[DeadCode] Add RemoveUnusedClassConstantRector

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

@@ -32,4 +32,4 @@ services:
     Rector\DeadCode\Rector\Ternary\TernaryToBooleanOrFalseToBooleanAndRector: null
     Rector\PHPUnit\Rector\ClassMethod\RemoveEmptyTestMethodRector: null
     Rector\DeadCode\Rector\TryCatch\RemoveDeadTryCatchRector: null
-
+    Rector\DeadCode\Rector\ClassConst\RemoveUnusedClassConstantRector: null

docs/AllRectorsOverview.md

@@ -1,4 +1,4 @@
-# All 460 Rectors Overview
+# All 461 Rectors Overview
 
 - [Projects](#projects)
 - [General](#general)
@@ -351,12 +351,13 @@ Changes method calls based on matching the first parameter value.
 ```yaml
 services:
     Rector\CakePHP\Rector\MethodCall\RenameMethodCallBasedOnParameterRector:
-        getParam:
-            match_parameter: paging
-            replace_with: getAttribute
-        withParam:
-            match_parameter: paging
-            replace_with: withAttribute
+        $methodNamesByTypes:
+            getParam:
+                match_parameter: paging
+                replace_with: getAttribute
+            withParam:
+                match_parameter: paging
+                replace_with: withAttribute
 ```
 
 ↓
@@ -2936,6 +2937,26 @@ Remove unreachable statements
 
 <br>
 
+### `RemoveUnusedClassConstantRector`
+
+- class: [`Rector\DeadCode\Rector\ClassConst\RemoveUnusedClassConstantRector`](/../master/rules/dead-code/src/Rector/ClassConst/RemoveUnusedClassConstantRector.php)
+- [test fixtures](/../master/rules/dead-code/tests/Rector/ClassConst/RemoveUnusedClassConstantRector/Fixture)
+
+Remove unused class constants
+
+```diff
+ class SomeClass
+ {
+-    private const SOME_CONST = 'dead';
+-
+     public function run()
+     {
+     }
+ }
+```
+
+<br>
+
 ### `RemoveUnusedClassesRector`
 
 - class: [`Rector\DeadCode\Rector\Class_\RemoveUnusedClassesRector`](/../master/rules/dead-code/src/Rector/Class_/RemoveUnusedClassesRector.php)

rules/dead-code/src/Rector/ClassConst/RemoveUnusedClassConstantRector.php

@@ -0,0 +1,101 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\Rector\ClassConst;
+
+use PhpParser\Node;
+use PhpParser\Node\Stmt\ClassConst;
+use Rector\Core\Rector\AbstractRector;
+use Rector\Core\RectorDefinition\CodeSample;
+use Rector\Core\RectorDefinition\RectorDefinition;
+use Rector\NodeCollector\NodeFinder\ClassConstParsedNodesFinder;
+use Rector\NodeTypeResolver\Node\AttributeKey;
+
+/**
+ * @see \Rector\DeadCode\Tests\Rector\ClassConst\RemoveUnusedClassConstantRector\RemoveUnusedClassConstantRectorTest
+ */
+final class RemoveUnusedClassConstantRector extends AbstractRector
+{
+    /**
+     * @var ClassConstParsedNodesFinder
+     */
+    private $classConstParsedNodesFinder;
+
+    public function __construct(ClassConstParsedNodesFinder $classConstParsedNodesFinder)
+    {
+        $this->classConstParsedNodesFinder = $classConstParsedNodesFinder;
+    }
+
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Remove unused class constants', [
+            new CodeSample(
+                <<<'PHP'
+class SomeClass
+{
+    private const SOME_CONST = 'dead';
+
+    public function run()
+    {
+    }
+}
+PHP
+,
+                <<<'PHP'
+class SomeClass
+{
+    public function run()
+    {
+    }
+}
+PHP
+
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [ClassConst::class];
+    }
+
+    /**
+     * @param ClassConst $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if (count($node->consts) !== 1) {
+            return null;
+        }
+
+        /** @var string $class */
+        $class = $node->getAttribute(AttributeKey::CLASS_NAME);
+
+        // 0. constants declared in interfaces have to be public
+        if ($this->classLikeParsedNodesFinder->findInterface($class) !== null) {
+            $this->makePublic($node);
+            return $node;
+        }
+
+        /** @var string $constant */
+        $constant = $this->getName($node);
+
+        $directUseClasses = $this->classConstParsedNodesFinder->findDirectClassConstantFetches($class, $constant);
+        if ($directUseClasses !== []) {
+            return null;
+        }
+
+        $indirectUseClasses = $this->classConstParsedNodesFinder->findIndirectClassConstantFetches($class, $constant);
+        if ($indirectUseClasses !== []) {
+            return null;
+        }
+
+        $this->removeNode($node);
+
+        return null;
+    }
+}

rules/dead-code/tests/Rector/ClassConst/RemoveUnusedClassConstantRector/Fixture/external_public.php.inc

@@ -0,0 +1,20 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\ClassConst\RemoveUnusedClassConstantRector\Fixture;
+
+class ExternalPublic
+{
+    public const SOME_CONST = 'dead';
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\ClassConst\RemoveUnusedClassConstantRector\Fixture;
+
+class ExternalPublic
+{
+}
+
+?>

rules/dead-code/tests/Rector/ClassConst/RemoveUnusedClassConstantRector/Fixture/fixture.php.inc

@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\ClassConst\RemoveUnusedClassConstantRector\Fixture;
+
+class SomeClass
+{
+    private const SOME_CONST = 'dead';
+
+    public function run()
+    {
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\ClassConst\RemoveUnusedClassConstantRector\Fixture;
+
+class SomeClass
+{
+    public function run()
+    {
+    }
+}
+
+?>

rules/dead-code/tests/Rector/ClassConst/RemoveUnusedClassConstantRector/Fixture/skip_child_used.php.inc

@@ -0,0 +1,16 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\ClassConst\RemoveUnusedClassConstantRector\Fixture;
+
+class SkipChildUsed
+{
+    protected const SOME_CONST = 'dead';
+}
+
+class SomeChild extends SkipChildUsed
+{
+    public function run()
+    {
+        return self::SOME_CONST;
+    }
+}

rules/dead-code/tests/Rector/ClassConst/RemoveUnusedClassConstantRector/Fixture/skip_external_used.php.inc

@@ -0,0 +1,16 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\ClassConst\RemoveUnusedClassConstantRector\Fixture;
+
+class SkipExternalUsed
+{
+    public const SOME_CONST = 'dead';
+}
+
+class SomeUsed
+{
+    public function run()
+    {
+        return SkipExternalUsed::SOME_CONST;
+    }
+}

rules/dead-code/tests/Rector/ClassConst/RemoveUnusedClassConstantRector/Fixture/skip_multiple_constants.php.inc

@@ -0,0 +1,8 @@
+<?php
+
+namespace Rector\DeadCode\Tests\Rector\ClassConst\RemoveUnusedClassConstantRector\Fixture;
+
+class SkipMultipleConstants
+{
+    public const SOME_CONST = 'dead', NOT_USED_EITHER = 'dead';
+}

rules/dead-code/tests/Rector/ClassConst/RemoveUnusedClassConstantRector/RemoveUnusedClassConstantRectorTest.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DeadCode\Tests\Rector\ClassConst\RemoveUnusedClassConstantRector;
+
+use Iterator;
+use Rector\Core\Testing\PHPUnit\AbstractRectorTestCase;
+use Rector\DeadCode\Rector\ClassConst\RemoveUnusedClassConstantRector;
+
+final class RemoveUnusedClassConstantRectorTest 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 RemoveUnusedClassConstantRector::class;
+    }
+}

rules/solid/src/Rector/ClassConst/PrivatizeLocalClassConstantRector.php

@@ -188,7 +188,7 @@ PHP
         ?ConstantVisibility $constantVisibility,
         string $class
     ): void {
-        // 1. is actually never used (@todo use in "dead-code" set)
+        // 1. is actually never used
         if ($directUseClasses === []) {
             if ($indirectUseClasses !== [] && $constantVisibility !== null) {
                 $this->makePrivateOrWeaker($classConst, $constantVisibility);