[CodeQuality] Add indirect return scalar on ReturnTypeFromStrictScala…

…rReturnExprRector (#3478)

rules-tests/CodeQuality/Rector/ClassMethod/ReturnTypeFromStrictScalarReturnExprRector/Fixture/return_variable_string.php.inc

@@ -0,0 +1,29 @@
+<?php
+
+namespace Rector\Tests\CodeQuality\Rector\ClassMethod\ReturnTypeFromStrictScalarReturnExprRector\Fixture;
+
+final class ReturnVariableString
+{
+    public function run($value)
+    {
+        $result = $value . '/' ;
+        return $result;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\CodeQuality\Rector\ClassMethod\ReturnTypeFromStrictScalarReturnExprRector\Fixture;
+
+final class ReturnVariableString
+{
+    public function run($value): string
+    {
+        $result = $value . '/' ;
+        return $result;
+    }
+}
+
+?>

rules/TypeDeclaration/TypeAnalyzer/AlwaysStrictScalarExprAnalyzer.php

@@ -5,16 +5,22 @@
 namespace Rector\TypeDeclaration\TypeAnalyzer;
 
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\Assign;
 use PhpParser\Node\Expr\BinaryOp\Concat;
 use PhpParser\Node\Expr\ConstFetch;
 use PhpParser\Node\Expr\FuncCall;
+use PhpParser\Node\Expr\PropertyFetch;
+use PhpParser\Node\Expr\StaticPropertyFetch;
+use PhpParser\Node\Expr\Variable;
 use PhpParser\Node\Name;
 use PhpParser\Node\Scalar;
 use PhpParser\Node\Scalar\DNumber;
 use PhpParser\Node\Scalar\LNumber;
 use PhpParser\Node\Scalar\MagicConst;
 use PhpParser\Node\Scalar\MagicConst\Line;
 use PhpParser\Node\Scalar\String_;
+use PhpParser\Node\Stmt\Expression;
+use PhpParser\Node\Stmt\Return_;
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\Native\NativeFunctionReflection;
 use PHPStan\Reflection\ReflectionProvider;
@@ -25,13 +31,15 @@
 use PHPStan\Type\NullType;
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
+use Rector\Core\PhpParser\Comparing\NodeComparator;
 use Rector\NodeTypeResolver\Node\AttributeKey;
 use Rector\NodeTypeResolver\PHPStan\ParametersAcceptorSelectorVariantsWrapper;
 
 final class AlwaysStrictScalarExprAnalyzer
 {
     public function __construct(
-        private readonly ReflectionProvider $reflectionProvider
+        private readonly ReflectionProvider $reflectionProvider,
+        private readonly NodeComparator $nodeComparator
     ) {
     }
 
@@ -72,7 +80,34 @@ public function matchStrictScalarExpr(Expr $expr): ?Type
             return $returnType;
         }
 
-        return null;
+        return $this->resolveIndirectReturnType($expr);
+    }
+
+    private function resolveIndirectReturnType(Expr $expr): ?Type
+    {
+        if (! $expr instanceof Variable && ! $expr instanceof PropertyFetch && ! $expr instanceof StaticPropertyFetch) {
+            return null;
+        }
+
+        $parentNode = $expr->getAttribute(AttributeKey::PARENT_NODE);
+        if (! $parentNode instanceof Return_) {
+            return null;
+        }
+
+        $node = $parentNode->getAttribute(AttributeKey::PREVIOUS_NODE);
+        if (! $node instanceof Expression) {
+            return null;
+        }
+
+        if (! $node->expr instanceof Assign) {
+            return null;
+        }
+
+        if (! $this->nodeComparator->areNodesEqual($node->expr->var, $expr)) {
+            return null;
+        }
+
+        return $this->matchStrictScalarExpr($node->expr->expr);
     }
 
     private function isScalarType(Type $type): bool