Speeding up your tests, and also your code coverage!

bootstrap_test.php

<?php declare(strict_types=1);
require __DIR__ . '/../vendor/autoload.php';

if (extension_loaded('xdebug') &&
	version_compare('2.6.0', phpversion('xdebug'), '<=')) {
	xdebug_set_filter(
		XDEBUG_FILTER_CODE_COVERAGE,
		XDEBUG_PATH_WHITELIST,
		[dirname( __DIR__ ) . '/src']
	);
}

// more

build-snippet.xml

<target name="phpunit-ci" description="Run unit tests with PHPUnit (full XDebug coverage)">
    <exec executable="/usr/bin/php" failonerror="false">
        <arg line=" -d zend_extension=xdebug.so -dxdebug.remote_enable=on vendor/bin/phpunit"/>
        <arg line="--configuration=${basedir}/phpunit.xml.dist"/>
        <arg line="--coverage-html=${basedir}/build/artifacts/coverage"/>
        <arg line="--coverage-xml=${basedir}/build/artifacts/coverage/xml"/>
        <arg line="--log-junit=${basedir}/build/artifacts/logs/junit.xml"/>
        <arg line="--coverage-clover=${basedir}/build/artifacts/logs/clover.xml"/>
    </exec>
</target>

phpunit-snippet.xml.dist

<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/7.2/phpunit.xsd"
    bootstrap = "app/bootstrap_test.php"
    ... other configs
>