Dial T for Testing

A talk about testing and Django from the March 2014 DJUGL meetup.

Transcript

1. T testing for Dial
2. David Winterbottom @codeinthehole /codeinthehole
3. Tangent Labs @tangent_labs /tangentlabs
4. django-oscar @django_oscar /tangentlabs/django-oscar
6. Nose Nose nose.readthedocs.org
7. Django
8. Dexterity
9. Basics
10. Run ALL the tests
11. Run tests beneath path
12. Run test module
13. Run test class
14. Run test method
15. nosecomplete github.com/alonho/nosecomplete
16. nosecomplete github.com/alonho/nosecomplete
17. Stories
18. Stories Work on a feature
20. https://github.com/asdfasdf/spec Custom test runner
21. https://github.com/asdfasdf/spec Testing one module
22. https://github.com/asdfasdf/spec Spec plugin https://github.com/bitprophet/spec
23. https://github.com/asdfasdf/spec BDD-style output
24. class TestASignedInUser(WebTestCase):! ! def setUp(self):! self.user = G(User)! self.order = factories.create_order(user=self.user)! ! def test_can_see_their_email_address_on_the_profile_page(self):! profile_page = self.app.get(! reverse('customer:summary'), user=self.user)! self.assertTrue(self.email in profile_page.content)! ! def test_can_update_their_name(self):! profile_form_page = self.app.get(! reverse('customer:profile-update'), user=self.user)! form = profile_form_page.forms['profile_form']! form['first_name'] = 'Barry'! form['last_name'] = 'Chuckle'! response = form.submit()! self.assertRedirects(response, reverse('customer:summary'))! ! # Reload user! user = User.objects.get(id=self.user.id)! self.assertEquals("Barry", user.first_name)! self.assertEquals("Chuckle", user.last_name)!
25. class TestASignedInUser(WebTestCase):! ! def setUp(self):! self.user = G(User)! self.order = factoies.create_order(user=self.user)! ! def test_can_see_their_email_address_on_the_profile_page(self):! profile_page = self.app.get(! reverse('customer:summary'), user=self.user)! self.assertTrue(self.email in profile_page.content)! ! def test_can_update_their_name(self):! profile_form_page = self.app.get(! reverse('customer:profile-update'), user=self.user)! form = profile_form_page.forms['profile_form']! form['first_name'] = 'Barry'! form['last_name'] = 'Chuckle'! response = form.submit()! self.assertRedirects(response, reverse('customer:summary'))! ! # Reload user! user = User.objects.get(id=self.user.id)! self.assertEquals("Barry", user.first_name)! self.assertEquals("Chuckle", user.last_name)! System under test
26. class TestASignedInUser(WebTestCase):! ! def setUp(self):! self.user = G(User)! self.order = factories.create_order(user=self.user)! ! def test_can_see_their_email_address_on_the_profile_page(self):! profile_page = self.app.get(! reverse('customer:summary'), user=self.user)! self.assertTrue(self.email in profile_page.content)! ! def test_can_update_their_name(self):! profile_form_page = self.app.get(! reverse('customer:profile-update'), user=self.user)! form = profile_form_page.forms['profile_form']! form['first_name'] = 'Barry'! form['last_name'] = 'Chuckle'! response = form.submit()! self.assertRedirects(response, reverse('customer:summary'))! ! # Reload user! user = User.objects.get(id=self.user.id)! self.assertEquals("Barry", user.first_name)! self.assertEquals("Chuckle", user.last_name)! Specification
27. Use-cases Work on a new feature Refactor a feature
28. https://github.com/nose attribs/spec
29. nose.readthedocs.org/en/latest/plugins/attrib.html Run tagged tests
30. from nose.plugins.attrib import attr! ! ! @attr('shipping')! class TestFreeShippping(TestCase):! ! def test_is_free_for_empty_basket(self):! ...! ! ! class TestFixedPriceShipping(TestCase):! ! @attr(slow=True)! def test_returns_fixed_price_for_basket(self):! ...!
31. from nose.plugins.attrib import attr! ! ! @attr('shipping')! class TestFreeShippping(TestCase):! ! def test_is_free_for_empty_basket(self):! ...! ! ! class TestFixedPriceShipping(TestCase):! ! @attr(slow=True)! def test_returns_fixed_price_for_basket(self):! ...! Wrap a class
32. from nose.plugins.attrib import attr! ! ! @attr('shipping')! class TestFreeShippping(TestCase):! ! def test_is_free_for_empty_basket(self):! ...! ! ! class TestFixedPriceShipping(TestCase):! ! @attr(slow=True)! def test_returns_fixed_price_for_basket(self):! ...! Wrap a method
34. Pattern match tests github.com/iElectric/nose-selecttests
35. Use-cases Work on a new feature Refactor a feature Fix failing tests
36. Fail fast
37. Editor-friendly paths github.com/erikrose/nose-progressive
38. PDB on failure
39. Only re-run failed tests
40. Use-cases Work on a new feature Refactor a feature Fix failing tests Ready to push?
42. No plugins
43. Parallelise
44. Speed
45. 0 4 8 12 16 20 24 Focus / flow / “zone” Test suite time (seconds)
46. 0 4 8 12 16 20 24 Focus / flow / “zone” Test suite time (seconds) Pre-commit hook?
47. 0 4 8 12 16 20 24 Focus / flow / “zone” Test suite time (seconds)
48. 0 4 8 12 16 20 24 Test suite time (seconds)
51. Scam? blog.thecodewhisperer.com/2010/10/16/integrated-tests-are-a-scam/
52. import mock! from django.utils.functional import curry! ! no_database = curry(! mock.patch, 'django.db.backends.util.CursorWrapper',! Mock(side_effect=RuntimeError(! "Using the database is not permitted")))! ! ! @no_database()! class AUnitTest(TestCase):! ...! http://bit.ly/126vPrt
53. import mock! from django.utils.functional import curry! ! no_database = curry(! mock.patch, 'django.db.backends.util.CursorWrapper',! Mock(side_effect=RuntimeError(! "Using the database is not permitted")))! ! ! @no_database()! class AUnitTest(TestCase):! ...! http://bit.ly/126vPrt Currying mock.patch!
54. import mock! from django.utils.functional import curry! ! no_database = curry(! mock.patch, 'django.db.backends.util.CursorWrapper',! Mock(side_effect=RuntimeError(! "Using the database is not permitted")))! ! ! @no_database()! class AUnitTest(TestCase):! ...! http://bit.ly/126vPrt Wrap classes/methods
55. http://bit.ly/156c48x Number of tests Seconds
56. PASSWORD_HASHERS = ['django.contrib.auth.hashers.MD5PasswordHasher']
57. --processes=8
58. http://bit.ly/2gZnhj Boy scout rule...
59. Readability
60. http://bit.ly/19ganRJ (Refactoring a Test)
61. class TestBasket(TestCase):! ! def test_add_items(self):! # Create products! product_class = ProductClass(! name="Books", require_shipping=True)! product1 = Product.objects.create(title="My first book")! product2 = Product.objects.create(title="My second book")! partner = Partner.objects.create(name="Book Partner")! stockrecord1 = StockRecord(! price_excl_tax=D('12.00'), partner=partner)! stockrecord2 = StockRecord(! price_excl_tax=D('14.00'), partner=partner)! ! # Add to basket! basket = Basket()! basket.add(product1)! basket.add(product2)! ! total = basket.total_excl_tax! ! self.assertEqual(D('26.00'), total)! self.assertEqual(basket.num_lines, 2)! self.assertFalse(basket.is_empty)!
62. class TestBasket(TestCase):! ! def test_add_items(self):! # Create products! product_class = ProductClass(! name="Books", require_shipping=True)! product1 = Product.objects.create(title="My first book")! product2 = Product.objects.create(title="My second book")! partner = Partner.objects.create(name="Book Partner")! stockrecord1 = StockRecord(! price_excl_tax=D('12.00'), partner=partner)! stockrecord2 = StockRecord(! price_excl_tax=D('14.00'), partner=partner)! ! # Add to basket! basket = Basket()! basket.add(product1)! basket.add(product2)! ! total = basket.total_excl_tax! ! self.assertEqual(D('26.00'), total)! self.assertEqual(basket.num_lines, 2)! self.assertFalse(basket.is_empty)! Bad naming
63. class TestBasket(TestCase):! ! def test_add_items(self):! # Create products! product_class = ProductClass(! name="Books", require_shipping=True)! product1 = Product.objects.create(title="My first book")! product2 = Product.objects.create(title="My second book")! partner = Partner.objects.create(name="Book Partner")! stockrecord1 = StockRecord(! price_excl_tax=D('12.00'), partner=partner)! stockrecord2 = StockRecord(! price_excl_tax=D('14.00'), partner=partner)! ! # Add to basket! basket = Basket()! basket.add(product1)! basket.add(product2)! ! total = basket.total_excl_tax! ! self.assertEqual(D('26.00'), total)! self.assertEqual(basket.num_lines, 2)! self.assertFalse(basket.is_empty)! Heavy set-up
64. class TestBasket(TestCase):! ! def test_add_items(self):! # Create products! product_class = ProductClass(! name="Books", require_shipping=True)! product1 = Product.objects.create(title="My first book")! product2 = Product.objects.create(title="My second book")! partner = Partner.objects.create(name="Book Partner")! stockrecord1 = StockRecord(! price_excl_tax=D('12.00'), partner=partner)! stockrecord2 = StockRecord(! price_excl_tax=D('14.00'), partner=partner)! ! # Add to basket! basket = Basket()! basket.add(product1)! basket.add(product2)! ! total = basket.total_excl_tax! ! self.assertEqual(D('26.00'), total)! self.assertEqual(basket.num_lines, 2)! self.assertFalse(basket.is_empty)! Noise
65. class TestBasket(TestCase):! ! def test_add_items(self):! # Create products! product_class = ProductClass(! name="Books", require_shipping=True)! product1 = Product.objects.create(title="My first book")! product2 = Product.objects.create(title="My second book")! partner = Partner.objects.create(name="Book Partner")! stockrecord1 = StockRecord(! price_excl_tax=D('12.00'), partner=partner)! stockrecord2 = StockRecord(! price_excl_tax=D('14.00'), partner=partner)! ! # Add to basket! basket = Basket()! basket.add(product1)! basket.add(product2)! ! total = basket.total_excl_tax! ! self.assertEqual(D('26.00'), total)! self.assertEqual(basket.num_lines, 2)! self.assertFalse(basket.is_empty)! Unclear assertions
66. class TestBasket(TestCase):! ! def test_add_items(self):! # Create products! product_class = ProductClass(! name="Books", require_shipping=True)! product1 = Product.objects.create(title="My first book")! product2 = Product.objects.create(title="My second book")! partner = Partner.objects.create(name="Book Partner")! stockrecord1 = StockRecord(! price_excl_tax=D('12.00'), partner=partner)! stockrecord2 = StockRecord(! price_excl_tax=D('14.00'), partner=partner)! ! # Add to basket! basket = Basket()! basket.add(product1)! basket.add(product2)! ! total = basket.total_excl_tax! ! self.assertEqual(D('26.00'), total)! self.assertEqual(basket.num_lines, 2)! self.assertFalse(basket.is_empty)! Sloppy coding
67. class TestBasketTotal(TestCase):! ! def setUp(self):! self.basket = Basket()! ! def test_is_correct_after_adding_multiple_items(self):! products = [! factory.create_product(price_excl_tax=D('12.00')),! factory.create_product(price_excl_tax=D('14.00')),! ]! for product in products:! self.basket.add_product(product)! self.assertEqual(! D('12.00') + D('14.00'), self.basket.total_excl_tax)!
68. class TestBasketTotal(TestCase):! ! def setUp(self):! self.basket = Basket()! ! def test_is_correct_after_adding_multiple_items(self):! products = [! factory.create_product(price_excl_tax=D('12.00')),! factory.create_product(price_excl_tax=D('14.00')),! ]! for product in products:! self.basket.add_product(product)! self.assertEqual(! D('12.00') + D('14.00'), self.basket.total_excl_tax)! Descriptive names
69. class TestBasketTotal(TestCase):! ! def setUp(self):! self.basket = Basket()! ! def test_is_correct_after_adding_multiple_items(self):! products = [! factory.create_product(price_excl_tax=D('12.00')),! factory.create_product(price_excl_tax=D('14.00')),! ]! for product in products:! self.basket.add_product(product)! self.assertEqual(! D('12.00') + D('14.00'), self.basket.total_excl_tax)! Factory functions
70. class TestBasketTotal(TestCase):! ! def setUp(self):! self.basket = Basket()! ! def test_is_correct_after_adding_multiple_items(self):! products = [! factory.create_product(price_excl_tax=D('12.00')),! factory.create_product(price_excl_tax=D('14.00')),! ]! for product in products:! self.basket.add_product(product)! self.assertEqual(! D('12.00') + D('14.00'), self.basket.total_excl_tax)! Intention revealing
71. WebTest webtest.readthedocs.org/ def test_contact_us(self):! home = self.app.get('/')! ! # Fill in form! contact_us = home.click(linkid="contact_us_link")! form = contact_us.forms['profile_form']! form['name'] = 'Barry Chuckle'! form['query'] = 'To me?'! confirm = form.submit().follow()! ! self.assertTrue('Thanks Barry' in confirm.content)!
73. red green refactor
74. failing test passing test clean test fast test
75. no tests tests readable tests fast, readable tests
76. •Test suite is there to help you •Make it clear and easy to read •Make it fast •Master your test runner TLDR
77. •Write tests using the spec style •Use WebTest (not the Django client) Homework