Too-wide return type - allow void return type in a union when the r…

…eturned expr is originally `void`

src/Rules/TooWideTypehints/TooWideFunctionReturnTypehintRule.php

@@ -56,6 +56,10 @@ public function processNode(Node $node, Scope $scope): array
 			$returnTypes[] = $returnStatement->getScope()->getType($returnNode->expr);
 		}
 
+		if (!$statementResult->isAlwaysTerminating()) {
+			$returnTypes[] = new VoidType();
+		}
+
 		$returnType = TypeCombinator::union(...$returnTypes);
 
 		$messages = [];

src/Rules/TooWideTypehints/TooWideMethodReturnTypehintRule.php

@@ -82,6 +82,10 @@ public function processNode(Node $node, Scope $scope): array
 			$returnTypes[] = $returnStatement->getScope()->getType($returnNode->expr);
 		}
 
+		if (!$statementResult->isAlwaysTerminating()) {
+			$returnTypes[] = new VoidType();
+		}
+
 		$returnType = TypeCombinator::union(...$returnTypes);
 		if (
 			!$method->isPrivate()

tests/PHPStan/Rules/TooWideTypehints/data/bug-11980-function.php

@@ -46,4 +46,25 @@ function process2($tokens, $stackPtr)
 		// Not a stand-alone statement.
 		return $end;
 	}
+
+	return 1;
+}
+
+/** @return int|void */
+function process3( int $code ) {
+
+	if ( $code === \T_CLASS ) {
+		return process_class( $code );
+	}
+
+	process_function( $code );
+}
+
+/** @return int */
+function process_class(int $code) {
+	return $code;
+}
+
+/** @return void */
+function process_function(int $code) {
 }

tests/PHPStan/Rules/TooWideTypehints/data/bug-11980.php

@@ -49,5 +49,26 @@ public function process2($tokens, $stackPtr)
 			// Not a stand-alone statement.
 			return $end;
 		}
+
+		return 1;
+	}
+
+	/** @return int|void */
+	public function process3( int $code ) {
+
+		if ( $code === \T_CLASS ) {
+			return $this->process_class( $code );
+		}
+
+		$this->process_function( $code );
+	}
+
+	/** @return int */
+	public function process_class(int $code) {
+		return $code;
+	}
+
+	/** @return void */
+	public function process_function(int $code) {
 	}
 }