vendor/bin/phpunit
<filter>
, нужно написать что-то другое.<?xml version="1.0" encoding="utf-8"?>
<phpunit bootstrap="./vendor/autoload.php"
colors="true"
convertErrorsToExceptions="true"
convertNoticesToExceptions="true"
convertWarningsToExceptions="true"
stopOnFailure="false">
<testsuites>
<testsuite name="Test Suite">
<directory>./tests</directory>
</testsuite>
</testsuites>
<filter>
<whitelist>
<directory suffix=".php">./src/</directory>
</whitelist>
</filter>
</phpunit>