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;
+}
+}
+}