Prefer exact type over mixed[] in case of empty array in ClassMethodArrayDocblockParamFromLocalCallsRector (#7334)

Author: TomasVotruba

rules-tests/TypeDeclarationDocblocks/Rector/Class_/ClassMethodArrayDocblockParamFromLocalCallsRector/Fixture/objects_overrule_empty_array.php.inc

@@ -0,0 +1,80 @@
+<?php
+
+namespace Rector\Tests\TypeDeclarationDocblocks\Rector\Class_\ClassMethodArrayDocblockParamFromLocalCallsRector\Fixture;
+
+use Rector\Tests\TypeDeclarationDocblocks\Rector\Class_\ClassMethodArrayDocblockParamFromLocalCallsRector\Source\SomeReturnedObject;
+
+final class ObjectsOverruleEmptyArray
+{
+    public function go(array $emptyArray)
+    {
+        $this->run($this->getItemsWithArray());
+        $this->run($this->getItems());
+
+        $this->run($emptyArray);
+    }
+
+    public function run(array $result)
+    {
+    }
+
+    /**
+     * @return SomeReturnedObject[]|array
+     */
+    private function getItems()
+    {
+        return [];
+    }
+
+    /**
+     * @return SomeReturnedObject[]
+     */
+    private function getItemsWithArray()
+    {
+        return [];
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\TypeDeclarationDocblocks\Rector\Class_\ClassMethodArrayDocblockParamFromLocalCallsRector\Fixture;
+
+use Rector\Tests\TypeDeclarationDocblocks\Rector\Class_\ClassMethodArrayDocblockParamFromLocalCallsRector\Source\SomeReturnedObject;
+
+final class ObjectsOverruleEmptyArray
+{
+    public function go(array $emptyArray)
+    {
+        $this->run($this->getItemsWithArray());
+        $this->run($this->getItems());
+
+        $this->run($emptyArray);
+    }
+
+    /**
+     * @param \Rector\Tests\TypeDeclarationDocblocks\Rector\Class_\ClassMethodArrayDocblockParamFromLocalCallsRector\Source\SomeReturnedObject[] $result
+     */
+    public function run(array $result)
+    {
+    }
+
+    /**
+     * @return SomeReturnedObject[]|array
+     */
+    private function getItems()
+    {
+        return [];
+    }
+
+    /**
+     * @return SomeReturnedObject[]
+     */
+    private function getItemsWithArray()
+    {
+        return [];
+    }
+}
+
+?>

rules-tests/TypeDeclarationDocblocks/Rector/Class_/ClassMethodArrayDocblockParamFromLocalCallsRector/Source/SomeReturnedObject.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace Rector\Tests\TypeDeclarationDocblocks\Rector\Class_\ClassMethodArrayDocblockParamFromLocalCallsRector\Source;
+
+final class SomeReturnedObject
+{
+}

rules/TypeDeclaration/NodeAnalyzer/CallTypesResolver.php

@@ -12,6 +12,7 @@
 use PhpParser\Node\Identifier;
 use PhpParser\Node\VariadicPlaceholder;
 use PHPStan\Reflection\ReflectionProvider;
+use PHPStan\Type\ArrayType;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\ThisType;
@@ -83,7 +84,7 @@ public function resolveTypesFromCalls(array $calls): array
         }
 
         // unite to single type
-        return $this->unionToSingleType($staticTypesByArgumentPosition);
+        return $this->unionToSingleType($staticTypesByArgumentPosition, true);
     }
 
     private function resolveStrictArgValueType(Arg $arg): Type
@@ -113,13 +114,19 @@ private function correctSelfType(Type $argValueType): Type
      * @param array<int, Type[]> $staticTypesByArgumentPosition
      * @return array<int, Type>
      */
-    private function unionToSingleType(array $staticTypesByArgumentPosition): array
+    private function unionToSingleType(array $staticTypesByArgumentPosition, bool $removeMixedArray = false): array
     {
         $staticTypeByArgumentPosition = [];
+
         foreach ($staticTypesByArgumentPosition as $position => $staticTypes) {
-            $unionedType = $this->typeFactory->createMixedPassedOrUnionType($staticTypes);
+            if ($removeMixedArray) {
+                $staticTypes = array_filter(
+                    $staticTypes,
+                    fn (Type $type): bool => ! $this->isArrayMixedMixedType($type)
+                );
+            }
 
-            // narrow parents to most child type
+            $unionedType = $this->typeFactory->createMixedPassedOrUnionType($staticTypes);
 
             $staticTypeByArgumentPosition[$position] = $this->narrowParentObjectTreeToSingleObjectChildType(
                 $unionedType
@@ -212,4 +219,17 @@ private function isEmptyArray(Expr $expr): bool
 
         return $expr->items === [];
     }
+
+    private function isArrayMixedMixedType(Type $type): bool
+    {
+        if (! $type instanceof ArrayType) {
+            return false;
+        }
+
+        if (! $type->getItemType() instanceof MixedType) {
+            return false;
+        }
+
+        return $type->getKeyType() instanceof MixedType;
+    }
 }

src/NodeTypeResolver/NodeTypeCorrector/AccessoryNonEmptyArrayTypeCorrector.php

@@ -30,7 +30,9 @@ public function correct(Type $mainType): Type
 
             if ($type instanceof ArrayType
                 && $type->getIterableValueType() instanceof IntersectionType
-                && $type->getIterableValueType()->isString()->yes()) {
+                && $type->getIterableValueType()
+                    ->isString()
+                    ->yes()) {
                 return new ArrayType(new MixedType(), new StringType());
             }
         }

src/PostRector/Collector/UseNodesToAddCollector.php

@@ -83,10 +83,8 @@ public function getUseImportTypesByNode(File $file): array
         return $objectTypes;
     }
 
-    public function hasImport(
-        File $file,
-        FullyQualifiedObjectType $fullyQualifiedObjectType
-    ): bool {
+    public function hasImport(File $file, FullyQualifiedObjectType $fullyQualifiedObjectType): bool
+    {
         $useImports = $this->getUseImportTypesByNode($file);
 
         foreach ($useImports as $useImport) {