Automated Testing in Django
- 1. How you can write awesome code if you have automated testing Loek van Gent Feb 3rd 2015
- 2. Loek van Gent #afk Hallo! Wa tokelwap! Tjike!
- 3. PHP (Zend)many, many years Django/Python 3 years
- 4. Who are you? Ah, this is about me too?
- 5. Yeah why? Why write tests?
- 6. ➔ Documentation? ➔ Cross-browser compatibility? ➔ Doing small tweaks? ➔ Getting all the pixels right? ➔ Writing tests? ➔ … Come on I'm a coder.... What’s the MOST fun in coding?
- 7. Exactly!!! Writing awesome code! What’s the MOST fun in coding?
- 8. What’s the LEAST fun in coding? ➔ Testing the entire project on every update? ➔ Fixing bugs? ➔ Crashing the live server? I can see where this is going...
- 9. Bugs? Bugs are nasty! Write tests!
- 10. 10
- 11. Automated tests Unit tests Individual methods Integration tests Grouped modules Functional tests Full stack / Front-end Some manual & user tests Acceptance test Accept new features, Go/No-Go to live Stress test Test server set-up (many requests) Usability test Test UX A/B testing Randomly present user option A or B. Test results. ...
- 12. Unit tests
- 13. Unit tests: An example How can this possibly go wrong? def early_bird_amount(amount): amount = 0.8 * amount return amount 100 → 80
- 14. Great update guys! def early_bird_amount(amount): -- amount = 0.8 * amount ++ amount = 0.6 * amount # Nice early bird deal return amount def early_bird_amount(amount): -- amount = 0.8 * amount ++ amount = 0.6 * amount # 60% of standard return amount 100 → 60 100 → 60
- 15. This should not go live. def early_bird_amount(amount): amount = 0.6 * amount # Nice early bird deal amount = 0.6 * amount # 60% of standard return amount OOPS! 100 → 36
- 16. We should have tested that! Ok, ok, I get it now.
- 17. Let's go! from .tickets import early_bird_amount from unittests import TestCase class TestAmounts(TestCase): def test_early_bird_amount(self): calculated_amount = early_bird_amount(100) self.assertEqual(calculated_amount, 60) Is it really THAT easy?!
- 18. Assert This is useful stuff! assertEqual assertNotEqual assertGreater assertIsNone assertIsInstance assertRaises ...
- 19. Unit test Test only one “unit”
- 20. User model: get_name() class User(models.Model): first_name = models.CharField(max_length=40) last_name = models.CharField(max_length=40) def get_name(self): return “ ”.join(self.first_name, self.last_name)
- 21. Let's test it. class TestCase(unittest.TestCase): def test_get_name(self): instance = User.objects.create( first_name="Django", last_name="Reinhardt") self.assertEqual(instance.get_name(), "Django Reinhardt") Done! This “unit” is tested, right?
- 22. Mock. Nice! I'm loving this Mock stuff already! class TestCase(unittest.TestCase): def test_get_name(self): mock_user = mock.Mock(spec=User) mock_user.first_name = "Django" mock_user.last_name = "Reinhardt" self.assertEqual(User.get_name(mock_user), "Django Reinhardt")
- 23. Functional tests
- 24. from django.test import LiveServerTestCase from selenium.webdriver.firefox.webdriver import WebDriver ➔ Runs server localhost ➔ Starts Firefox (headless) ➔ Find html elements ➔ Send clicks ➔ Fill forms ➔ Assert elements, url, text ➔ much more
- 25. <li id=”reinhardt”> <span class=”time”>16.15<span> <span class=”speaker”>Django Reinhardt</span> <em>Introduction to automated testing</em> </li> driver.get(“http://python-namibia.org/programme/”) presentation = driver.find_element_by_id('reinhardt') speaker = presentation.find_element_by_class('speaker') self.assertEqual(speaker.text, “Django Reinhardt”) presentation.assertTextPresent(“automated testing”)
- 26. Live demo!
- 28. Automated Cross-browser testing SauceLabs, BrowserStack, TestingBot
- 30. Continuous Integration Travis, Shippable, Jenkins
- 33. So, which test to use?
- 34. Well it's really up to you
- 35. Vital parts of your application ➔ payments ➔ permissions ➔ sensitive user data Unit or integration tests
- 36. Essential user flows ➔ sign up / log in ➔ all “happy” flows ➔ donations, project registration Functional tests
- 38. Workshop ➔ Django Testing Tutorial ➔ Bring you own project (Django?) and start writing tests. ➔ Write functional tests for a (live) website. ➔ Hookup Travis CI to you Github repo. ➔ Try out SauceLabs for manual cross browser testing. ➔ Anything...
- 39. Test Driven Development (TDD) ➔ Write tests for functionalities first, then code ➔ Write a test to catch a bug you find, then fix it.