[DeadCode] Add RemoveUnusedVariableAssignRector

composer.json

@@ -253,9 +253,6 @@
         "rector-ci": "bin/rector process --config rector-ci.yaml --dry-run --ansi --no-progress-bar",
         "rector": "bin/rector process --config rector-ci.yaml --ansi"
     },
-    "scripts-descriptions": {
-        "docs": "Regenerate descriptions of all Rectors to docs/AllRectorsOverview.md file"
-    },
     "config": {
         "sort-packages": true
     },

config/set/dead-code/dead-code.yaml

@@ -33,4 +33,4 @@ services:
     Rector\PHPUnit\Rector\ClassMethod\RemoveEmptyTestMethodRector: null
     Rector\DeadCode\Rector\TryCatch\RemoveDeadTryCatchRector: null
     Rector\DeadCode\Rector\ClassConst\RemoveUnusedClassConstantRector: null
-
+    Rector\DeadCode\Rector\Assign\RemoveUnusedVariableAssignRector: null

docs/AllRectorsOverview.md

@@ -1,4 +1,4 @@
-# All 461 Rectors Overview
+# All 462 Rectors Overview
 
 - [Projects](#projects)
 - [General](#general)
@@ -3115,6 +3115,25 @@ Remove unused private properties
 
 <br>
 
+### `RemoveUnusedVariableAssignRector`
+
+- class: [`Rector\DeadCode\Rector\Assign\RemoveUnusedVariableAssignRector`](/../master/rules/dead-code/src/Rector/Assign/RemoveUnusedVariableAssignRector.php)
+- [test fixtures](/../master/rules/dead-code/tests/Rector/Assign/RemoveUnusedVariableAssignRector/Fixture)
+
+Remove unused assigns to variables
+
+```diff
+ class SomeClass
+ {
+     public function run()
+     {
+-        $value = 5;
+     }
+ }
+```
+
+<br>
+
 ### `SimplifyIfElseWithSameContentRector`
 
 - class: [`Rector\DeadCode\Rector\If_\SimplifyIfElseWithSameContentRector`](/../master/rules/dead-code/src/Rector/If_/SimplifyIfElseWithSameContentRector.php)

rules/dead-code/src/Rector/Assign/RemoveUnusedVariableAssignRector.php

@@ -0,0 +1,95 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\Rector\Assign;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\Variable;
+use PhpParser\Node\FunctionLike;
+use Rector\Core\Rector\AbstractRector;
+use Rector\Core\RectorDefinition\CodeSample;
+use Rector\Core\RectorDefinition\RectorDefinition;
+use Rector\NodeTypeResolver\Node\AttributeKey;
+
+/**
+ * @see \Rector\DeadCode\Tests\Rector\Assign\RemoveUnusedVariableAssignRector\RemoveUnusedVariableAssignRectorTest
+ */
+final class RemoveUnusedVariableAssignRector extends AbstractRector
+{
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Remove unused assigns to variables', [
+            new CodeSample(
+                <<<'PHP'
+class SomeClass
+{
+    public function run()
+    {
+        $value = 5;
+    }
+}
+PHP
+,
+                <<<'PHP'
+class SomeClass
+{
+    public function run()
+    {
+    }
+}
+PHP
+
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [Assign::class];
+    }
+
+    /**
+     * @param Assign $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        $functionLike = $node->getAttribute(AttributeKey::METHOD_NODE);
+        if (! $functionLike instanceof FunctionLike) {
+            return null;
+        }
+
+        if (! $node->var instanceof Variable) {
+            return null;
+        }
+
+        // variable is used
+        $variableUsages = $this->findVariableUsages($functionLike, $node);
+        if (count($variableUsages) > 0) {
+            return null;
+        }
+
+        $this->removeNode($node);
+
+        return $node;
+    }
+
+    /**
+     * @return Variable[]
+     */
+    private function findVariableUsages(FunctionLike $functionLike, Assign $assign): array
+    {
+        return $this->betterNodeFinder->find((array) $functionLike->getStmts(), function (Node $node) use ($assign) {
+            if (! $node instanceof Variable) {
+                return false;
+            }
+
+            // skip assign value
+            return $assign->var !== $node;
+        });
+    }
+}

rules/dead-code/tests/Rector/Assign/RemoveUnusedVariableAssignRector/Fixture/fixture.php.inc

@@ -0,0 +1,26 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\Assign\RemoveUnusedVariableAssignRector\Fixture;
+
+class SomeClass
+{
+    public function run()
+    {
+        $value = 5;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\Assign\RemoveUnusedVariableAssignRector\Fixture;
+
+class SomeClass
+{
+    public function run()
+    {
+    }
+}
+
+?>

rules/dead-code/tests/Rector/Assign/RemoveUnusedVariableAssignRector/Fixture/skip_used.php.inc

@@ -0,0 +1,15 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\Assign\RemoveUnusedVariableAssignRector\Fixture;
+
+class SkipUsed
+{
+    public function run()
+    {
+        $value = 5;
+
+        if (rand(0, 10)) {
+            return $value;
+        }
+    }
+}

rules/dead-code/tests/Rector/Assign/RemoveUnusedVariableAssignRector/RemoveUnusedVariableAssignRectorTest.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\Tests\Rector\Assign\RemoveUnusedVariableAssignRector;
+
+use Iterator;
+use Rector\Core\Testing\PHPUnit\AbstractRectorTestCase;
+use Rector\DeadCode\Rector\Assign\RemoveUnusedVariableAssignRector;
+
+final class RemoveUnusedVariableAssignRectorTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideData()
+     */
+    public function test(string $file): void
+    {
+        $this->doTestFile($file);
+    }
+
+    public function provideData(): Iterator
+    {
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    protected function getRectorClass(): string
+    {
+        return RemoveUnusedVariableAssignRector::class;
+    }
+}