[Analyzer] Detect adding middleware services but middleware isn't used

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.

Developers can add the services for middleware, e.g. AddCors, and not realize that the middleware needs to be registered in middleware with UseCors. There is no error or indication to the developer about what they’re missing.

Describe the solution you’d like

An analyzer that looks at what middleware services are registered, what middleware is used in request pipeline, and warns the developer about middleware that’s unused.

We can’t infer what these names are so we’d hard code AddMiddleware and UseMiddleware method names.

Additional context

No response

[davidfowl]

Yes this is the only analyzer suggestion I think shouldn’t be a warning by default. People will refactor things into methods and the analyzer will get confused quickly.

[msftbot[bot]]

Thanks for contacting us.

We’re moving this issue to the .NET 8 Planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s). If we later determine, that the issue has no community involvement, or it’s very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues. To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.