[TypeDeclaration] Handle union A extends B on ReturnUnionTypeRector

packages/PHPStanStaticTypeMapper/TypeMapper/UnionTypeMapper.php

@@ -35,7 +35,6 @@
 use Rector\PHPStanStaticTypeMapper\Enum\TypeKind;
 use Rector\PHPStanStaticTypeMapper\PHPStanStaticTypeMapper;
 use Rector\PHPStanStaticTypeMapper\TypeAnalyzer\UnionTypeAnalyzer;
-use Rector\PHPStanStaticTypeMapper\TypeAnalyzer\UnionTypeCommonTypeNarrower;
 use Rector\PHPStanStaticTypeMapper\ValueObject\UnionTypeAnalysis;
 use Webmozart\Assert\Assert;
 use Webmozart\Assert\InvalidArgumentException;
@@ -51,7 +50,6 @@ public function __construct(
         private readonly DoctrineTypeAnalyzer $doctrineTypeAnalyzer,
         private readonly PhpVersionProvider $phpVersionProvider,
         private readonly UnionTypeAnalyzer $unionTypeAnalyzer,
-        private readonly UnionTypeCommonTypeNarrower $unionTypeCommonTypeNarrower,
         private readonly NodeNameResolver $nodeNameResolver,
         private readonly TypeFactory $typeFactory
     ) {
@@ -282,8 +280,13 @@ private function hasObjectAndStaticType(PhpParserUnionType $phpParserUnionType):
      */
     private function matchTypeForUnionedTypes(UnionType $unionType, string $typeKind): ?Node
     {
-        $phpParserUnionType = $this->matchPhpParserUnionType($unionType, $typeKind);
+        // use first unioned type in case of unioned object types
+        $compatibleObjectTypeNode = $this->processResolveCompatibleObjectCandidates($unionType);
+        if ($compatibleObjectTypeNode instanceof NullableType || $compatibleObjectTypeNode instanceof FullyQualified) {
+            return $compatibleObjectTypeNode;
+        }
 
+        $phpParserUnionType = $this->matchPhpParserUnionType($unionType, $typeKind);
         if ($phpParserUnionType instanceof NullableType) {
             return $phpParserUnionType;
         }
@@ -292,12 +295,6 @@ private function matchTypeForUnionedTypes(UnionType $unionType, string $typeKind
             return $this->resolveUnionTypeNode($unionType, $phpParserUnionType, $typeKind);
         }
 
-        // use first unioned type in case of unioned object types
-        $compatibleObjectTypeNode = $this->processResolveCompatibleObjectCandidates($unionType);
-        if ($compatibleObjectTypeNode instanceof NullableType || $compatibleObjectTypeNode instanceof FullyQualified) {
-            return $compatibleObjectTypeNode;
-        }
-
         $type = $this->typeFactory->createMixedPassedOrUnionType($unionType->getTypes());
         if (! $type instanceof UnionType) {
             return $this->phpStanStaticTypeMapper->mapToPhpParserNode($type, $typeKind);
@@ -403,8 +400,7 @@ private function resolveCompatibleObjectCandidate(UnionType $unionType): UnionTy
             return $this->correctObjectType($sharedTypeWithClassName);
         }
 
-        // find least common denominator
-        return $this->unionTypeCommonTypeNarrower->narrowToSharedObjectType($unionType);
+        return null;
     }
 
     /**

rules-tests/TypeDeclaration/Rector/ClassMethod/ReturnUnionTypeRector/Fixture/extended_class.php.inc

@@ -0,0 +1,39 @@
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\ReturnUnionTypeRector\Fixture;
+
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\ReturnUnionTypeRector\Source\SomeParentClass;
+
+final class ExtendedClass extends SomeParentClass
+{
+    public function run()
+    {
+        if (rand(0, 1)) {
+            return new ExtendedClass();
+        }
+
+        return new SomeParentClass();
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\ReturnUnionTypeRector\Fixture;
+
+use Rector\Tests\TypeDeclaration\Rector\ClassMethod\ReturnUnionTypeRector\Source\SomeParentClass;
+
+final class ExtendedClass extends SomeParentClass
+{
+    public function run(): \Rector\Tests\TypeDeclaration\Rector\ClassMethod\ReturnUnionTypeRector\Source\SomeParentClass
+    {
+        if (rand(0, 1)) {
+            return new ExtendedClass();
+        }
+
+        return new SomeParentClass();
+    }
+}
+
+?>

rules-tests/TypeDeclaration/Rector/ClassMethod/ReturnUnionTypeRector/Source/SomeParentClass.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\TypeDeclaration\Rector\ClassMethod\ReturnUnionTypeRector\Source;
+
+class SomeParentClass
+{
+}