Bleeding edge - GenericAncestorsCheck - do not allow trait

src/Rules/Generics/GenericAncestorsCheck.php

@@ -112,12 +112,28 @@ public function check(
 			}
 
 			foreach ($ancestorType->getReferencedClasses() as $referencedClass) {
-				if ($this->reflectionProvider->hasClass($referencedClass)) {
+				if (!$this->reflectionProvider->hasClass($referencedClass)) {
+					$messages[] = RuleErrorBuilder::message(sprintf($invalidTypeMessage, $referencedClass))
+						->identifier('class.notFound')
+						->build();
+					continue;
+				}
+
+				if (!$this->absentTypeChecks) {
+					continue;
+				}
+
+				if ($referencedClass === $ancestorType->getClassName()) {
+					continue;
+				}
+
+				$classReflection = $this->reflectionProvider->getClass($referencedClass);
+				if (!$classReflection->isTrait()) {
 					continue;
 				}
 
 				$messages[] = RuleErrorBuilder::message(sprintf($invalidTypeMessage, $referencedClass))
-					->identifier('class.notFound')
+					->identifier('generics.trait')
 					->build();
 			}
 

tests/PHPStan/Rules/Generics/ClassAncestorsRuleTest.php

@@ -127,6 +127,10 @@ public function testRuleExtends(): void
 				'Call-site variance annotation of covariant Throwable in generic type ClassAncestorsExtends\FooGeneric<covariant Throwable, InvalidArgumentException> in PHPDoc tag @extends is not allowed.',
 				246,
 			],
+			[
+				'PHPDoc tag @extends has invalid type ClassAncestorsExtends\FooTrait.',
+				259,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Generics/data/class-ancestors-extends.php

@@ -247,3 +247,16 @@ class FooTypeProjection extends FooGeneric
 {
 
 }
+
+trait FooTrait
+{
+
+}
+
+/**
+ * @extends FooGeneric<FooTrait, \InvalidArgumentException>
+ */
+class TraitInExtends extends FooGeneric
+{
+
+}