Django and the testing pyramid - DjangoCon Europe 2017

Video: https://www.youtube.com/watch?v=Mb4P0vnmymM

Model mommy lettuce factory boy expects gherkin behave. Travis mock splinter nose phantom hypothesis!

Most developers recognise the importance of testing in building maintainable software, but the sheer volume of tools and approaches can be bewildering and sometimes make it sound like you’re talking a different language.

In this talk we’ll look at the testing pyramid. We’ll discuss how approaching our testing in layers can increase developer productivity by reducing the time taken to run our test suites. We’ll look at the importance of different testing types including integration and acceptance testing. Finally we’ll introduce some tools and packages you can use to make writing good tests easier.

By the end you'll be able to talk TDD and BDD like a native!

Transcript

1. Django and the testing pyramid @aaronbassett
2. Energy Pyramid
3. Food Pyramid
5. functional integration unit The testing pyramid
6. Unit Tests test *1* thing in isolation
7. SUPER FAST
8. Integration Tests test things work together
9. Functional Tests end-to-end testing
10. Manual Testing people cycles not processor cycles
11. Feature: Number verification Users can add verified mobile numbers to their profile Scenario: Adding a valid phone number Given I'm an authenticated user And I have a valid phone number When I go to the phone number page And I press the verify button Then I should not see the error message
12. Feature: Number verification Users can add verified mobile numbers to their profile Scenario: Adding a valid phone number Given I'm an authenticated user And I have a valid phone number When I go to the phone number page And I press the verify button Then I should not see the error message
13. Feature: Number verification Users can add verified mobile numbers to their profile Scenario: User enters an invalid phone number Given I'm an authenticated user When I go to the phone number page And I enter ‘not a number’ And I press the verify button Then I should see the error message
14. Feature: Number verification Users can add verified mobile numbers to their profile Scenario: User enters an invalid phone number Given I'm an authenticated user When I go to the phone number page And I enter <invalid_number> And I press the verify button Then I should see the error message Examples: | invalid_number | | foo@example.com | | 0 | | +441411111111 | | +44712345678 |
15. Feature: Number verification Users can add verified mobile numbers to their profile Scenario: User enters an invalid phone number Given I'm an authenticated user When I go to the phone number page And I enter <invalid_number> And I press the verify button Then I should see the error message Examples: | invalid_number | | foo@example.com | | 0 | | +441411111111 | | +44712345678 |
16. functional integration unit
17. @given("I'm an authenticated user") def authenticat_user(browser): browser.visit(urljoin(browser.url, '/login/') browser.fill('username', 'test_user') browser.fill('password', 'test_password') button = browser.find_by_css('button[name=submit]').first.click()
18. @given("I'm an authenticated user") def authenticat_user(browser): browser.visit(urljoin(browser.url, '/login/') browser.fill('username', 'test_user') browser.fill('password', 'test_password') button = browser.find_by_css('button[name=submit]').first.click()
19. @given("I'm an authenticated user") def authenticat_user(browser): browser.visit(urljoin(browser.url, '/login/') browser.fill('username', 'test_user') browser.fill('password', 'test_password') button = browser.find_by_css('button[name=submit]').first.click()
20. @given("I'm an authenticated user") def authenticat_user(browser): browser.visit(urljoin(browser.url, '/login/') browser.fill('username', 'test_user') browser.fill('password', 'test_password') button = browser.find_by_css('button[name=submit]').first.click()
21. splinter & pytest-splinter
24. @when('I go to the phone number page') def go_to_number_submission_page(browser): browser.visit(urljoin(browser.url, '/number/') @when('I enter <invalid_number>') def enter_invalid_number(browser, invalid_number): browser.fill('number', invalid_number) @when('I press the verify button') def submit_number(browser): browser.find_by_css('button[name=verify]').first.click()
25. @when('I go to the phone number page') def go_to_number_submission_page(browser): browser.visit(urljoin(browser.url, '/number/') @when('I enter <invalid_number>') def enter_invalid_number(browser, invalid_number): browser.fill('number', invalid_number) @when('I press the verify button') def submit_number(browser): browser.find_by_css('button[name=verify]').first.click()
26. @when('I go to the phone number page') def go_to_number_submission_page(browser): browser.visit(urljoin(browser.url, '/number/') @when('I enter <invalid_number>') def enter_invalid_number(browser, invalid_number): browser.fill('number', invalid_number) @when('I press the verify button') def submit_number(browser): browser.find_by_css('button[name=verify]').first.click()
27. @then('I should see the error message') def has_error_message(browser): browser.find_by_css('.message.error').first
28. @then('I should see the error message') def has_error_message(browser): browser.find_by_css('.message.error').first
29. @then('I should see the error message') def has_error_message(browser): browser.find_by_css('.message.error').first
30. @given("I'm an authenticated user") def authenticat_user(browser): browser.visit(urljoin(browser.url, '/login/') browser.fill('username', 'test_user') browser.fill('password', 'test_password') button = browser.find_by_css('button[name=submit]').first.click()
31. @given('I\'m logged in') @given("I'm an authenticated user") @given('I log in') def authenticat_user(browser): browser.visit(urljoin(browser.url, '/login/') browser.fill('username', 'test_user') browser.fill('password', 'test_password') button = browser.find_by_css('button[name=submit]').first.click()
32. @given('I\'m logged in') @given("I'm an authenticated user") @given('I log in') def authenticat_user(browser): browser.visit(urljoin(browser.url, '/login/') browser.fill('username', 'test_user') browser.fill('password', 'test_password') button = browser.find_by_css('button[name=submit]').first.click()
33. functional integration unit
34. def start_number_verification(request): if request.method == "POST": if request.user.is_authenticated: number = request.POST.get("number", None) if re.search("[^0-9+-\\s]+", number): raise Exception existing_validation_requests = ValidationRequest.objects.filter( number=number, active=True ) if existing_validation_requests.exists(): raise Exception # AND SO ON...
37. ryannevius.com
38. functional integration unit
39. def start_number_verification(request): if request.method == "POST": if request.user.is_authenticated: number = request.POST.get("number", None) if re.search("[^0-9+-\\s]+", number): raise Exception existing_validation_requests = ValidationRequest.objects.filter( number=number, active=True ) if existing_validation_requests.exists(): raise Exception # AND SO ON...
40. def start_number_verification(request): if request.method == "POST": if request.user.is_authenticated: number = request.POST.get("number", None) if re.search("[^0-9+-\\s]+", number): raise Exception existing_validation_requests = ValidationRequest.objects.filter( number=number, active=True ) if existing_validation_requests.exists(): raise Exception # AND SO ON...
41. mock.patch
42. Connected
44. Modular
45. ⌥⌘M
46. class NumberVerificationView(View): def start_number_verification(request): if request.user.is_authenticated: number = request.POST.get("number", None) if re.search("[^0-9+-\\s]+", number): raise Exception existing_validation_requests = ValidationRequest.objects.filter( number=number, active=True ) if existing_validation_requests.exists(): raise Exception # AND SO ON...
47. class NumberVerificationView(LoginRequiredMixin, View): login_url = '/login/' redirect_field_name = 'redirect_to' def start_number_verification(request): number = request.POST.get("number", None) if re.search("[^0-9+-\\s]+", number): raise Exception existing_validation_requests = ValidationRequest.objects.filter( number=number, active=True ) if existing_validation_requests.exists(): raise Exception # AND SO ON...
48. class NumberVerificationView(LoginRequiredMixin, FormView): ... def form_valid(self, form): number = request.POST.get("number", None) if re.search("[^0-9+-\\s]+", number): raise Exception existing_validation_requests = ValidationRequest.objects.filter( number=number, active=True ) if existing_validation_requests.exists(): raise Exception # AND SO ON...
49. class NumberVerificationView(LoginRequiredMixin, FormView): ... def form_valid(self, form): # AND SO ON... return super(ContactView, self).form_valid(form)
50. def validate_phone_number_characters(value): if re.search("[^0-9+-\\s]+", value): raise ValidationError( _('%(value) contains invalid characters'), params={'value': value}, )
51. def validate_no_active_verification_requests(value): existing_validation_requests = ValidationRequest.objects.filter( number=value, active=True ) if existing_validation_requests.exists(): raise ValidationError( _('There is already a pending request for %(value)'), params={'value': value}, )
52. SUPER FAST
53. property based testing http://hypothesis.works/
54. @given(invalid_phone_number) @settings(max_examples=1000) def test_names_match_our_requirements(number): with pytest.raises(ValidationError, message="Expecting ValidationError"): validate_phone_number_characters(number)
55. @given(invalid_phone_number) @settings(max_examples=1000) def test_names_match_our_requirements(number): with pytest.raises(ValidationError, message="Expecting ValidationError"): validate_phone_number_characters(number)
58. httmock
59. functional integration unit
61. @pytest.mark.slowtest def test_function(): pass
62. @pytest.mark.slowtest def test_function(): pass
68. STOP!
69. functional integration unit
70. functional integration unit
71. functional integration unit
72. Grazie
73. Django and the testing pyramid @aaronbassett