xdebug-code-coverage (global)

xdebug-code-coverage.php

<?php
$_xdebug_code_coverage = new class {
    private $coverage;
    private $covFile;

    public function __construct()
    {
        require_once __DIR__ . '/../vendor/autoload.php';

        $uid = uniqid();
        $this->covFile = "/tmp/xdebug-code-coverage/${uid}.cov";

        $this->coverage = new \SebastianBergmann\CodeCoverage\CodeCoverage;
        $this->coverage->filter()->addDirectoryToWhitelist(__DIR__ . '/../app');
        $this->coverage->filter()->addDirectoryToWhitelist(__DIR__ . '/../batch');

        $this->coverage->start($uid);
    }

    public function __destruct()
    {
        $this->coverage->stop();
        (new \SebastianBergmann\CodeCoverage\Report\PHP)->process($this->coverage, $this->covFile);
    }
};

xdebug.ini:

[xdebug]
zend_extension = xdebug
xdebug.mode = coverage
auto_prepend_file = /var/www/tests/xdebug-coverage.php

to merge all data into one report:
./vendor/bin/phpcov merge --html ./coverage-report /tmp/xdebug-code-coverage/