rector/rules/DeadCode/Rector/Foreach_/RemoveUnusedForeachKeyRector.php

<?php

declare (strict_types=1);
namespace Rector\DeadCode\Rector\Foreach_;

use PhpParser\Node;
use PhpParser\Node\Stmt\Foreach_;
use Rector\Core\Rector\AbstractRector;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
/**
 * @see \Rector\Tests\DeadCode\Rector\Foreach_\RemoveUnusedForeachKeyRector\RemoveUnusedForeachKeyRectorTest
 */
final class RemoveUnusedForeachKeyRector extends \Rector\Core\Rector\AbstractRector
{
    public function getRuleDefinition() : \Symplify\RuleDocGenerator\ValueObject\RuleDefinition
    {
        return new \Symplify\RuleDocGenerator\ValueObject\RuleDefinition('Remove unused key in foreach', [new \Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample(<<<'CODE_SAMPLE'
$items = [];
foreach ($items as $key => $value) {
    $result = $value;
}
CODE_SAMPLE
, <<<'CODE_SAMPLE'
$items = [];
foreach ($items as $value) {
    $result = $value;
}
CODE_SAMPLE
)]);
    }
    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes() : array
    {
        return [\PhpParser\Node\Stmt\Foreach_::class];
    }
    /**
     * @param Foreach_ $node
     */
    public function refactor(\PhpParser\Node $node) : ?\PhpParser\Node
    {
        if ($node->keyVar === null) {
            return null;
        }
        $keyVar = $node->keyVar;
        $isNodeUsed = (bool) $this->betterNodeFinder->findFirst($node->stmts, function (\PhpParser\Node $node) use($keyVar) : bool {
            return $this->nodeComparator->areNodesEqual($node, $keyVar);
        });
        if ($isNodeUsed) {
            return null;
        }
        $node->keyVar = null;
        return $node;
    }
}