https://knapsackpro.com/testing_frameworks/difference_between/behat/vs/simpletest
Behat vs SimpleTest comparison of testing frameworks
What are the differences between Behat and SimpleTest? Alternatives for testing frameworks in PHP.
testing frameworksbehatvssimpletestcomparison
https://api.drupal.org/api/drupal/modules%21simpletest%21simpletest.install/7.x
simpletest.install | Drupal API
simpletestinstalldrupalapi