter out unused components

[erwinkramer]

Is your feature request related to a problem? Please describe.
Currently, the CreateFilteredDocument method doesn't filter out any component that is left over after filtering out operations.

Describe the solution you'd like
FilterDocumentOptions type or something similar that allows me to have a more advanced filtering behavior. Which should have a revamped copy implementation:

OpenAPI.NET/src/Microsoft.OpenApi/Services/OpenApiFilterService.cs

Line 238 in 43c75a9

private static void CopyReferences(OpenApiDocument target)

Additional context
Try to filter the Graph API spec from https://raw.githubusercontent.com/microsoftgraph/msgraph-metadata/refs/heads/master/openapi/v1.0/openapi.yaml with the current implementation to get a clear picture as to why it's an issue. It leaves so many components (particularly the schemas) it's just not practical to use at the moment.

[baywet]

Hi @erwinkramer
Thank you for using the SDK and for reaching out.

This should be fairly simple to implement:

1. Add an overload to the walker walk method allowing to pass a configuration to let the user decide which document nodes to walk (we can't use an optional parameter for binary compatibility reasons)
2. Implement a visitor that collects reference keys
3. Get all the keys of components that are not in that set of collected keys
4. Drop them from the components.
   All of that needs to happen after the copy references has happened for structural reasons.

Is this something you'd like to submit a pull request for provided some guidance?

[erwinkramer]

Thanks for your response @baywet.

Short term I have no interest in picking this up.

Regarding your implementation steps, they look good. However, did u consider that components also reference components, which in turn might or might not be referenced in an actual path inside the document? That makes it a little bit more complex but probably overcomeable.