[DeadCode] Add RemoveJustPropertyFetchForAssignRector (#2423)

build/target-repository/docs/rector_rules_overview.md

@@ -1,4 +1,4 @@
-# 516 Rules Overview
+# 517 Rules Overview
 
 <br>
 
@@ -14,7 +14,7 @@
 
 - [Composer](#composer) (6)
 
-- [DeadCode](#deadcode) (48)
+- [DeadCode](#deadcode) (49)
 
 - [DependencyInjection](#dependencyinjection) (2)
 
@@ -3230,6 +3230,29 @@ Remove empty method call
 
 <br>
 
+### RemoveJustPropertyFetchForAssignRector
+
+Remove assign of property, just for value assign
+
+- class: [`Rector\DeadCode\Rector\StmtsAwareInterface\RemoveJustPropertyFetchForAssignRector`](../rules/DeadCode/Rector/StmtsAwareInterface/RemoveJustPropertyFetchForAssignRector.php)
+
+```diff
+ class SomeClass
+ {
+     private $items = [];
+
+     public function run()
+     {
+-        $items = $this->items;
+-        $items[] = 1000;
+-        $this->items = $items ;
++        $this->items[] = 1000;
+     }
+ }
+```
+
+<br>
+
 ### RemoveLastReturnRector
 
 Remove very last `return` that has no meaning

config/set/dead-code.php

@@ -44,6 +44,7 @@
 use Rector\DeadCode\Rector\Return_\RemoveDeadConditionAboveReturnRector;
 use Rector\DeadCode\Rector\StaticCall\RemoveParentCallWithoutParentRector;
 use Rector\DeadCode\Rector\Stmt\RemoveUnreachableStatementRector;
+use Rector\DeadCode\Rector\StmtsAwareInterface\RemoveJustPropertyFetchForAssignRector;
 use Rector\DeadCode\Rector\Switch_\RemoveDuplicatedCaseInSwitchRector;
 use Rector\DeadCode\Rector\Ternary\TernaryToBooleanOrFalseToBooleanAndRector;
 use Rector\DeadCode\Rector\TryCatch\RemoveDeadTryCatchRector;
@@ -97,5 +98,6 @@
         RemoveNonExistingVarAnnotationRector::class,
         RemoveUnusedPromotedPropertyRector::class,
         RemoveLastReturnRector::class,
+        RemoveJustPropertyFetchForAssignRector::class,
     ]);
 };

phpstan.neon

@@ -712,3 +712,8 @@ parameters:
         -
             message: '#Method "refactor(Params|Return)\(\)" returns bool type, so the name should start with is/has/was#'
             path: rules/Php80/Rector/Class_/ConstantListClassToEnumRector.php
+
+        # known values
+        -
+            message:  '#Offset \d+ does not exist on array<PhpParser\\Node\\Stmt>\|null#'
+            path: rules/DeadCode/Rector/StmtsAwareInterface/RemoveJustPropertyFetchForAssignRector.php

rules-tests/DeadCode/Rector/StmtsAwareInterface/RemoveJustPropertyFetchForAssignRector/Fixture/skip_different_property_fetch.php.inc

@@ -0,0 +1,17 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\StmtsAwareInterface\RemoveJustPropertyFetchForAssignRector\Fixture;
+
+final class SkipDifferentPropertyFetch
+{
+    private $items = [];
+
+    private $another = [];
+
+    public function run()
+    {
+        $items = $this->another;
+        $items[] = 1000;
+        $this->items = $items ;
+    }
+}

rules-tests/DeadCode/Rector/StmtsAwareInterface/RemoveJustPropertyFetchForAssignRector/Fixture/skip_different_variable.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\StmtsAwareInterface\RemoveJustPropertyFetchForAssignRector\Fixture;
+
+final class SkipDifferentVariable
+{
+    private $items = [];
+
+    public function run()
+    {
+        $items = $this->items;
+        $items[] = 1000;
+        $this->items = $items2;
+    }
+}

rules-tests/DeadCode/Rector/StmtsAwareInterface/RemoveJustPropertyFetchForAssignRector/Fixture/skip_four_stmts.php.inc

@@ -0,0 +1,16 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\StmtsAwareInterface\RemoveJustPropertyFetchForAssignRector\Fixture;
+
+final class SkipFourStmts
+{
+    private $items = [];
+
+    public function run()
+    {
+        $items = $this->items;
+        $items[] = 1000;
+        $items[] = 1000;
+        $this->items = $items ;
+    }
+}

rules-tests/DeadCode/Rector/StmtsAwareInterface/RemoveJustPropertyFetchForAssignRector/Fixture/some_class.php.inc

@@ -0,0 +1,33 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\StmtsAwareInterface\RemoveJustPropertyFetchForAssignRector\Fixture;
+
+class SomeClass
+{
+    private $items = [];
+
+    public function run()
+    {
+        $items = $this->items;
+        $items[] = 1000;
+        $this->items = $items ;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\StmtsAwareInterface\RemoveJustPropertyFetchForAssignRector\Fixture;
+
+class SomeClass
+{
+    private $items = [];
+
+    public function run()
+    {
+        $this->items[] = 1000;
+    }
+}
+
+?>

rules-tests/DeadCode/Rector/StmtsAwareInterface/RemoveJustPropertyFetchForAssignRector/RemoveJustPropertyFetchForAssignRectorTest.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\DeadCode\Rector\StmtsAwareInterface\RemoveJustPropertyFetchForAssignRector;
+
+use Iterator;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+use Symplify\SmartFileSystem\SmartFileInfo;
+
+final class RemoveJustPropertyFetchForAssignRectorTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideData()
+     */
+    public function test(SmartFileInfo $fileInfo): void
+    {
+        $this->doTestFileInfo($fileInfo);
+    }
+
+    /**
+     * @return Iterator<SmartFileInfo>
+     */
+    public function provideData(): Iterator
+    {
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}

rules-tests/DeadCode/Rector/StmtsAwareInterface/RemoveJustPropertyFetchForAssignRector/config/configured_rule.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\DeadCode\Rector\StmtsAwareInterface\RemoveJustPropertyFetchForAssignRector;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->rule(RemoveJustPropertyFetchForAssignRector::class);
+};

rules/DeadCode/NodeAnalyzer/JustPropertyFetchVariableAssignMatcher.php

@@ -0,0 +1,104 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\NodeAnalyzer;
+
+use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\PropertyFetch;
+use PhpParser\Node\Expr\Variable;
+use PhpParser\Node\Stmt;
+use PhpParser\Node\Stmt\Expression;
+use Rector\Core\Contract\PhpParser\Node\StmtsAwareInterface;
+use Rector\Core\PhpParser\Comparing\NodeComparator;
+use Rector\DeadCode\ValueObject\VariableAndPropertyFetchAssign;
+
+final class JustPropertyFetchVariableAssignMatcher
+{
+    public function __construct(
+        private readonly NodeComparator $nodeComparator
+    ) {
+    }
+
+    public function match(StmtsAwareInterface $stmtsAware): ?VariableAndPropertyFetchAssign
+    {
+        $stmts = (array) $stmtsAware->stmts;
+
+        $stmtCount = count($stmts);
+
+        // must be exactly 3 stmts
+        if ($stmtCount !== 3) {
+            return null;
+        }
+
+        $firstVariableAndPropertyFetchAssign = $this->matchVariableAndPropertyFetchAssign($stmts[0]);
+        if (! $firstVariableAndPropertyFetchAssign instanceof VariableAndPropertyFetchAssign) {
+            return null;
+        }
+
+        $thirdVariableAndPropertyFetchAssign = $this->matchRevertedVariableAndPropertyFetchAssign($stmts[2]);
+        if (! $thirdVariableAndPropertyFetchAssign instanceof VariableAndPropertyFetchAssign) {
+            return null;
+        }
+
+        if (! $this->nodeComparator->areNodesEqual(
+            $firstVariableAndPropertyFetchAssign->getPropertyFetch(),
+            $thirdVariableAndPropertyFetchAssign->getPropertyFetch()
+        )) {
+            return null;
+        }
+
+        if (! $this->nodeComparator->areNodesEqual(
+            $firstVariableAndPropertyFetchAssign->getVariable(),
+            $thirdVariableAndPropertyFetchAssign->getVariable()
+        )) {
+            return null;
+        }
+
+        return $firstVariableAndPropertyFetchAssign;
+    }
+
+    private function matchVariableAndPropertyFetchAssign(Stmt $stmt): ?VariableAndPropertyFetchAssign
+    {
+        if (! $stmt instanceof Expression) {
+            return null;
+        }
+
+        if (! $stmt->expr instanceof Assign) {
+            return null;
+        }
+
+        $assign = $stmt->expr;
+        if (! $assign->expr instanceof PropertyFetch) {
+            return null;
+        }
+
+        if (! $assign->var instanceof Variable) {
+            return null;
+        }
+
+        return new VariableAndPropertyFetchAssign($assign->var, $assign->expr);
+    }
+
+    private function matchRevertedVariableAndPropertyFetchAssign(Stmt $stmt): ?VariableAndPropertyFetchAssign
+    {
+        if (! $stmt instanceof Expression) {
+            return null;
+        }
+
+        if (! $stmt->expr instanceof Assign) {
+            return null;
+        }
+
+        $assign = $stmt->expr;
+        if (! $assign->var instanceof PropertyFetch) {
+            return null;
+        }
+
+        if (! $assign->expr instanceof Variable) {
+            return null;
+        }
+
+        return new VariableAndPropertyFetchAssign($assign->expr, $assign->var);
+    }
+}