coverage.xml

<?xml version="1.0" encoding="utf-8"?>
<phpunit bootstrap="classes/required_classes.php">
    <testsuites>
        <testsuite name="coverage">
            <directory>tests/unit</directory>
        </testsuite>
    </testsuites>
    <filter>
        <whitelist addUncoveredFilesFromWhitelist="true">
            <directory suffix=".php">classes</directory>
            <file>index.php</file>
        </whitelist>
    </filter>
    <logging>
        <log type="coverage-html" target="./tests/coverage" charset="UTF-8"
             highlight="false" lowUpperBound="35" highLowerBound="70"/>
    </logging>
</phpunit>