Mocking final classes in phpUnit 9

This is a copy from Medium: https://medium.com/@gullevek/mocking-final-classes-in-phpunit-9-dee1944ca292

This is an add on to this wonderful article: https://tomasvotruba.com/blog/2019/03/28/how-to-mock-final-classes-in-phpunit/

It describes the basic flow, and also a way how to do this the current version of phpUnit (9.5.20 as of writing)

I want to add help to Point 4 Single Hook file setup.

It is a composer package, but that doesn’t matter for the phpUnit setup part

In my system the folder layout is as follows

• /phpunit.xml: config file for phpUnit
• /src: All the content for the composer package
• /vendor: the composer files
• /test: main test folder with info, etc files
• /test/phpUnit/: test files for phpUnit
• /test/phpUnit/Hook/: the folder with the phpUnit hooks.

TWO things I had to change to make this work

First: The hook has to be in the BeforeFirstTestHook and not BeforeTestHook or the test would run out of memory

<?php

// strip the final name from a to be mocked class

declare(strict_types=1);

namespace test\phpUnit\Hook;

use DG\BypassFinals;
use PHPUnit\Runner\BeforeFirstTestHook;

// only works if it is the FIRST load and not before EACH test
final class BypassFinalHook implements BeforeFirstTestHook
{
    public function executeBeforeFirstTest(): void
    {
        BypassFinals::enable();
    }
}

// __END__

Second: the phpunit.xml config file:

<phpunit>
     <!-- Below removes final from classes for mock tests -->
    <extensions>
        <extension class="test\phpUnit\Hook\BypassFinalHook" file="test/phpUnit/Hook/BypassFinalHook.php" />
    </extensions>
</phpunit>

With these two changes I could run this successfully and mock final classes in php and phpUnit 9