BDD For The Rest of Us - TarnovoConf 2017

Transcript

1. BDD For The Rest of Us 1
2. $> whoami Boyan Yordanov Twitter: @specter_bg Organizer of PHP Varna Member of VarnaLab Developer @ ShtrakBG 2
3. Confession Time 3
4. 4
5. ... "Testing is critical for quality" 5
6. How are you testing? 1. Make a change 2. Switch to a browser / application / console 3. Click around to see the new thing 4. Check that nothing is broken? 6
7. 7
8. Once we know there is a problem only then we can x it. 8
9. What can we do about it? We can automate 9
10. The computer is always faster than you * and doesn't make mistakes ** * almost always ** and not really 10
11. 11
12. Types of Automated Testing Unit Test Integration Tests Acceptance (End-To-End) Tests 12
13. Which type to use? All of them 13
14. 14
15. Testing is important Figuring out what to test and how to test it is even more important 15
16. -- almost everyone But my PM/boss/client/cat thinks that all this is a waste of time and money 16
17. Behaviour Driven Development 17 . 1
18. Isn't BDD the same as TDD? 17 . 2
19. -- Dan North Yes. If you’re a programmer, and your entire team is programmers, and all your stakeholders are programmers and you have a single Subject Matter Expert embedded in the team. dannorth.net/2012/05/31/bdd-is-like-tdd-if/ 17 . 3
20. Think about the behaviour of the system Have conversations with the product owner / manager / client Together come up with examples of the correct behaviour Write the examples down and then write test code 17 . 4
21. -- Liz Keogh Having conversations is more important than capturing conversations is more important than automating conversations 17 . 5
22. Gherkin A Business Readable, Domain Speci c Language that lets you describe behaviour. behat.org/en/latest/user_guide/gherkin.html 18 . 1
23. Feature: Generate reports for a conference Scenario: Report for the attendees at VarnaConf Given there is a conference "VarnaConf" And it has 150 attendees When I generate a report Then it should have 150 rows And each row should contain the attendee's name 18 . 2
24. A Gherkin feature: describes the behaviour to be added business people understand it as well is not concerned with the actual implementation bonus: can be used as documentation 18 . 3
25. It's so cool, the bussiness people can write it too! 19
26. So who should write the features? 20
27. Meet the three amigos * the domain Expert the developer the tester * in an ideal world in which you have all of them on your team 21
28. Writing a feature Feature: Generate reports for a conference Scenario: Report for the attendees at VarnaConf Given there is a conference "VarnaConf" And it has 150 attendees When I generate a report Then it should have 150 rows And each row should contain the attendee's name 22 . 1
29. Feature: Generate reports for a conference Scenario: Report for the attendees at VarnaConf Given there is a conference "VarnaConf" And it has 150 attendees When I generate a report Then it should have 150 rows And each row should contain the attendee's name 22 . 2
30. Feature: Generate reports for a conference Scenario: Report for the attendees at VarnaConf Given there is a conference "VarnaConf" And it has 150 attendees When I generate a report Then it should have 150 rows And each row should contain the attendee's name 22 . 3
31. Feature: Generate reports for a conference Scenario: Report for the attendees at VarnaConf Given there is a conference "VarnaConf" And it has 150 attendees When I generate a report Then it should have 150 rows And each row should contain the attendee's name 22 . 4
32. Common pitfals not completely wrong, just not as good 23 . 1
33. Thinking that BDD is only for End-To-End testing Feature: Generate reports for a conference Scenario: Report for the attendees at VarnaConf Given there is a conference "VarnaConf" And it has 150 attendees When I go to "/reports/1" And I press the "Generate Attendees Report" button Then I should be on "/reports/1/attendees" And I should see "Attendees Report for VarnaConf" And I should see "Name" And I should see "Boyan" 23 . 2
34. What's the problem here? too tied to the UI and web browser easy to break, hard to reuse does not describe the feature well enough 23 . 3
35. Describing API endpoints this was actually good Feature: Generate reports for a conference Scenario: Report for the attendees at VarnaConf Given there is a conference "VarnaConf" And it has 150 attendees When I request GET "/reports/1/attendees" Then the response status should be 200 And the content type should be "application/json" And the response should have the structure: """ some json structure ... """ 23 . 4
36. describes the request well enough still not reusable to drive just the domain possibly slow because of the required http request Today: just use API Bluepring or Swagger with a tool for contract testing 23 . 5
37. How are we going to get from plain English to actual tests? 24
38. Tools Java: JBehave PHP: Behat, PHPSpec Ruby: Cucumber, RSpec Python: Lettuce, Behave JavaScript: Cucumber.js, Yadda .NET: SpecFlow 25
39. Behat "A PHP framework for autotesting your bussiness expectations" behat.org 26
40. Behat Contexts Match Gherkin with actual test code Just PHP classes Can hook into Behat's lifecycle 27
41. Create a context and use hooks use Behat\Behat\Context\Context; class FeatureContext implements Context { /** @BeforeScenario */ public function someSetupForTheScenario() { // set up fakes, db, browser etc. } } 28 . 1
42. De ning Steps /** @Given there is a conference :conferenceName */ public function thereIsAConference($conferenceName) { $this->conference = new Conference("VarnaConf"); } 28 . 2
43. /** @When I generete a report */ public function iGenerateReport() { $this->report = new Report($this->conference); } 28 . 3
44. Making assertions use PHPUnit\Framework\Assert; // ... /** @Then it should have :expectedNumber rows */ public function itShouldHaveRows($expectedNumber) { Assert::assertCount( $expectedNumber, $this->report->getRows(), "The report does not have the expected number of rows." ) } 28 . 4
45. It's all about the context class WebContext extends RawMinkContext { /** @When I generate a report */ public function iGenerateReport() { $browser = $this->getSession(); $browser->visit("/reports/{$this->conferenceId}"); $browser->pressButton("#showAttendeesReport"); } // ... } 29
46. -- Uncle Bob "The only way to go fast is to go well." 30
47. Resources Introducing BDD - Dan North BDD is like TDD if… - Dan North 10 years of Doing Behaviour-Driven Development All Wrong by Liz Keogh Getting out of end-to-end testing jail - Konstantin Kudryashov Driving Design through Examples - Ciaran McNulty https://dannorth.net/introducing-bdd/ https://dannorth.net/2012/05/31/bdd-is-like-tdd-if Part 1: https://www.youtube.com/watch?v=2EM4itu7j7I Part 2: https://www.youtube.com/watch?v=AFCdE5KSREI https://skillsmatter.com/skillscasts/9142-a-talk-by-konstantin-kudryashov https://www.youtube.com/watch?v=83GbyDpJDI4 31
48. Thank You http://bit.ly/tarnovoconf-17-bdd 32