Simplest PhpUnit extension reporting slow tests

SpeedTrapListener.php

<?php

declare(strict_types=1);

namespace Test\SpeedTrapListener;

use PHPUnit\Runner\AfterLastTestHook;
use PHPUnit\Runner\AfterTestHook;
use PHPUnit\Runner\BeforeTestHook;

final class SpeedTrapListener implements BeforeTestHook, AfterTestHook, AfterLastTestHook {

    private float $timeLimit;
    private float $startedAt;
    private array $slowTests = [];

    public function __construct(float $timeLimit = 500.0)
    {
        $this->timeLimit = $timeLimit;
    }

    public function executeBeforeTest(string $test): void
    {
        $this->startedAt = microtime(true);
    }

    public function executeAfterTest(string $test, float $time): void
    {
        $current = microtime(true);
        $elapsed = ($current * 1000) - ($this->startedAt * 1000);

        if ($elapsed > $this->timeLimit) {
            $this->slowTests[$test] = $elapsed;
        }
    }

    public function executeAfterLastTest(): void
    {
        if (empty($this->slowTests)) {
            return;
        }

        asort($this->slowTests);
        $this->slowTests = array_reverse($this->slowTests);

        echo PHP_EOL, PHP_EOL;
        echo 'Slow tests detected:', PHP_EOL;
        foreach ($this->slowTests as $testName => $elapsed) {
           printf('  (%6dms) %s%s', $elapsed, $testName, PHP_EOL);
        }
    }
}