RemoveUnusedClosureVariableUseRector.php

<?php

declare(strict_types=1);

namespace Rector\DeadCode\Rector\Concat;

use PhpParser\Node;
use PhpParser\Node\Expr\Closure;
use Rector\DeadCode\NodeAnalyzer\ExprUsedInNodeAnalyzer;
use Rector\PhpParser\Node\BetterNodeFinder;
use Rector\Rector\AbstractRector;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;

/**
 * @see \Rector\Tests\DeadCode\Rector\Closure\RemoveUnusedClosureVariableUseRector\RemoveUnusedClosureVariableUseRectorTest
 */
final class RemoveUnusedClosureVariableUseRector extends AbstractRector
{
    public function __construct(
        private readonly BetterNodeFinder $betterNodeFinder,
        private readonly ExprUsedInNodeAnalyzer $exprUsedInNodeAnalyzer
    ) {
    }

    public function getRuleDefinition(): RuleDefinition
    {
        return new RuleDefinition('Remove unused variable in use() of closure', [
            new CodeSample(
                <<<'CODE_SAMPLE'
$var = 1;

$closure = function() use ($var) {
    echo 'Hello World';
};

CODE_SAMPLE

                ,
                <<<'CODE_SAMPLE'
$var = 1;
$closure = function() {
    echo 'Hello World';
};

CODE_SAMPLE
            ),

        ]);
    }

    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes(): array
    {
        return [Closure::class];
    }

    /**
     * @param Closure $node
     */
    public function refactor(Node $node): ?Node
    {
        if ($node->uses === []) {
            return null;
        }

        $hasChanged = false;

        foreach ($node->uses as $key => $useVariable) {
            $useVariableName = $this->getName($useVariable->var);
            if (! is_string($useVariableName)) {
                continue;
            }

            $isUseUsed = (bool) $this->betterNodeFinder->findFirst(
                $node->stmts,
                fn (Node $subNode): bool => $this->exprUsedInNodeAnalyzer->isUsed($subNode, $useVariable->var)
            );
            if ($isUseUsed) {
                continue;
            }

            unset($node->uses[$key]);
            $hasChanged = true;

        }

        if ($hasChanged) {
            // reset keys, to keep as expected
            $node->uses = array_values($node->uses);
            return $node;
        }

        return null;
    }
}