PHPUnit config: make sure unexpected output fails the tests

Author: jrfnl

phpunit.xml.dist

@@ -3,6 +3,7 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.2/phpunit.xsd"
     backupGlobals="true"
+    beStrictAboutOutputDuringTests="true"
     beStrictAboutTestsThatDoNotTestAnything="false"
     bootstrap="tests/bootstrap.php"
     convertErrorsToExceptions="true"