Better union method call handling

Author: pepakriz

src/Rules/ThrowsPhpDocRule.php

@@ -23,13 +23,12 @@
 use PHPStan\Rules\Rule;
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\Type;
+use PHPStan\Type\TypeCombinator;
 use PHPStan\Type\TypeUtils;
 use ReflectionMethod;
 use function array_diff;
 use function array_filter;
 use function array_map;
-use function array_merge;
-use function array_unique;
 use function count;
 use function is_string;
 use function sprintf;
@@ -113,25 +112,31 @@ public function enableCallPropagation(): Rule
 			$targetType = $scope->getType($node->var);
 			$targetClassNames = TypeUtils::getDirectClassNames($targetType);
 
-			$messages = [];
+			$throwTypes = [];
 			foreach ($targetClassNames as $targetClassName) {
 				$targetClassReflection = $this->broker->getClass($targetClassName);
 				if (!$targetClassReflection->hasMethod($methodName->toString())) {
-					return [];
+					continue;
 				}
 
 				$targetMethodReflection = $targetClassReflection->getMethod($methodName->toString(), $scope);
-
 				if (!$targetMethodReflection instanceof ThrowableReflection) {
-					return [];
+					continue;
+				}
+
+				$throwType = $targetMethodReflection->getThrowType();
+				if ($throwType === null) {
+					continue;
 				}
 
-				$messages = array_merge($messages, $this->processThrowsTypes(
-					$targetMethodReflection->getThrowType()
-				));
+				$throwTypes[] = $throwType;
+			}
+
+			if (count($throwTypes) === 0) {
+				return [];
 			}
 
-			return array_unique($messages);
+			return $this->processThrowsTypes(TypeCombinator::union(...$throwTypes));
 		});
 	}
 

tests/src/Rules/data/throws-annotations.php

@@ -11,6 +11,7 @@ abstract class BaseRuntimeException extends RuntimeException {}
 abstract class BaseBlacklistedRuntimeException extends BaseRuntimeException {}
 class SomeRuntimeException extends BaseRuntimeException {}
 class NextRuntimeException extends BaseRuntimeException {}
+class ConcreteNextRuntimeException extends NextRuntimeException {}
 class SomeBlacklistedRuntimeException extends BaseRuntimeException {}
 class SomeInheritedBlacklistedRuntimeException extends BaseBlacklistedRuntimeException {}
 class CheckedException extends Exception {}
@@ -130,6 +131,16 @@ public function createNewInstance(): void
 		new ThrowInConstructor(); // error: Missing @throws RuntimeException annotation
 	}
 
+	/**
+	 * @throws NextRuntimeException
+	 */
+	public function callUnion(): void
+	{
+		/** @var UnionOne|UnionTwo|UnionThree $union */
+		$union = getUnion();
+		$union->foo(); // error: Missing @throws Pepakriz\PHPStanExceptionRules\Rules\Data\SomeRuntimeException annotation
+	}
+
 }
 
 class ThrowInConstructor
@@ -145,6 +156,40 @@ public function __construct()
 
 }
 
+class UnionOne  {
+
+	/**
+	 * @throws SomeRuntimeException
+	 */
+	public function foo(): void
+	{
+		throw new SomeRuntimeException();
+	}
+
+}
+
+class UnionTwo {
+
+	/**
+	 * @throws NextRuntimeException
+	 */
+	public function foo(): void
+	{
+		throw new NextRuntimeException();
+	}
+}
+
+class UnionThree {
+
+	/**
+	 * @throws ConcreteNextRuntimeException
+	 */
+	public function foo(): void
+	{
+		throw new ConcreteNextRuntimeException();
+	}
+}
+
 class Issue6
 {