From ceb493065c7bfaf39cc61d5fa8358b064ef568cd Mon Sep 17 00:00:00 2001
From: Abdul Malik Ikhsan <samsonasik@gmail.com>
Date: Fri, 20 Aug 2021 22:32:12 +0700
Subject: [PATCH] [DowngradePhp80] Remove self return type if child already has
 no return type (#725)

* [DowngradePhp80] Remove self return type if child already has no return type

* comment

* fix

* clean up

* phpstan
---
 phpstan.neon                                  | 10 ++++
 ..._self_child_already_no_return_type.php.inc | 44 ++++++++++++++
 .../DowngradeStaticTypeDeclarationRector.php  | 59 +++++++++++++++++--
 3 files changed, 108 insertions(+), 5 deletions(-)
 create mode 100644 rules-tests/DowngradePhp80/Rector/ClassMethod/DowngradeStaticTypeDeclarationRector/Fixture/remove_self_child_already_no_return_type.php.inc

diff --git a/phpstan.neon b/phpstan.neon
index aa32cfd2274..84d3078285a 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -528,3 +528,13 @@ parameters:
             paths:
                  - rules/Php72/Rector/Assign/ReplaceEachAssignmentWithKeyCurrentRector.php
 
+        -
+            message: '#foreach\(\), while\(\), for\(\) or if\(\) cannot contain a complex expression\. Extract it to a new variable on a line before#'
+            paths:
+                - packages/NodeNestingScope/FlowOfControlLocator.php
+                - packages/NodeNestingScope/ParentFinder.php
+                - rules/CodeQuality/Rector/Return_/SimplifyUselessVariableRector.php
+                - rules/CodingStyle/Rector/Assign/ManualJsonStringToJsonEncodeArrayRector.php
+                - rules/Php70/Rector/FuncCall/MultiDirnameRector.php
+                - src/Application/FileProcessor.php
+                - src/PhpParser/Node/BetterNodeFinder.php
diff --git a/rules-tests/DowngradePhp80/Rector/ClassMethod/DowngradeStaticTypeDeclarationRector/Fixture/remove_self_child_already_no_return_type.php.inc b/rules-tests/DowngradePhp80/Rector/ClassMethod/DowngradeStaticTypeDeclarationRector/Fixture/remove_self_child_already_no_return_type.php.inc
new file mode 100644
index 00000000000..693018536df
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/ClassMethod/DowngradeStaticTypeDeclarationRector/Fixture/remove_self_child_already_no_return_type.php.inc
@@ -0,0 +1,44 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\ClassMethod\DowngradeStaticTypeDeclarationRector\Fixture;
+
+interface RemoveSelfChildAlreadyNoType
+{
+    public function run(): self;
+}
+
+class Child implements RemoveSelfChildAlreadyNoType
+{
+    // return type may removed by other rules
+    // @see https://github.com/rectorphp/rector/issues/6652
+    public function run()
+    {
+
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\ClassMethod\DowngradeStaticTypeDeclarationRector\Fixture;
+
+interface RemoveSelfChildAlreadyNoType
+{
+    /**
+     * @return $this
+     */
+    public function run();
+}
+
+class Child implements RemoveSelfChildAlreadyNoType
+{
+    // return type may removed by other rules
+    // @see https://github.com/rectorphp/rector/issues/6652
+    public function run()
+    {
+
+    }
+}
+
+?>
diff --git a/rules/DowngradePhp80/Rector/ClassMethod/DowngradeStaticTypeDeclarationRector.php b/rules/DowngradePhp80/Rector/ClassMethod/DowngradeStaticTypeDeclarationRector.php
index 02489cc5e91..d33cee07176 100644
--- a/rules/DowngradePhp80/Rector/ClassMethod/DowngradeStaticTypeDeclarationRector.php
+++ b/rules/DowngradePhp80/Rector/ClassMethod/DowngradeStaticTypeDeclarationRector.php
@@ -7,11 +7,14 @@
 use PhpParser\Node;
 use PhpParser\Node\Name;
 use PhpParser\Node\Stmt\ClassMethod;
+use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\ClassReflection;
 use PHPStan\Reflection\ReflectionProvider;
 use PHPStan\Type\StaticType;
+use Rector\Core\PhpParser\AstResolver;
 use Rector\Core\Rector\AbstractRector;
 use Rector\DowngradePhp71\TypeDeclaration\PhpDocFromTypeDeclarationDecorator;
+use Rector\FamilyTree\Reflection\FamilyRelationsAnalyzer;
 use Rector\NodeTypeResolver\Node\AttributeKey;
 use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
 use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
@@ -23,7 +26,9 @@ final class DowngradeStaticTypeDeclarationRector extends AbstractRector
 {
     public function __construct(
         private PhpDocFromTypeDeclarationDecorator $phpDocFromTypeDeclarationDecorator,
-        private ReflectionProvider $reflectionProvider
+        private ReflectionProvider $reflectionProvider,
+        private AstResolver $astResolver,
+        private FamilyRelationsAnalyzer $familyRelationsAnalyzer
     ) {
     }
 
@@ -73,10 +78,9 @@ public function getStatic()
      */
     public function refactor(Node $node): ?Node
     {
-        if ($node->returnType instanceof Name && $this->nodeNameResolver->isName(
-            $node->returnType,
-            'self'
-        )) {
+        $scope = $node->getAttribute(AttributeKey::SCOPE);
+
+        if ($scope instanceof Scope && $this->shouldSkip($node, $scope)) {
             return null;
         }
 
@@ -104,4 +108,49 @@ public function refactor(Node $node): ?Node
 
         return $node;
     }
+
+    private function shouldSkip(ClassMethod $classMethod, Scope $scope): bool
+    {
+        if (! $classMethod->returnType instanceof Name) {
+            return false;
+        }
+
+        if (! $this->nodeNameResolver->isName($classMethod->returnType, 'self')) {
+            return false;
+        }
+
+        $classLike = $classMethod->getAttribute(AttributeKey::CLASS_NODE);
+        $className = $this->nodeNameResolver->getName($classLike);
+
+        if ($className === null) {
+            return false;
+        }
+
+        if (! $this->reflectionProvider->hasClass($className)) {
+            return false;
+        }
+
+        $classReflection = $this->reflectionProvider->getClass($className);
+        $methodName = $this->nodeNameResolver->getName($classMethod);
+        $children = $this->familyRelationsAnalyzer->getChildrenOfClassReflection($classReflection);
+
+        foreach ($children as $child) {
+            if (! $child->hasMethod($methodName)) {
+                continue;
+            }
+
+            $method = $child->getMethod($methodName, $scope);
+            $classMethod = $this->astResolver->resolveClassMethodFromMethodReflection($method);
+
+            if (! $classMethod instanceof ClassMethod) {
+                continue;
+            }
+
+            if ($classMethod->returnType === null) {
+                return false;
+            }
+        }
+
+        return true;
+    }
 }