Automated Testing with PHPUnit

1. Automated Testing with PHPUnit

2. How do you know your code works?

3. Manual Testing • Type in a value • Submit the form • Check by eye

4. Manual Testing • Tedious • Time Consuming • Error Prone • Did you test everything? • Consistently?

5. Automated Testing Have the computer run your tests

6. Pro: Confidence Know that your code does what it needs to Know that your code doesn’t break anything that used to work Regression Testing

7. Con: Testing isn’t free • Writing tests takes time • Response: So does manual testing • Mo Code Mo Problems • Response: It’s a worthwhile investment

8. Unit Testing Automated testing one unit at a time

9. What is a unit? Module (procedural programming) Class (OOP)

10. Breaking Down Unit Tests • Test Suite composed of • Test Case Classes each of which have • Test Methods which make 1 or more • Assertions

11. A Unit Test Asserts That A Unit Of Code Performs To A Specification

12. XUnit Frameworks Help

13. XUnit Frameworks Provide • Assertions • Calls Test Methods • Help Setup • Test Cases • Test Runners

14. Assertions • Code to verify that expected and actual values match • Often methods starting with “assert…()” or “refute…()” • Used by the developer • $this->assertTrue() • $this-> assertFalse() • $this-> assertEquals()

15. Calls Test Methods • Knows to call your code which tests a particular condition, method, or other “sub unit” • Methods usually begin with “Test…()” • Written by the developer • class … { • public function test…() • { • … • } • }

16. Help setUp and tearDown • Offers special functions that get called before and after each test. • Written by the developer • class … { • public function • setUp() {…} • public function tearDown() {…} • }

17. Unit Test Life Cycle

18. Test Case • A class with test methods • Usually offers assert methods • Extended by the developer • class MyTestextends PHPUnit_Framework_ TestCase • { • … • }

19. Provide Test Runners Code that makes executing tests simple Often a command-line tool (useable by IDE)

20. Test First or Test Last?

21. Test First Test Driven Development (TDD)

22. Testing Cycle

23. Find Problems Early How should your code work? What do the requirements mean?

24. Manage Scope Creep Do The Simplest Thing That Could Possibly Work YAGNI Know when you’re done: All tests are green.

25. Test Last Problematic Tests become biased for the code you already wrote

26. What don’t you test?

27. Don’t Test the Language/Framework • Don’t test session session initiaiton • Or $_POST/$_GET/etc. • Or anything provided by PHP (and/or your framework, • $_POST[“loggedIn”] = true; • $this-> assertTrue($_POST [“loggedIn”]) • # Wrong!

28. Don’t Test Methods Without Logic • class … { • private $foo; • public get_foo() { • return $this->foo; • } • }

29. What to Test

30. Boundaries • function … { • if ($foo > 3) { • // test whether execution goes in here • } • else { • // test whether execution goes in here • } • }

31. Invalid values • 0 • Negative values • Empty strings • Very long strings (>500chars)

32. What’s a good test? • Repeatable • Use setUp() to make sure everything is right for your test • Independent • UsetearDown() to clean up • Thorough • It’s ok to have more than one test method in your case… in fact it’s often necessary!