Is TDD dead? A cheeky guide to PhpSpec

A look at PhpSpec and why it could be an alternative to PHP Unit.

Transcript

1. Is TDD dead? a cheeky guide to phpspec 12 August 2015
2. Marek Matulka Software Engineer SensioLabs UK @super_marek
4. no tests
6. my first unit tests
8. discovering BDD
10. Write a failing scenario (feature)
11. Write a failing scenario (feature) Write a failing test
12. Write a failing scenario (feature) Write a failing test Make your test pass
13. Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code
14. Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Repeat the fail-pass-refactor cycle as necessary
15. Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Make your feature pass
16. Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Make your feature pass BDD TDD
17. Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Make your feature pass BDD TDD External Quality Internal Quality
19. Existing project $ composer require --dev phpspec/phpspec
20. Starting new project? { "require-dev": { "phpspec/phpspec": "~2.0" }, "config": { "bin-dir": "bin" }, "autoload": {"psr-0": {"": "src"}} }
21. first spec $ bin/phpspec desc Acme\\StringCalculator
22. first spec $ bin/phpspec desc Acme\\StringCalculator Specification for Acme\StringCalculator created in /home/marek/Workspace/phpsw/spec/Acme/StringCalculatorSpec.php. $
23. first spec $ bin/phpspec desc Acme\\StringCalculator Specification for Acme\StringCalculator created in /home/marek/Workspace/phpsw/spec/Acme/StringCalculatorSpec.php. $ bin/phpspec run
24. first spec $ bin/phpspec run Acme/StringCalculator 10 - it is initializable class Acme\StringCalculator does not exist. Do you want me to create `Acme\StringCalculator` for you? [Y/n]
25. first spec Do you want me to create `Acme\StringCalculator` for you? [Y/n] Class Acme\StringCalculator created in /home/marek/Workspace/phpsw/src/Acme/StringCalculator.php. 1 specs 1 example (1 passed) 9ms $
26. spec/Acme/StringCalculatorSpec.php <?php namespace spec\Acme; use PhpSpec\ObjectBehavior; use Prophecy\Argument; class StringCalculatorSpec extends ObjectBehavior { function it_is_initializable() { $this->shouldHaveType('Acme\StringCalculator'); } }
27. src/Acme/StringCalculator.php <?php namespace Acme; class StringCalculator { }
29. spec/Acme/StringCalculatorSpec.php class StringCalculatorSpec extends ObjectBehavior { function it_is_initializable() { $this->shouldHaveType('Acme\StringCalculator'); } function it_calculates_empty_string_and_returns_zero() { $this->calculate('')->shouldReturn(0); } }
30. $ bin/phpspec run Do you want me to create `Acme\StringCalculator::calculate()` for you? [Y/n] Method Acme\StringCalculator::calculate() has been created. $
31. $ bin/phpspec run --fake Do you want me to create `Acme\StringCalculator::calculate()` for you? [Y/n] Method Acme\StringCalculator::calculate() has been created. Do you want me to make `Acme\StringCalculator::calculate()` always return 0 for you? [Y/n] Method Acme\StringCalculator::calculate() has been modified. $
32. $ bin/phpspec run --format pretty Acme\StringCalculator 10 ✔ is initializable 15 ✔ calculates empty string and returns zero 1 specs 2 examples (2 passed) 6ms $ bin/phpspec run -fpretty
33. src/Acme/StringCalculator.php <?php namespace Acme; class StringCalculator { public function calculate($argument1) { return 0; } }
34. $ bin/phpspec run --format pretty Acme\StringCalculator 10 ✔ is initializable 15 ✔ calculates empty string and returns zero 20 ✔ adds two plus separated integers 25 ✔ adds many plus separated integers 1 specs 4 examples (4 passed) 8ms $ TDD
35. class StringCalculator { /** * @param string $input * * @return integer */ public function calculate($input) { $parts = explode('+', $input); array_walk($parts, function (&$item) { return trim($item); }); return array_sum($parts); } }
36. stub
37. namespace Acme; interface LearnerRepository { /** * @param integer $id * * @return Learner */ public function findLearnerById($id); }
38. use Acme\LearnerRepository; class LearnerDetailsControllerSpec extends ObjectBehaviour { function it_loads_learner(LearnerRepository $repository) { $learner = new Learner(); $repository->findLearnerById(5)->willReturn($learner); $this->learnerDetailsAction(5)->shouldReturn($learner); } }
39. mock
40. namespace Acme; interface MessageDispatcher { /** * @param integer $id * * @return Message */ public function dispatch(Message $message); }
41. use Acme\LearnerRepository; use Acme\MessageDispatcher; class LearnerDetailsControllerSpec extends ObjectBehaviour { function it_loads_learner(LearnerRepository $repository, MessageDispatcher $dispatcher ) { $learner = new Learner(); $repository->findLearnerById(5)->willReturn($learner); $dispatcher->dispatch(Argument::type(Message::class) ->shouldBeCalled(); $this->learnerDetailsAction(5)->shouldReturn($learner); } }
42. spy
43. use Acme\LearnerRepository; use Acme\MessageDispatcher; class LearnerDetailsControllerSpec extends ObjectBehaviour { function it_loads_learner(LearnerRepository $repository, MessageDispatcher $dispatcher ) { $learner = new Learner(); $repository->findLearnerById(5)->willReturn($learner); $this->learnerDetailsAction(5)->shouldReturn($learner); $dispatcher->dispatch(Argument::type(Message::class) ->shouldHaveBeenCalled(); } }
44. constructing objects
45. use Acme\LearnerRepository; use Acme\MessageDispatcher; class LearnerDetailsControllerSpec extends ObjectBehaviour { function let( LearnerRepository $repository, MessageDispatcher $dispatcher ) { $this->beConstractedWith($repository, $dispatcher); } function it_loads_learner(LearnerRepository $repository, MessageDispatcher $dispatcher ) { // test... }
46. class LearnerSpec extends ObjectBehaviour { function let() { $this->beConstractedThrough( 'fromEmail', ['user@example.com'] ); } }
47. class LearnerSpec extends ObjectBehaviour { function let() { $this->beConstractedThrough( 'fromEmail', ['user@example.com'] ); } function it_can_be_created_with_name() { $this->beConstractedThrough('fromName', ['Test User']); $this->getEmail()->shouldBe(NULL); $this->getName()->shouldReturn('Test User'); }
48. matchers
49. Identity Matcher class TrainingAdministratorSpec extends ObjectBehavior { function let() { $this->beConstructedWith("Test User", "ROLE_COORDINATOR"); } function it_is_a_training_coordinator() { $this->isManager()->shouldBe(false); $this->isCoordinator()->shouldBe(true); $this->getRole()->shouldReturn("ROLE_COORDINATOR"); $this->getName()->shouldBeEqualTo("Test User"); }
50. Throw Matcher class TrainingAdministratorSpec extends ObjectBehavior { function it_should_not_allow_empty_name() { $this->shouldThrow('\InvalidArgumentException') ->during('changeName', ['']); } function it_should_not_allow_empty_name() { $this->shouldThrow(new \InvalidArgumentException()) ->duringChangeName(''); } }
51. Throw Matcher class TrainingAdministratorSpec extends ObjectBehavior { function it_should_not_allow_empty_name() { $this->beConstructedWith(''); $this->shouldThrow('\InvalidArgumentException') ->duringInstantiation(); } }
52. Type Matcher class TrainingAdministratorSpec extends ObjectBehavior { function it_should_be_a_training_administrator() { $this->shouldHaveType(TrainingAdministrator::class); $this->shouldReturnAnInstanceOf(TrainingAdministrator::class); $this->shouldBeAnInstanceOf(TrainingAdministrator::class); $this->shouldImplement(TrainingAdministrator::class); } }
53. Object State Matcher class TrainingAdministratorSpec extends ObjectBehavior { function it_should_be_a_training_administrator() { $this->isManager()->shouldBe(false); $this->isCoordinator()->shouldBe(true); // calls TrainingAdministrator::isCoordinator() $this->shoudBeCoordinator(); // calls TrainingAdministrator::hasRole() $this->shouldHaveRole('ROLE_COORDINATOR'); } }
54. Count Matcher class TrainingAdministratorSpec extends ObjectBehavior { function it_should_have_one_role() { $this->getRoles()->shouldHaveCount(1); } }
55. String Matcher class TrainingAdministratorSpec extends ObjectBehavior { function it_should_have_a_string_as_name() { $this->beConstructedWith('Test User'); $this->getName()->shouldBeString(); $this->getName()->shouldStartWith('Test'); $this->getName()->shouldEndWith('User'); $this->getName()->shouldMatch('/test/i'); } }
56. Array Matcher class TrainingAdministratorSpec extends ObjectBehavior { function it_should_have_an_array_as_roles() { $this->getRoles()->shouldBeArray(); $this->getRoles()->shouldContain('ROLE_COORDINATOR'); } function it_should_expose_display_data_bag() { $this->toDisplay()->shouldHaveKeyWithValue('name', 'Test User'); $this->toDisplay()->shouldHaveKey('name'); }
57. Inline Matcher class TrainingAdministratorSpec extends ObjectBehavior { function it_should_expose_display_data_bag() { $this->toDisplay()->shouldHaveKey('name'); } function getMatchers() { return [ 'haveKey' => function ($subject, $key) { return array_key_exists($key, $subject); }, ]; }
58. why phpspec?
59. why phpspec? - easy to write specs before code - does (some) code generation for you - helps to stay in the red-green-refactor loop - adds code level documentation - fun to use!
60. when not to use phpspec? - functional tests - use behat or phpunit - integration tests - use phpunit
61. how does it fit hexagonal arch? UI Adapter Log Adapter Data Storage Adapter External Data Adapter Application Domain
62. how does it fit hexagonal arch? UI Adapter Log Adapter Data Storage Adapter External Data Adapter Application Domain
63. What to spec? - simple answer: everything! - longer answer: - everything you can - but don’t use PhpSpec for integration/functional tests - leave it to Behat and/or PHP Unit
64. Use fakes for functional tests Fakes are simplified implementations of your infrastructure / external adapters. - e.g. InMemoryRepository will be a lot faster than Doctrine with mysql when run from inside VM!
65. Do test your infrastructure Write integration tests for your repositories and adapters. Always hide infrastructure / external services behind adapters.
66. Want to read more about phpspec? - github.com/phpspec/phpspec - phpspec.net - groups.google.com/forum/#!forum/phpspec-dev - twitter.com/phpsec
67. Questions?
68. Slides: speakerdeck.com/super_marek Give feedback: joind.in/14901 Connect: @super_marek Thank you!