Is TDD dead? A cheeky guide to PhpSpec

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Is TDD dead? a cheeky guide to phpspec 12 August 2015

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Marek Matulka Software Engineer SensioLabs UK @super_marek

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no tests

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my first unit tests

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discovering BDD

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Write a failing scenario (feature)

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Write a failing scenario (feature) Write a failing test

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Write a failing scenario (feature) Write a failing test Make your test pass

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Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code

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Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Repeat the fail-pass-refactor cycle as necessary

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Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Make your feature pass

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Write a failing scenario (feature) Write a failing test Make your test pass Refactor your code Make your feature pass BDD TDD

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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

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Existing project $ composer require --dev phpspec/phpspec

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Starting new project? { "require-dev": { "phpspec/phpspec": "~2.0" }, "config": { "bin-dir": "bin" }, "autoload": {"psr-0": {"": "src"}} }

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first spec $ bin/phpspec desc Acme\\StringCalculator

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first spec $ bin/phpspec desc Acme\\StringCalculator Specification for Acme\StringCalculator created in /home/marek/Workspace/phpsw/spec/Acme/StringCalculatorSpec.php. $

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first spec $ bin/phpspec desc Acme\\StringCalculator Specification for Acme\StringCalculator created in /home/marek/Workspace/phpsw/spec/Acme/StringCalculatorSpec.php. $ bin/phpspec run

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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]

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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 $

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spec/Acme/StringCalculatorSpec.php shouldHaveType('Acme\StringCalculator'); } }

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src/Acme/StringCalculator.php

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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); } }

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$ bin/phpspec run Do you want me to create `Acme\StringCalculator::calculate()` for you? [Y/n] Method Acme\StringCalculator::calculate() has been created. $

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$ 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. $

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$ 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

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src/Acme/StringCalculator.php

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$ 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

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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); } }

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stub

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namespace Acme; interface LearnerRepository { /** * @param integer $id * * @return Learner */ public function findLearnerById($id); }

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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); } }

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mock

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namespace Acme; interface MessageDispatcher { /** * @param integer $id * * @return Message */ public function dispatch(Message $message); }

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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); } }

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spy

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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(); } }

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constructing objects

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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... }

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class LearnerSpec extends ObjectBehaviour { function let() { $this->beConstractedThrough( 'fromEmail', ['user@example.com'] ); } }

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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'); }

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matchers

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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"); }

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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(''); } }

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Throw Matcher class TrainingAdministratorSpec extends ObjectBehavior { function it_should_not_allow_empty_name() { $this->beConstructedWith(''); $this->shouldThrow('\InvalidArgumentException') ->duringInstantiation(); } }

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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); } }

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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'); } }

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Count Matcher class TrainingAdministratorSpec extends ObjectBehavior { function it_should_have_one_role() { $this->getRoles()->shouldHaveCount(1); } }

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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'); } }

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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'); }

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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); }, ]; }

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why phpspec?

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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!

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when not to use phpspec? - functional tests - use behat or phpunit - integration tests - use phpunit

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how does it fit hexagonal arch? UI Adapter Log Adapter Data Storage Adapter External Data Adapter Application Domain

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how does it fit hexagonal arch? UI Adapter Log Adapter Data Storage Adapter External Data Adapter Application Domain

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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

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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!

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Do test your infrastructure Write integration tests for your repositories and adapters. Always hide infrastructure / external services behind adapters.

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Want to read more about phpspec? - github.com/phpspec/phpspec - phpspec.net - groups.google.com/forum/#!forum/phpspec-dev - twitter.com/phpsec

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Questions?

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Slides: speakerdeck.com/super_marek Give feedback: joind.in/14901 Connect: @super_marek Thank you!