rector/rules/DeadCode/NodeFinder/NextVariableUsageNodeFinder.php

<?php

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

use PhpParser\Node;
use PhpParser\Node\Expr\Assign;
use PhpParser\Node\Expr\Variable;
use PhpParser\NodeTraverser;
use Rector\Core\PhpParser\Comparing\NodeComparator;
use Rector\Core\PhpParser\Node\BetterNodeFinder;
use Rector\NodeNameResolver\NodeNameResolver;
use Rector\NodeNestingScope\ParentScopeFinder;
use Rector\NodeTypeResolver\Node\AttributeKey;
use RectorPrefix20210713\Symplify\Astral\NodeTraverser\SimpleCallableNodeTraverser;
final class NextVariableUsageNodeFinder
{
    /**
     * @var \Rector\Core\PhpParser\Node\BetterNodeFinder
     */
    private $betterNodeFinder;
    /**
     * @var \Symplify\Astral\NodeTraverser\SimpleCallableNodeTraverser
     */
    private $simpleCallableNodeTraverser;
    /**
     * @var \Rector\NodeNameResolver\NodeNameResolver
     */
    private $nodeNameResolver;
    /**
     * @var \Rector\NodeNestingScope\ParentScopeFinder
     */
    private $parentScopeFinder;
    /**
     * @var \Rector\Core\PhpParser\Comparing\NodeComparator
     */
    private $nodeComparator;
    public function __construct(\Rector\Core\PhpParser\Node\BetterNodeFinder $betterNodeFinder, \RectorPrefix20210713\Symplify\Astral\NodeTraverser\SimpleCallableNodeTraverser $simpleCallableNodeTraverser, \Rector\NodeNameResolver\NodeNameResolver $nodeNameResolver, \Rector\NodeNestingScope\ParentScopeFinder $parentScopeFinder, \Rector\Core\PhpParser\Comparing\NodeComparator $nodeComparator)
    {
        $this->betterNodeFinder = $betterNodeFinder;
        $this->simpleCallableNodeTraverser = $simpleCallableNodeTraverser;
        $this->nodeNameResolver = $nodeNameResolver;
        $this->parentScopeFinder = $parentScopeFinder;
        $this->nodeComparator = $nodeComparator;
    }
    public function find(\PhpParser\Node\Expr\Assign $assign) : ?\PhpParser\Node
    {
        $scopeNode = $this->parentScopeFinder->find($assign);
        if ($scopeNode === null) {
            return null;
        }
        /** @var Variable $expr */
        $expr = $assign->var;
        $this->simpleCallableNodeTraverser->traverseNodesWithCallable((array) $scopeNode->stmts, function (\PhpParser\Node $currentNode) use($expr, &$nextUsageOfVariable) : ?int {
            // used above the assign
            if ($currentNode->getStartTokenPos() < $expr->getStartTokenPos()) {
                return null;
            }
            // skip self
            if ($this->nodeComparator->areSameNode($currentNode, $expr)) {
                return null;
            }
            if (!$this->nodeComparator->areNodesEqual($currentNode, $expr)) {
                return null;
            }
            $currentNodeParent = $currentNode->getAttribute(\Rector\NodeTypeResolver\Node\AttributeKey::PARENT_NODE);
            if ($currentNodeParent instanceof \PhpParser\Node\Expr\Assign && !$this->hasInParentExpression($currentNodeParent, $expr)) {
                return \PhpParser\NodeTraverser::STOP_TRAVERSAL;
            }
            $nextUsageOfVariable = $currentNode;
            return \PhpParser\NodeTraverser::STOP_TRAVERSAL;
        });
        return $nextUsageOfVariable;
    }
    private function hasInParentExpression(\PhpParser\Node\Expr\Assign $assign, \PhpParser\Node\Expr\Variable $variable) : bool
    {
        $name = $this->nodeNameResolver->getName($variable);
        if ($name === null) {
            return \false;
        }
        return $this->betterNodeFinder->hasVariableOfName($assign->expr, $name);
    }
}