#2845: Inherited [Collection] attribute not considered for xUnit1041

src/xunit.analyzers.tests/Analyzers/X1000/EnsureFixturesHaveASourceTests.cs

@@ -160,6 +160,32 @@ [Fact] public void TestMethod() {{ }}
 			await Verify.VerifyAnalyzer(source);
 		}
 
+		[Fact]
+		public async void WithInheritedFixture_DoesNotTrigger()
+		{
+			var source = @"
+using Xunit;
+
+public class Fixture { }
+
+[CollectionDefinition(""test"")]
+public class TestCollection : ICollectionFixture<Fixture> { }
+
+[Collection(""test"")]
+public abstract class TestContext {
+    protected TestContext(Fixture fixture) { }
+}
+
+public class TestClass : TestContext {
+    public TestClass(Fixture fixture) : base(fixture) { }
+
+    [Fact]
+    public void TestMethod() { }
+}";
+
+			await Verify.VerifyAnalyzer(source);
+		}
+
 		[Theory]
 		[InlineData("[Collection(nameof(TestCollection))]", "")]
 		[InlineData("", "[Collection(nameof(TestCollection))]")]

src/xunit.analyzers/X1000/EnsureFixturesHaveASource.cs

@@ -37,11 +37,14 @@ public override void AnalyzeCompilation(
 
 			// Get the collection name from [Collection], if present
 			var collectionAttributeType = xunitContext.Core.CollectionAttributeType;
-			var collectionDefinitionName =
-				namedType
-					.GetAttributes()
-					.FirstOrDefault(a => a.AttributeClass.IsAssignableFrom(collectionAttributeType))
-					?.ConstructorArguments.FirstOrDefault().Value?.ToString();
+			string? collectionDefinitionName = null;
+
+			for (var type = namedType; type is not null && collectionDefinitionName is null; type = type.BaseType)
+				collectionDefinitionName =
+					type
+						.GetAttributes()
+						.FirstOrDefault(a => a.AttributeClass.IsAssignableFrom(collectionAttributeType))
+						?.ConstructorArguments.FirstOrDefault().Value?.ToString();
 
 			// Need to construct a full set of types we know can be resolved. Start with things
 			// like ITestOutputHelper and ITestContextAccessor (since they're injected by the framework)