Consider inherited test methods when detecting test classes (CA1515 suppressor, xUnit1056)

[meziantou]

Problem

IsTestClassNonStrict only inspected type.GetMembers(), ignoring base types. A concrete class whose test methods are all inherited was not recognized as a test class:

using Xunit;

public abstract class BaseTests {
    [Fact]
    public void TestMethod() { }
}

public class DerivedTests : BaseTests { }

The CA1515 suppressor (MakeTypesInternalSuppressor) suppressed the warning on BaseTests but still reported it on DerivedTests — the class xUnit actually runs, which must be public.

Fix

IsTestClassNonStrict now uses GetInheritedAndOwnMembers(), so inherited [Fact]/[Theory] methods are taken into account. The abstract base class remains suppressed as well (it cannot be made internal while a public test class derives from it — CS0060).

Reviewer notes

The non-strict check is also used by xUnit1056 (TypeMustHaveSinglePublicConstructor). With this change, a class that inherits its tests and declares multiple public constructors is now flagged, which is correct since xUnit cannot construct it.

Tests

• CA1515 suppressor: added an abstract base test class and a derived class with inherited tests (both suppressed).
• xUnit1056: added a derived class with a default constructor (no diagnostic) and one with two public constructors (diagnostic).

Both new scenarios fail without the fix; the full test suite passes on net8.0.

[bradwilson]

Thanks!

[bradwilson]

Available in 2.2.0-pre.15 https://xunit.net/docs/using-ci-builds