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:

 <?php
 
 use PHPUnit\Framework\TestCase;

         $this->createMock('SomeClass')
             ->expects($this->once())
             ->method('someMethod')
-            ->with($this->callback(static function (array $args): bool {
-               return count($args) === 2 && $args[0] === 'correct';
+            ->with($this->callback(static function (array $args): bool {
+                $this->assertCount(2, $args);
+                $this->assertSame('correct', $args[0]);
+                return true;
             }));
     }
 }

PHP snippet to change

<?php

use PHPUnit\Framework\TestCase;

final class SomeTest extends TestCase
{
    public function test()
    {
        $this->createMock('SomeClass')
            ->expects($this->once())
            ->method('someMethod')
            ->with($this->callback(static function (array $args): bool {
               return count($args) === 2 && $args[0] === 'correct';
            }));
    }
}

Applied Rules:

WithCallbackIdenticalToStandaloneAssertsRector

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\PHPUnit\CodeQuality\Rector\MethodCall\WithCallbackIdenticalToStandaloneAssertsRector;

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

Rector version: 0594c1 - released at 2026-05-08 19:57