Testing ASP.NET Core with trimming

[JamesNK]

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.

We're annotating ASP.NET Core for trimming in .NET 7. In theory, the linker and trim warnings should ensure frameworks, libraries and apps work.

We should double-check that ASP.NET Core continues to run in some trimmed, published apps.

Describe the solution you'd like

With trimming it's difficult to test trimmed features in isolation, e.g. an app uses features A and B. Did A and B only work because they were both used, etc. Building and running an app to test each feature in isolation isn't realistic.

We should do some basic smoke testing of core scenarios.

e.g.
MVC
Minimal API
SignalR
AuthN/AuthZ
Kestrel/IIS/HttpSys
Data protection/security/identity

Additional context

No response

[javiercn]

@JamesNK you can take inspiration on how we test trimming in Blazor Webassembly apps. We trim the projects on the CI only based on the Release configuration.

[mkArtakMSFT]

@JamesNK how do you want all of us to track this? Do you want to put out a PR to which everyone will contribute or file separate issues?

Thanks for contacting us.

We're moving this issue to the .NET 7 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.

[hez2010]

Seems that Blazor doesn't support /p:TrimMode=full (with .NET 7 nightly sdk). If I use /p:TrimMode=full while publishing, even a hello world blazor wasm website will fail to load because of trimming.