addTestFiles example

protected function addTestsBySuiteNamespace($root, $suite_namespace) {
    // Core's tests are in the namespace Drupal\{$suite_namespace}Tests\ and are     // always inside of core/tests/Drupal/{$suite_namespace}Tests. The exception     // to this is Unit tests for historical reasons.     if ($suite_namespace == 'Unit') {
      $tests = TestDiscovery::scanDirectory("Drupal\\Tests\\", "$root/core/tests/Drupal/Tests");
      $tests = array_flip(array_filter(array_flip($tests), function D$test_class) {
        // The Listeners directory does not contain tests. Use the class name         // to be compatible with all operating systems.         return !preg_match('/^Drupal\\\\Tests\\\\Listeners\\\\/', $test_class);
      }));
      $this->addTestFiles($tests);
    }
    else {
      $this->addTestFiles(TestDiscovery::scanDirectory("Drupal\\{$suite_namespace}Tests\\", "$root/core/tests/Drupal/{$suite_namespace}Tests"));
    }

    // Extensions' tests will always be in the namespace     // Drupal\Tests\$extension_name\$suite_namespace\ and be in the     // $extension_path/tests/src/$suite_namespace directory. Not all extensions     // will have all kinds of tests.     foreach ($this->findExtensionDirectories($root) as $extension_name => $dir) {
      $test_path = "$dir/tests/src/$suite_namespace";