phpunit.xml

<?xml version="1.0" encoding="utf-8"?>
<phpunit colors="true"
         bootstrap="vendor/autoload.php">
    <php>
        <ini name="error_reporting" value="E_ALL"/>
    </php>

    <testsuites>
        <testsuite name="Test Suite">
            <directory>./tests/</directory>
        </testsuite>
    </testsuites>

    <filter>
        <whitelist>
            <directory suffix=".php">./src</directory>
        </whitelist>
    </filter>
</phpunit>