[DeadCode] Add RemoveUnusedAssignVariableRector

composer.json

@@ -112,6 +112,7 @@
             "Rector\\Renaming\\": "rules/renaming/src",
             "Rector\\Restoration\\": "rules/restoration/src",
             "Rector\\SOLID\\": "rules/solid/src",
+            "Rector\\NodeNestingScope\\": "packages/node-nesting-scope/src",
             "Rector\\Sensio\\": "rules/sensio/src",
             "Rector\\Shopware\\": "rules/shopware/src",
             "Rector\\Silverstripe\\": "rules/silverstripe/src",

docs/AllRectorsOverview.md

@@ -1,4 +1,4 @@
-# All 482 Rectors Overview
+# All 483 Rectors Overview
 
 - [Projects](#projects)
 - [General](#general)
@@ -3001,6 +3001,32 @@ Remove unreachable statements
 
 <br>
 
+### `RemoveUnusedAssignVariableRector`
+
+- class: [`Rector\DeadCode\Rector\Assign\RemoveUnusedAssignVariableRector`](/../master/rules/dead-code/src/Rector/Assign/RemoveUnusedAssignVariableRector.php)
+- [test fixtures](/../master/rules/dead-code/tests/Rector/Assign/RemoveUnusedAssignVariableRector/Fixture)
+
+Remove assigned unused variable
+
+```diff
+ class SomeClass
+ {
+     public function run()
+     {
+-        $value = $this->process();
++        $this->process();
+     }
+
+     public function process()
+     {
+         // something going on
+         return 5;
+     }
+ }
+```
+
+<br>
+
 ### `RemoveUnusedClassConstantRector`
 
 - class: [`Rector\DeadCode\Rector\ClassConst\RemoveUnusedClassConstantRector`](/../master/rules/dead-code/src/Rector/ClassConst/RemoveUnusedClassConstantRector.php)

packages/node-nesting-scope/config/config.yaml

@@ -0,0 +1,8 @@
+services:
+    _defaults:
+        public: true
+        autowire: true
+        autoconfigure: true
+
+    Rector\NodeNestingScope\:
+        resource: '../src'

rules/dead-code/src/FlowOfControlLocator.php → packages/node-nesting-scope/src/FlowOfControlLocator.php

@@ -2,7 +2,7 @@
 
 declare(strict_types=1);
 
-namespace Rector\DeadCode;
+namespace Rector\NodeNestingScope;
 
 use PhpParser\Node;
 use PhpParser\Node\FunctionLike;

packages/node-nesting-scope/src/ParentScopeFinder.php

@@ -0,0 +1,26 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\NodeNestingScope;
+
+use PhpParser\Node;
+use PhpParser\Node\Stmt\Class_;
+use PhpParser\Node\Stmt\ClassMethod;
+use PhpParser\Node\Stmt\Function_;
+use PhpParser\Node\Stmt\Namespace_;
+use Rector\NodeTypeResolver\Node\AttributeKey;
+
+final class ParentScopeFinder
+{
+    /**
+     * @return ClassMethod|Function_|Class_|Namespace_|null
+     */
+    public function find(Node $node): ?Node
+    {
+        return $node->getAttribute(AttributeKey::METHOD_NODE)
+            ?? $node->getAttribute(AttributeKey::FUNCTION_NODE)
+            ?? $node->getAttribute(AttributeKey::CLASS_NODE)
+            ?? $node->getAttribute(AttributeKey::NAMESPACE_NODE);
+    }
+}

packages/node-nesting-scope/src/ScopeNestingComparator.php

@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\NodeNestingScope;
+
+use PhpParser\Node;
+use PhpParser\Node\FunctionLike;
+use PhpParser\Node\Stmt\Case_;
+use PhpParser\Node\Stmt\Catch_;
+use PhpParser\Node\Stmt\Do_;
+use PhpParser\Node\Stmt\Else_;
+use PhpParser\Node\Stmt\ElseIf_;
+use PhpParser\Node\Stmt\For_;
+use PhpParser\Node\Stmt\Foreach_;
+use PhpParser\Node\Stmt\If_;
+use PhpParser\Node\Stmt\While_;
+use Rector\Core\PhpParser\Node\BetterNodeFinder;
+
+final class ScopeNestingComparator
+{
+    /**
+     * @var class-string[]
+     */
+    private const CONTROL_STRUCTURE_NODES = [
+        For_::class,
+        Foreach_::class,
+        If_::class,
+        While_::class,
+        Do_::class,
+        Else_::class,
+        ElseIf_::class,
+        Catch_::class,
+        Case_::class,
+        FunctionLike::class,
+    ];
+
+    /**
+     * @var BetterNodeFinder
+     */
+    private $betterNodeFinder;
+
+    public function __construct(BetterNodeFinder $betterNodeFinder)
+    {
+        $this->betterNodeFinder = $betterNodeFinder;
+    }
+
+    public function areScopeNestingEqual(Node $firstNode, Node $secondNode): bool
+    {
+        $firstNodeScopeNode = $this->findParentControlStructure($firstNode);
+        $secondNodeScopeNode = $this->findParentControlStructure($secondNode);
+
+        return $firstNodeScopeNode === $secondNodeScopeNode;
+    }
+
+    private function findParentControlStructure(Node $node): ?Node
+    {
+        return $this->betterNodeFinder->findFirstParentInstanceOf($node, self::CONTROL_STRUCTURE_NODES);
+    }
+}

packages/node-type-resolver/src/NodeTypeCorrector/PregMatchTypeCorrector.php

@@ -14,6 +14,7 @@
 use Rector\Core\PhpParser\Node\BetterNodeFinder;
 use Rector\Core\PhpParser\Printer\BetterStandardPrinter;
 use Rector\NodeNameResolver\NodeNameResolver;
+use Rector\NodeNestingScope\ParentScopeFinder;
 use Rector\NodeTypeResolver\Node\AttributeKey;
 
 final class PregMatchTypeCorrector
@@ -33,14 +34,21 @@ final class PregMatchTypeCorrector
      */
     private $betterStandardPrinter;
 
+    /**
+     * @var ParentScopeFinder
+     */
+    private $parentScopeFinder;
+
     public function __construct(
         BetterNodeFinder $betterNodeFinder,
         NodeNameResolver $nodeNameResolver,
-        BetterStandardPrinter $betterStandardPrinter
+        BetterStandardPrinter $betterStandardPrinter,
+        ParentScopeFinder $parentScopeFinder
     ) {
         $this->betterNodeFinder = $betterNodeFinder;
         $this->nodeNameResolver = $nodeNameResolver;
         $this->betterStandardPrinter = $betterStandardPrinter;
+        $this->parentScopeFinder = $parentScopeFinder;
     }
 
     /**
@@ -93,8 +101,7 @@ public function correct(Node $node, Type $originalType): Type
      */
     private function getVariableUsages(Variable $variable): array
     {
-        $scope = $this->getScopeNode($variable);
-
+        $scope = $this->parentScopeFinder->find($variable);
         if ($scope === null) {
             return [];
         }
@@ -103,11 +110,4 @@ private function getVariableUsages(Variable $variable): array
             return $node instanceof Variable && $node->name === $variable->name;
         });
     }
-
-    private function getScopeNode(Node $node): ?Node
-    {
-        return $node->getAttribute(AttributeKey::METHOD_NODE)
-            ?? $node->getAttribute(AttributeKey::FUNCTION_NODE)
-            ?? $node->getAttribute(AttributeKey::NAMESPACE_NODE);
-    }
 }

phpstan.neon

@@ -95,10 +95,6 @@ parameters:
         # node finder
         - '#Method Rector\\(.*?) should return array<PhpParser\\Node\\(.*?)> but returns array<PhpParser\\Node\>#'
 
-        # known values
-        - '#Parameter \#2 \$variableName of class Rector\\DeadCode\\Data\\VariableNodeUseInfo constructor expects string, string\|null given#'
-        - '#Cannot call method getParentNode\(\) on Rector\\DeadCode\\Data\\VariableNodeUseInfo\|null#'
-
         # part of test
         - '#(.*?)(AttributeAwareNodeInterface|AttributeAware(.*?)TagValueNode)(.*?)#'
 
@@ -255,10 +251,12 @@ parameters:
         - '#Method Rector\\BetterPhpDocParser\\AnnotationReader\\NodeAnnotationReader\:\:createClassReflectionFromNode\(\) return type with generic class ReflectionClass does not specify its types\: T#'
         - '#Method Rector\\NodeCollector\\StaticAnalyzer\:\:hasStaticAnnotation\(\) has parameter \$reflectionClass with generic class ReflectionClass but does not specify its types\: T#'
 
-        - '#Method Rector\\BetterPhpDocParser\\AnnotationReader\\AnnotationReaderFactory\:\:create\(\) should return Doctrine\\Common\\Annotations\\Reader but returns Doctrine\\Common\\Annotations\\AnnotationReader\|Rector\\DoctrineAnnotationGenerated\\ConstantPreservingAnnotationReader#'
-
         # mixed
         - '#Property Rector\\Polyfill\\ValueObject\\BinaryToVersionCompareCondition\:\:\$expectedValue has no typehint specified#'
         # node finder
         - '#Method Rector\\Core\\PhpParser\\Node\\Manipulator\\MethodCallManipulator\:\:findAssignToVariableName\(\) should return PhpParser\\Node\\Expr\\Assign\|null but returns PhpParser\\Node\|null#'
 
+        # broken
+        - '#Cannot call method getParentNode\(\) on Rector\\DeadCode\\ValueObject\\VariableNodeUse\|null#'
+        - '#Method Rector\\DeadCode\\NodeFinder\\PreviousVariableAssignNodeFinder\:\:find\(\) should return PhpParser\\Node\\Expr\\Assign\|null but returns PhpParser\\Node\|null#'
+        - '#Parameter \#2 \$name of method Rector\\NodeNameResolver\\NodeNameResolver\:\:isName\(\) expects string, string\|null given#'

rules/dead-code/config/config.yaml

@@ -7,4 +7,4 @@ services:
         resource: '../src'
         exclude:
             - '../src/Rector/**/*Rector.php'
-            - '../src/Data/*'
+            - '../src/ValueObject/*'

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

@@ -0,0 +1,83 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\NodeFinder;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Assign;
+use PhpParser\NodeTraverser;
+use Rector\Core\PhpParser\NodeTraverser\CallableNodeTraverser;
+use Rector\Core\PhpParser\Printer\BetterStandardPrinter;
+use Rector\NodeNestingScope\ParentScopeFinder;
+use Rector\NodeTypeResolver\Node\AttributeKey;
+
+final class NextVariableUsageNodeFinder
+{
+    /**
+     * @var CallableNodeTraverser
+     */
+    private $callableNodeTraverser;
+
+    /**
+     * @var BetterStandardPrinter
+     */
+    private $betterStandardPrinter;
+
+    /**
+     * @var ParentScopeFinder
+     */
+    private $parentScopeFinder;
+
+    public function __construct(
+        ParentScopeFinder $parentScopeFinder,
+        CallableNodeTraverser $callableNodeTraverser,
+        BetterStandardPrinter $betterStandardPrinter
+    ) {
+        $this->callableNodeTraverser = $callableNodeTraverser;
+        $this->betterStandardPrinter = $betterStandardPrinter;
+        $this->parentScopeFinder = $parentScopeFinder;
+    }
+
+    public function find(Assign $assign): ?Node
+    {
+        $scopeNode = $this->parentScopeFinder->find($assign);
+        if ($scopeNode === null) {
+            return null;
+        }
+
+        $expr = $assign->var;
+
+        $this->callableNodeTraverser->traverseNodesWithCallable((array) $scopeNode->stmts, function (Node $currentNode) use (
+            $expr,
+            &$nextUsageOfVariable
+        ) {
+            // used above the assign
+            if ($currentNode->getStartTokenPos() < $expr->getStartTokenPos()) {
+                return null;
+            }
+
+            // skip self
+            if ($currentNode === $expr) {
+                return null;
+            }
+
+            if (! $this->betterStandardPrinter->areNodesEqual($currentNode, $expr)) {
+                return null;
+            }
+
+            $currentNodeParent = $currentNode->getAttribute(AttributeKey::PARENT_NODE);
+
+            // stop at next assign
+            if ($currentNodeParent instanceof Assign) {
+                return NodeTraverser::STOP_TRAVERSAL;
+            }
+
+            $nextUsageOfVariable = $currentNode;
+
+            return NodeTraverser::STOP_TRAVERSAL;
+        });
+
+        return $nextUsageOfVariable;
+    }
+}

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

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\NodeFinder;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Assign;
+use Rector\Core\PhpParser\Node\BetterNodeFinder;
+use Rector\NodeNameResolver\NodeNameResolver;
+
+final class PreviousVariableAssignNodeFinder
+{
+    /**
+     * @var BetterNodeFinder
+     */
+    private $betterNodeFinder;
+
+    /**
+     * @var NodeNameResolver
+     */
+    private $nodeNameResolver;
+
+    public function __construct(BetterNodeFinder $betterNodeFinder, NodeNameResolver $nodeNameResolver)
+    {
+        $this->betterNodeFinder = $betterNodeFinder;
+        $this->nodeNameResolver = $nodeNameResolver;
+    }
+
+    public function find(Assign $assign): ?Assign
+    {
+        $currentAssign = $assign;
+        $variableName = $this->nodeNameResolver->getName($assign->var);
+
+        return $this->betterNodeFinder->findFirstPrevious($assign, function (Node $node) use (
+            $variableName,
+            $currentAssign
+        ): bool {
+            if (! $node instanceof Assign) {
+                return false;
+            }
+
+            // skil self
+            if ($node === $currentAssign) {
+                return false;
+            }
+
+            return $this->nodeNameResolver->isName($node->var, $variableName);
+        });
+    }
+}