Generic attributes lack testing

[MichalStrehovsky]

We need reflection tests that test generic attributes.

dotnet/linker#2963 made it clear that we don't have any targeted reflection tests for the new scenario in the libraries partition. The newly added test is not a targeted reflection test - it's a S.R.Metadata test.

Tagging subscribers to this area: @dotnet/area-system-reflection
See info in area-owners.md if you want to be subscribed.

Issue Details

---

We need reflection tests that test generic attributes.

dotnet/linker#2963 made it clear that we don't have any targeted reflection tests for the new scenario in the libraries partition. The newly added test is not a targeted reflection test - it's a S.R.Metadata test.

Author:	MichalStrehovsky
Assignees:	-
Labels:	area-System.Reflection, up-for-grabs
Milestone:	-

[buyaa-n]

We have some tests, but might need to improve the coverage

[MichalStrehovsky]

The specific tests that are needed are tests that are using the generic type's T in the signatures (that's the bug we ran into).

So things like:

class FooAttribute<T>: Attribute { public FooAttribute(T value, T[] othervalue) { } }
class BarAttribute<T> : Attribute { public T SomeValue { get; set; } }

The existing tests are not testing much because they don't use the T.

[MichalStrehovsky]

I would definitely at least put it in 8.0 but AFAIK generic attributes are new in C# for .NET 7.0 so we should have testing in place to make sure reflection on them actually works in various scenarios.

Cc @333fred

[buyaa-n]

I would definitely at least put it in 8.0 but AFAIK generic attributes are new in C# for .NET 7.0 so we should have testing in place to make sure reflection on them actually works in various scenarios.

Sure, we will reevaluate all issue during 8.0 planning

[333fred]

AFAIK generic attributes are new in C# for .NET 7.0

That's correct.

[steveharter]

Moving to 9; the mono bug linked above unfortunately didn't add a test that would have helped here.