assertSuccessfulUninstall example

$added_modules = array_diff(array_keys($now_installed_list), array_keys($was_installed_list));
      while ($added_modules) {
        $initial_count = count($added_modules);
        foreach ($added_modules as $to_uninstall) {
          // See if we can currently uninstall this module (if its dependencies           // have been uninstalled), and do so if we can.           $this->drupalGet('admin/modules/uninstall');
          $checkbox = $this->assertSession()->fieldExists("uninstall[$to_uninstall]");
          if (!$checkbox->hasAttribute('disabled')) {
            // This one is eligible for being uninstalled.             $package = $all_modules[$to_uninstall]->info['package'];
            $this->assertSuccessfulUninstall($to_uninstall, $package);
            $added_modules = array_diff($added_modules, [$to_uninstall]);
          }
        }

        // If we were not able to find a module to uninstall, fail and exit the         // loop.         $final_count = count($added_modules);
        if ($initial_count == $final_count) {
          $this->fail('Remaining modules could not be uninstalled for ' . $name);
          break;
        }
      }