Clock mocking¶

In order to solve all the time-related test errors, the PHPUnit bridge now includes a ClockMock class which can be used in your PHPUnit tests. This class replaces the PHP's built-in time(), microtime(), sleep() and usleep() functions by its own implementations.

This means that you don't need to make a single change in your original code, except when using time() to get the current time: the new DateTime() instruction must be replaced by DateTime::createFromFormat('U', time()).

The clock mocking is enabled on demand for the tests which need it. The recommended way to enable it is to add a special @group annotation:

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/**
 * @group time-sensitive
 */
class MyTest extends \PHPUnit_Framework_TestCase
{
    public function testSomething()
    {
        $stopwatch = new Stopwatch();

        $stopwatch->start();
        sleep(10);
        $duration = $stopwatch->stop();

        $this->assertEquals(10, $duration);
    }
}

And that's all! This test will never fail again because of getting a wrong time-related result. The sleep(10) call will make the clock advance 10 exact seconds and your test will always pass.

An added bonus of using the ClockMock class is that time passes instantly. Using PHP's sleep(10) will make your test wait for 10 actual seconds (more or less). In contrast, the ClockMock class advances the internal clock the given number of seconds without actually waiting that time, so your test will execute 10 seconds faster.

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<listeners>
    <listener class="Symfony\Bridge\PhpUnit\SymfonyTestsListener">
        <arguments>
            <array>
                <element><string>Symfony\Component\HttpFoundation</string></element>
            </array>
        </arguments>
    </listener>
</listeners>