unit testing for Drupal

Feeling your hands getting sweaty every time you need to hit the deploy button? What if you ship compromised code to production and you break a few months' work? Who knows how many bugs will just start swarming around? Now, instead of having panic attacks over and over again, why don't you leverage automated testing in Drupal 8? “But how precisely can I implement it within Drupal core, within my custom Drupal website or my contributed project? What are my testing options at hand?” “What type of tests can I write and what automated...