trying to delete a line with a custom rector rule #9085

prescriptionlifeline · 2025-04-01T13:46:15Z

prescriptionlifeline
Apr 1, 2025

Here's my Rector rule / rector.php (to make for an easier demo I've just put the Rector rule in rector.php):

<?php
use Rector\Config\RectorConfig;

use PhpParser\Node;
use PhpParser\Node\Expr\New_;
use PhpParser\NodeTraverser;
use PHPStan\Type\ObjectType;
use Rector\Contract\Rector\RectorInterface;
use Rector\Rector\AbstractRector;

class TestRector extends AbstractRector implements RectorInterface
{
    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes() : array
    {
        return [New_::class];
    }
    /**
     * @param New_ $node
     */
    public function refactor(Node $node) : ?int
    {
        if ($this->isObjectType($node->class, new ObjectType('A'))) {
            return NodeTraverser::REMOVE_NODE;
        }
        return null;
    }
}

return RectorConfig::configure()
    ->withRules([
        TestRector::class,
    ]);

I'm doing return NodeTraverser::REMOVE_NODE; to remove the node because that's what https://getrector.com/blog/5-tricks-to-write-better-custom-rules#content-4-return-nodetraverserremovenode-to-remove-the-stmt-node says to do.

I have one file in src/ - src/test.php:

<?php
class A {}
$a = new A();
echo 'all done!';

When I run my Rector rule I get this:

c:\games\rector2\

c:\phptst\rector

 1/1 [============================] 100%

                                       ector\src\test.php" file, due to:
                                     returned invalid value of type integer"
         Run Rector with "--debug" option and post the report here: https://github.com/rectorphp/rector/issues/new". On line: 146

The fact that the debug text is being cut off is most unhelpful. I I shrink the Windows 11 PowerShell window down as much as I can and then rerun Rector I get this:

 1/1 [============================] 100%
 [ERROR] Could not process
         "C:\phptst\rector\src\test.php"
                    o:
         "System error: "leaveNode()
         returned invalid value of type

         Run Rector with "--debug" option
         and post the report here: https://github.com/rectorphp/rector/issues/new". On
         line: 146

So I guess the return NodeTraverser::REMOVE_NODE; that https://getrector.com/blog/5-tricks-to-write-better-custom-rules#content-4-return-nodetraverserremovenode-to-remove-the-stmt-node is suggesting be done is incorrect? If so what would be the best way to remove the node in this case?

RemoveDeadReturnRector does unset($node->stmts[$lastStmtKey]); but because the node I'm trying to remove doesn't have any statements nested within it that wouldn't work.

And, for what it's worth, I'm aware that this Rector rule, by itself, would result in a src/test.php that doesn't run, but that doesn't change the fact that https://getrector.com/blog/5-tricks-to-write-better-custom-rules#content-4-return-nodetraverserremovenode-to-remove-the-stmt-node implies that the rector rule should remove that line when, in fact, it doesn't.

Any ideas?