Debug Memory Usage of PHPUnit TestCase

DebugMemoryUsageTestListener.php

<?php

declare(strict_types=1);

namespace App\Tests;

use PHPUnit\Framework\TestListener;
use PHPUnit\Framework\TestListenerDefaultImplementation;
use PHPUnit\Framework\TestSuite;

class DebugMemoryUsageTestListener implements TestListener
{
    use TestListenerDefaultImplementation;

    /**
     * The "endTestSuite" is called for every TestCase file, so we can make usage of that to clean up properties.
     */
    public function endTestSuite(TestSuite $suite): void
    {
        if (!\class_exists($suite->getName())) {
            return;
        }

        echo \PHP_EOL;
        echo $suite->getName();
        echo ' (' . $this->human_filesize(\memory_get_usage(true)) . ')';
    }

    public function human_filesize(int $bytes, int $dec = 2): string
    {
        $size = ['B', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
        $factor = \floor((\strlen((string) $bytes) - 1) / 3);
        if (0.0 === $factor) {
            $dec = 0;
        }

        return \sprintf("%.{$dec}f %s", $bytes / (1024 ** $factor), $size[$factor]);
    }
}

phpunit.xml.dist

<!-- add following to the phpunit.xml.dist -->

<listeners>
    <listener class="App\Tests\DebugMemoryUsageTestListener" />
</listeners>