CreateMockToAnonymousClassRector

Find another rule

Change $this->createMock() with methods to direct anonymous class

 use PHPUnit\Framework\TestCase;

 final class SomeTest extends TestCase
 {
     public function test()
     {
-        $someMockObject = $this->createMock(SomeClass::class);
-
-        $someMockObject->method('someMethod')
-            ->willReturn(100);
+        $someMockObject = new class extends SomeClass {
+            public function someMethod()
+            {
+                return 100;
+            }
+        };
     }
 }

Configure your rector.php:

<?php

use Rector\Config\RectorConfig;
use Rector\PHPUnit\CodeQuality\Rector\ClassMethod\CreateMockToAnonymousClassRector;

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