requireExtends.duplicate

Code example

<?php declare(strict_types = 1);

/**
 * @phpstan-require-extends Base
 * @phpstan-require-extends AnotherBase
 */
interface Constrainable
{

}

Why is it reported?

The @phpstan-require-extends PHPDoc tag is used more than once on the same interface or trait. Since a class can only extend one parent class, there can only be one @phpstan-require-extends constraint. Having multiple tags is contradictory because a class cannot extend two different classes at the same time.

How to fix it

Keep only one @phpstan-require-extends tag:

 <?php declare(strict_types = 1);

 /**
  * @phpstan-require-extends Base
- * @phpstan-require-extends AnotherBase
  */
 interface Constrainable
 {

 }