Detect calling static method on a trait

Author: ondrejmirtes

src/Rules/Methods/CallStaticMethodsRule.php

@@ -138,6 +138,15 @@ public function processNode(Node $node, Scope $scope): array
 				}
 
 				$classReflection = $this->reflectionProvider->getClass($className);
+				if ($classReflection->isTrait()) {
+					return [
+						RuleErrorBuilder::message(sprintf(
+							'Call to static method %s() on trait %s.',
+							$methodName,
+							$className
+						))->build(),
+					];
+				}
 			}
 
 			$className = $classReflection->getName();

tests/PHPStan/Rules/Methods/CallStaticMethodsRuleTest.php

@@ -216,6 +216,10 @@ public function testCallStaticMethods(): void
 				'Call to an undefined static method CallStaticMethods\Foo::nonexistentMethod().',
 				303,
 			],
+			[
+				'Call to static method doFoo() on trait CallStaticMethods\TraitWithStaticMethod.',
+				323,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Methods/data/call-static-methods.php

@@ -304,3 +304,23 @@ public function doFoo(
 	}
 
 }
+
+trait TraitWithStaticMethod
+{
+
+	public static function doFoo(): void
+	{
+
+	}
+
+}
+
+class MethodCallingTraitWithStaticMethod
+{
+
+	public function doFoo(): void
+	{
+		TraitWithStaticMethod::doFoo();
+	}
+
+}