Too-wide return type - do not report void in PHPDoc union type

Author: ondrejmirtes

src/Rules/TooWideTypehints/TooWideFunctionReturnTypehintRule.php

@@ -11,6 +11,7 @@
 use PHPStan\Type\TypeUtils;
 use PHPStan\Type\UnionType;
 use PHPStan\Type\VerbosityLevel;
+use PHPStan\Type\VoidType;
 use function count;
 use function sprintf;
 
@@ -48,16 +49,13 @@ public function processNode(Node $node, Scope $scope): array
 		foreach ($returnStatements as $returnStatement) {
 			$returnNode = $returnStatement->getReturnNode();
 			if ($returnNode->expr === null) {
+				$returnTypes[] = new VoidType();
 				continue;
 			}
 
 			$returnTypes[] = $returnStatement->getScope()->getType($returnNode->expr);
 		}
 
-		if (count($returnTypes) === 0) {
-			return [];
-		}
-
 		$returnType = TypeCombinator::union(...$returnTypes);
 
 		$messages = [];

src/Rules/TooWideTypehints/TooWideMethodReturnTypehintRule.php

@@ -12,6 +12,7 @@
 use PHPStan\Type\TypeUtils;
 use PHPStan\Type\UnionType;
 use PHPStan\Type\VerbosityLevel;
+use PHPStan\Type\VoidType;
 use function count;
 use function sprintf;
 
@@ -74,16 +75,13 @@ public function processNode(Node $node, Scope $scope): array
 		foreach ($returnStatements as $returnStatement) {
 			$returnNode = $returnStatement->getReturnNode();
 			if ($returnNode->expr === null) {
+				$returnTypes[] = new VoidType();
 				continue;
 			}
 
 			$returnTypes[] = $returnStatement->getScope()->getType($returnNode->expr);
 		}
 
-		if (count($returnTypes) === 0) {
-			return [];
-		}
-
 		$returnType = TypeCombinator::union(...$returnTypes);
 		if (
 			!$method->isPrivate()

tests/PHPStan/Rules/TooWideTypehints/TooWideFunctionReturnTypehintRuleTest.php

@@ -51,4 +51,14 @@ public function testRule(): void
 		]);
 	}
 
+	public function testBug11980(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-11980-function.php'], [
+			[
+				'Function Bug11980Function\process2() never returns void so it can be removed from the return type.',
+				34,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/TooWideTypehints/TooWideMethodReturnTypehintRuleTest.php

@@ -248,4 +248,16 @@ public function testAlwaysCheckFinal(bool $checkProtectedAndPublicMethods, bool
 		$this->analyse([__DIR__ . '/data/method-too-wide-return-always-check-final.php'], $expectedErrors);
 	}
 
+	public function testBug11980(): void
+	{
+		$this->checkProtectedAndPublicMethods = true;
+		$this->alwaysCheckFinal = true;
+		$this->analyse([__DIR__ . '/data/bug-11980.php'], [
+			[
+				'Method Bug11980\Demo::process2() never returns void so it can be removed from the return type.',
+				37,
+			],
+		]);
+	}
+
 }

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

@@ -0,0 +1,49 @@
+<?php
+
+namespace Bug11980Function;
+
+/**
+ * @param array<int, array<string, int>> $tokens
+ * @param int                            $stackPtr
+ *
+ * @return int|void
+ */
+function process($tokens, $stackPtr)
+{
+	if (empty($tokens[$stackPtr]['nested_parenthesis']) === false) {
+		// Not a stand-alone statement.
+		return;
+	}
+
+	$end = 10;
+
+	if ($tokens[$end]['code'] !== 10
+		&& $tokens[$end]['code'] !== 20
+	) {
+		// Not a stand-alone statement.
+		return $end;
+	}
+}
+
+/**
+ * @param array<int, array<string, int>> $tokens
+ * @param int                            $stackPtr
+ *
+ * @return int|void
+ */
+function process2($tokens, $stackPtr)
+{
+	if (empty($tokens[$stackPtr]['nested_parenthesis']) === false) {
+		// Not a stand-alone statement.
+		return null;
+	}
+
+	$end = 10;
+
+	if ($tokens[$end]['code'] !== 10
+		&& $tokens[$end]['code'] !== 20
+	) {
+		// Not a stand-alone statement.
+		return $end;
+	}
+}

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

@@ -0,0 +1,53 @@
+<?php
+
+namespace Bug11980;
+
+final class Demo
+{
+
+	/**
+	 * @param array<int, array<string, int>> $tokens
+	 * @param int                            $stackPtr
+	 *
+	 * @return int|void
+	 */
+	public function process($tokens, $stackPtr)
+	{
+		if (empty($tokens[$stackPtr]['nested_parenthesis']) === false) {
+			// Not a stand-alone statement.
+			return;
+		}
+
+		$end = 10;
+
+		if ($tokens[$end]['code'] !== 10
+			&& $tokens[$end]['code'] !== 20
+		) {
+			// Not a stand-alone statement.
+			return $end;
+		}
+	}
+
+	/**
+	 * @param array<int, array<string, int>> $tokens
+	 * @param int                            $stackPtr
+	 *
+	 * @return int|void
+	 */
+	public function process2($tokens, $stackPtr)
+	{
+		if (empty($tokens[$stackPtr]['nested_parenthesis']) === false) {
+			// Not a stand-alone statement.
+			return null;
+		}
+
+		$end = 10;
+
+		if ($tokens[$end]['code'] !== 10
+			&& $tokens[$end]['code'] !== 20
+		) {
+			// Not a stand-alone statement.
+			return $end;
+		}
+	}
+}