Try Rector Online | Rector - Automated Way to Instantly Upgrade and Refactor any PHP code

Run Rector on your code to see what it can do for you:

 	public function sayHello(string $command): void
 	{
 		$existingTags = shell_exec($command);
-		if (!$existingTags) {
+		if ($existingTags === '' || $existingTags === '0' || $existingTags === false || $existingTags === null) {
 		}
 	}
 }

PHP snippet to change

<?php declare(strict_types = 1);

class HelloWorld
{
	public function sayHello(string $command): void
	{
		$existingTags = shell_exec($command);
		if (!$existingTags) {
		}
	}
}

Applied Rules:

BooleanInBooleanNotRuleFixerRector

Not a change you expect?

Create an issue on GitHub
...or to speed up fix – add a test fixture

Config rector.php

<?php

use Rector\Config\RectorConfig;
use Rector\Strict\Rector\BooleanNot\BooleanInBooleanNotRuleFixerRector;

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

Rector version: 302c5e - released at 2025-04-18 18:21