1. TDD in PHP:A Brief Example

2. About Me Jeremy Kendall PHP Developer since 2001 Organizer Memphis PHP Author at http://csiphp.com [email_address] @JeremyKendall http://about.me/jeremykendall 3. TDD in PHP: A Brief Example Test Driven Development, you say? 4. Frankly, my dear . . . 5. Frankly, my dear . . . 6. Why You Should Give A Damn

Good design is testable, and design that isn't testable is bad. Michael C. Feathers

7. What is TDD?

From Wikipedia:

8. Test Driven Development (TDD)is a software development process that relies on the repetition of a very short development cycle. . . 9. TDD Development Process

Write a test

10. Run all tests, watch new test fail 11. Write just enough code to make the test pass 12. Run all tests, watch new test pass 13. Lather, rinse, repeat . . . 14. Refactor 15. TDD: The Benefits

High cohesion, loose coupling

16. Confidence 17. Faster time to resolution 18. Documentation 19. TDD: The Drawbacks

Tests only cover what you think should be tested

20. False sense of confidence 21. Without management and team buy-in, TDD is DOA 22. TDD: Live Code Example

Live Coding?Really?Why?

23. TDD: Live Code Example

Goals

Practical example of TDD in action

24. Demonstrate refactoring with confidence 25. Demonstrate TDD impact on design decisions 26. TDD: Live Code Example

Code example will test a fictional math tutor application

Calculator class

27. Tutor class (consumes calculator) 28. TDD: Live Code Example

Calculator class

Adds one integer to another

29. Throws exceptions in the following cases:

Non-integer arguments provided

30. Integer overflow 31. Integer underflow Code to interface not implementation

TutorCalculatorCalculatorInterface

32. TutorCalculatorIntegerCalculator 33. TDD: Live Code Example

Tutor class

Verifies correct responses

34. Uses calculator class(es) to test responses 35. Favors composition over inheritance TutorMathTutor

_construct(CalculatorInterface $c)

36. TDD: Live Code Example

We'll be using PHPUnit

37. PHPUnit will be configured with phpunit.xml 38. phpunit.xml:

Calls bootstrap.php

39. Tells PHPUnit where to look for our tests 40. Code coverage and testdox reports bootstrap.php:

Adds our library to the include path

41. Registers simple autoloaders 42. LET'S GET IT ON! 43. Resources

Test Driven Development at Wikipedia -http://bit.ly/9Aa3Xr

44. PHPUnit -http://www.phpunit.de/ 45. Xdebug - http://www.xdebug.org/ 46. The code example in this presentation was adapted for PHP from Przemysaw Bielicki's TDD video tutorial at Agile Software Development. -http://bit.ly/byDZOA 47. Resources 48. Resources s 49. Resources 50. Thanks!

[email_address] @JeremyKendall http://about.me/jeremykendall