For XenForo v2.1 addons, you should use Unit Test Framework v1.x
For XenForo v2.2 addons, you should use Unit Test Framework v2.x
Upgrading
v2.1
The TestCase.php and CreatesApplication.php files have been updated in v2.1 and you should edit these files in your addon unit test directory to merge in these changes.
Specifically, there is a new variable in TestCase.php:
PHP:
protected $addonsToLoad = [];
... and some new code in CreatesApplication.php which should be...