1. TDD in PHP:A Brief Example

2. About Me Jeremy Kendall PHP Developer since 2001 Organizer Memphis PHP Contributor to FRAPI project (getfrapi.com) [email_address] @JeremyKendall http://jeremykendall.net 3. TDD in PHP: A Brief Example Test Driven Development, you say? 4. Frankly, my dear . . . 5. Why You Should Give A Damn

Test Driven Development is perhaps one of the best and fastest ways to improve your understanding and command of object-oriented principles and best practices. Good design is testable, and design that isn't testable is bad. - Michael C. Feathers

6. What is TDD?

From Wikipedia:

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

Write a test

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

High cohesion, loose coupling

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

Tests only cover what you think should be tested

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

Live Coding?Really?Why?

22. TDD: Live Code Example

Goals

Practical example of TDD in action

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

Code example will test a fictional math tutor application

Calculator class

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

Calculator class

Adds one integer to another

28. Throws exceptions in the following cases:

Non-integer arguments provided

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

Tutor_Calculator_Interface

31. Tutor_Calculator_IntegerCalculator 32. TDD: Live Code Example

Tutor class

Verifies correct responses

33. Uses calculator class to test responses 34. Favors composition over inheritance 35. Tutor_MathTutor 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 a simple autoloader 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. Thanks!

[email_address] @JeremyKendall http://jeremykendall.net