PHPUnit_Framework_BaseTestListener class not found

Question

I am trying to run a PHPunit test for my extension but I keep getting the following error:
Fatal error: Class 'PHPUnit_Framework_BaseTestListener' not found in C:\xampp\htdocs\myDrupalsite\sites\all\modules\civicrm\Civi\Test\CiviTestListener.php on line 17
Any ideas on how I can fix this?
I am using CiviCRM 4.7
CMS is Drupal 7
My system OS is Windows 10. My extension is placed in <Drupal root>sites/default/files/civicrm/ext
My test directory was created using civix generate:test on the Windows command prompt.
I run the tests using PHPUnit via the command prompt in the root directory of my extension.

Answer 1

I run tests the following way

1. I test in a CiviCRM instance that is generated with buildkit (the toolchain provided for CiviCRM developers see https://docs.civicrm.org/dev/en/latest/tools/buildkit/ .
2. My tests are generated with civix generate:test. Remarks that this generator also creates the file tests/phpunit/bootstrap.php that takes care of the class loading.
3. I run the test from the extension directory by executing phpunit4 (This version is installed with buildkit).

Answer 2

This sounds like a mismatch in the phpunit versions:

• Currently, most of the Civi testing runs against the PHAR build of phpunit v4.
• phpunit v6 renames every class to use \ instead of _, which means that all the base-classes disappear if you run on a newer build of phpunit.