[DeadCode] Fix variable usage detection

config/set/phpunit-code-quality.php

@@ -7,8 +7,6 @@ use Rector\PHPUnit\Rector\MethodCall\RemoveExpectAnyFromMockRector;
 use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
 
 return static function (ContainerConfigurator $containerConfigurator): void {
-    # [configurable]
-    # Rector\PHPUnit\Rector\Class_\ArrayArgumentInTestToDataProviderRector: null
     $services = $containerConfigurator->services();
 
     $services->set(RemoveExpectAnyFromMockRector::class);

rules/dead-code/src/NodeFinder/NextVariableUsageNodeFinder.php

@@ -6,9 +6,12 @@ namespace Rector\DeadCode\NodeFinder;
 
 use PhpParser\Node;
 use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\Variable;
 use PhpParser\NodeTraverser;
+use Rector\Core\PhpParser\Node\BetterNodeFinder;
 use Rector\Core\PhpParser\NodeTraverser\CallableNodeTraverser;
 use Rector\Core\PhpParser\Printer\BetterStandardPrinter;
+use Rector\NodeNameResolver\NodeNameResolver;
 use Rector\NodeNestingScope\ParentScopeFinder;
 use Rector\NodeTypeResolver\Node\AttributeKey;
 
@@ -29,14 +32,28 @@ final class NextVariableUsageNodeFinder
      */
     private $parentScopeFinder;
 
+    /**
+     * @var BetterNodeFinder
+     */
+    private $betterNodeFinder;
+
+    /**
+     * @var NodeNameResolver
+     */
+    private $nodeNameResolver;
+
     public function __construct(
         ParentScopeFinder $parentScopeFinder,
         CallableNodeTraverser $callableNodeTraverser,
-        BetterStandardPrinter $betterStandardPrinter
+        BetterStandardPrinter $betterStandardPrinter,
+        BetterNodeFinder $betterNodeFinder,
+        NodeNameResolver $nodeNameResolver
     ) {
         $this->callableNodeTraverser = $callableNodeTraverser;
         $this->betterStandardPrinter = $betterStandardPrinter;
         $this->parentScopeFinder = $parentScopeFinder;
+        $this->betterNodeFinder = $betterNodeFinder;
+        $this->nodeNameResolver = $nodeNameResolver;
     }
 
     public function find(Assign $assign): ?Node
@@ -46,8 +63,8 @@ final class NextVariableUsageNodeFinder
             return null;
         }
 
+        /** @var Variable $expr */
         $expr = $assign->var;
-
         $this->callableNodeTraverser->traverseNodesWithCallable((array) $scopeNode->stmts, function (Node $currentNode) use (
             $expr,
             &$nextUsageOfVariable
@@ -68,8 +85,7 @@ final class NextVariableUsageNodeFinder
 
             $currentNodeParent = $currentNode->getAttribute(AttributeKey::PARENT_NODE);
 
-            // stop at next assign
-            if ($currentNodeParent instanceof Assign) {
+            if ($currentNodeParent instanceof Assign && ! $this->hasInParentExpression($currentNodeParent, $expr)) {
                 return NodeTraverser::STOP_TRAVERSAL;
             }
 
@@ -80,4 +96,14 @@ final class NextVariableUsageNodeFinder
 
         return $nextUsageOfVariable;
     }
+
+    private function hasInParentExpression(Assign $assign, Variable $variable): bool
+    {
+        $name = $this->nodeNameResolver->getName($variable);
+        if ($name === null) {
+            return false;
+        }
+
+        return $this->betterNodeFinder->hasVariableOfName($assign->expr, $name);
+    }
 }

rules/dead-code/tests/Rector/Assign/RemoveUnusedAssignVariableRector/Fixture/skip_assign_expression_class_use_variable.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\Tests\Rector\Assign\RemoveUnusedAssignVariableRector\Fixture;
+
+final class SkipAssignExpressionClassUseVariable
+{
+    public function run()
+    {
+        $datetime = time();
+        $datetime = new \DateTime($datetime);
+        return $datetime;
+    }
+}

rules/dead-code/tests/Rector/Assign/RemoveUnusedAssignVariableRector/Fixture/skip_assign_expression_closure_use_variable.php.inc

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\Tests\Rector\Assign\RemoveUnusedAssignVariableRector\Fixture;
+
+final class SkipAssignExpressionClosureUseVariable
+{
+    public function run()
+    {
+        $content = [1, 2, 3];
+        $filtered = array_filter([1, 2, 3], function ($v) use ($content) {
+            return $content !== $v;
+        });
+        return $filtered;
+    }
+}

rules/dead-code/tests/Rector/Assign/RemoveUnusedAssignVariableRector/Fixture/skip_assign_expression_use_variable.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\Tests\Rector\Assign\RemoveUnusedAssignVariableRector\Fixture;
+
+final class SkipAssignExpressionUseValue
+{
+    public function run()
+    {
+        $content = 1;
+        $content = $content + 1;
+        return $content;
+    }
+}

rules/dead-code/tests/Rector/Assign/RemoveUnusedAssignVariableRector/Fixture/skip_assign_expression_use_variable_as_function_param.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\Tests\Rector\Assign\RemoveUnusedAssignVariableRector\Fixture;
+
+final class SkipAssignExpressionUseVariableAsFunctionParam
+{
+    public function run()
+    {
+        $content = [1, 2, 3];
+        $content = array_push($content, 1);
+        return $content;
+    }
+}

src/PhpParser/Node/BetterNodeFinder.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace Rector\Core\PhpParser\Node;
 
 use PhpParser\Node;
+use PhpParser\Node\Expr\Variable;
 use PhpParser\Node\Stmt;
 use PhpParser\Node\Stmt\Class_;
 use PhpParser\Node\Stmt\ClassLike;
@@ -12,7 +13,6 @@ use PhpParser\Node\Stmt\Expression;
 use PhpParser\NodeFinder;
 use Rector\NodeNameResolver\NodeNameResolver;
 use Rector\NodeTypeResolver\Node\AttributeKey;
-use Symfony\Component\DependencyInjection\Variable;
 
 /**
  * @see \Rector\Core\Tests\PhpParser\Node\BetterNodeFinder\BetterNodeFinderTest