Exemplo phpunit.xml com coverage.

phpunit.xml

<phpunit colors="true" bootstrap="vendor/autoload.php">
    <testsuites>
        <testsuite name="Tdd">
            <directory suffix=".php">tests/</directory>
        </testsuite>
    </testsuites>

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

    <logging>
        <log
                type="coverage-html"
                target="data/coverage"
                charset="UTF-8"
                yui="true"
                highlight="true"
                lowUpperBound="35"
                highUpperBound="70"/>
    </logging>
</phpunit>