[Analyzer] : Warn when registering custom IProblemDetailsWriter after calling AddRazorPages, etc

[Rick-Anderson]

Background and Motivation

Registering a custom IProblemDetailsWriter after calling AddRazorPages, etc results in the DefaultProblemDetailsWriter, not the custom IProblemDetailsWriter being called.

Proposed Analyzer

Analyzer Behavior and Message

Issue a warning when Registering a custom IProblemDetailsWriter after calling AddRazorPages, etc.

ASP0001: Authorization middleware is incorrectly configured is similar.

See dotnet/AspNetCore.Docs#29152

Note: When using a custom IProblemDetailsWriter, the custom IProblemDetailsWriter must be registered before calling AddRazorPages, AddControllers, or AddControllersWithViews.

Category

• Design
• Documentation
• Globalization
• Interoperability
• Maintainability
• Naming
• Performance
• Reliability
• Security
• Style
• Usage

Severity Level

• Error
• Warning
• Info
• Hidden

Usage Scenarios

Issue a warning when Registering a custom IProblemDetailsWriter after calling AddRazorPages, etc.

Risks

None.

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.
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[david-acker]

We could add this new analyzer to the Microsoft.AspNetCore.Analyzers project in src/Analyzers since a similar middleware analyzer (UseAuthorizationAnalyzer) for ASP0001 lives there. Then we can leverage the existing middleware information that's available on the StartupAnalysis context and then register the new analyzer alongside the others StartupAnalyzer.

[david-acker]

Here's a simple suggestion for the title and message of the new diagnostic:

Title: Custom IProblemDetailsWriter is incorrectly configured
Message: The custom IProblemDetailsWriter must be registered before calling AddControllers, AddControllersWithViews, AddMvc, or AddRazorPages.

[david-acker]

I'd be happy to put up a PR for this once the API for the new diagnostic is approved.

[david-acker]

We'll want to report this diagnostic for AddMvc as well, since it calls AddControllersWithViews and AddRazorPages internally.