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
   

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2. Energy
   Pyramid
   

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3. Food
   Pyramid
   

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5. functional
   integration
   unit
   The testing
   pyramid
   

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6. Unit Tests
   test *1* thing in isolation
   

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7. SUPER
   FAST
   

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8. Integration Tests
   test things work together
   

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9. Functional Tests
   end-to-end testing
   

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10. Manual Testing
    people cycles not processor cycles
    

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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
    

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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
    

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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
    

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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
    And I press the verify button
    Then I should see the error message
    Examples:
    | invalid_number |
    | foo@example.com |
    | 0 |
    | +441411111111 |
    | +44712345678 |
    

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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
    And I press the verify button
    Then I should see the error message
    Examples:
    | invalid_number |
    | foo@example.com |
    | 0 |
    | +441411111111 |
    | +44712345678 |
    

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16. functional
    integration
    unit
    

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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()
    

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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()
    

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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()
    

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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()
    

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21. splinter &
    pytest-splinter
    

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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 ')
    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()
    

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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 ')
    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()
    

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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 ')
    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()
    

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27. @then('I should see the error message')
    def has_error_message(browser):
    browser.find_by_css('.message.error').first
    

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28. @then('I should see the error message')
    def has_error_message(browser):
    browser.find_by_css('.message.error').first
    

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29. @then('I should see the error message')
    def has_error_message(browser):
    browser.find_by_css('.message.error').first
    

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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()
    

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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()
    

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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()
    

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33. functional
    integration
    unit
    

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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...
    

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37. ryannevius.com
    

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38. functional
    integration
    unit
    

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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...
    

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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...
    

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41. mock.patch
    

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42. Connected
    

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44. Modular
    

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45. ⌥⌘M
    

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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...
    

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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...
    

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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...
    

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49. class NumberVerificationView(LoginRequiredMixin, FormView):
    ...
    def form_valid(self, form):
    # AND SO ON...
    return super(ContactView, self).form_valid(form)
    

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50. def validate_phone_number_characters(value):
    if re.search("[^0-9+-\\s]+", value):
    raise ValidationError(
    _('%(value) contains invalid characters'),
    params={'value': value},
    )
    

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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},
    )
    

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52. SUPER
    FAST
    

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53. property based testing
    http://hypothesis.works/
    

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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)
    

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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)
    

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58. httmock
    

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59. functional
    integration
    unit
    

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61. @pytest.mark.slowtest
    def test_function():
    pass
    

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62. @pytest.mark.slowtest
    def test_function():
    pass
    

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68. STOP!
    

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69. functional
    integration
    unit
    

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70. functional
    integration
    unit
    

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71. functional
    integration
    unit
    

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72. Grazie
    

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73. Django and the
    testing pyramid
    @aaronbassett
    

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