Unit Testing

Brief overview of unit testing and an introduction to PHPUnit and other tools. For the Seattle PHP Meetup Group.

Transcript

1. Unit Testing Testing individual units of code to determine if they are fit for use.
2. Unit Testing Testing individual units of code to determine if they are fit for use. units The smallest testable part of an application. Functions Classes Methods
3. Whenever you are tempted to type something into a print statement or a debugger expression, write it as a test instead. – Martin Fowler “ ”
4. Benefits of Unit Testing •  Find problems early
5. Benefits of Unit Testing •  Find problems early •  Facilitate refactoring
6. Benefits of Unit Testing •  Find problems early •  Facilitate refactoring •  Simplify integration
7. Benefits of Unit Testing •  Find problems early •  Facilitate refactoring •  Simplify integration •  Document usage
8. Benefits of Unit Testing •  Find problems early •  Facilitate refactoring •  Simplify integration •  Document usage •  Design better interfaces
9. Benefits of Unit Testing •  Find problems early •  Facilitate refactoring •  Simplify integration •  Document usage •  Design better interfaces confidence automation
10. function  add($a,  $b)  {          return  $a  +  $b;   }     function  testAdd()  {          $cases  =  array(array(0,    0,  0),                            array(4,    2,  6),                            array(8,  -­‐1,  7));            foreach  ($cases  as  $case)  {                  list($a,  $b,  $c)  =  $case;                  assert('add($a,  $b)  ===  $c');          }   }     A Simple Example
11. PHP Testing Tools Test Frameworks •  PHPUnit * •  SimpleTest •  phpt Mocking •  PHPUnit •  Mockery •  Phake Code Coverage •  PHP_CodeCoverage •  Xdebug Other Testing •  Behat •  phpspec •  Selenium
12. Other Types of Testing White-box Testing •  Unit •  Regression •  Integration •  Mutation Black-box Testing •  Acceptance •  Fuzz •  Smoke •  Performance – Load – Stress
13. PHPUnit •  xUnit-style library by Sebastian Bergmann •  Well integrated and well documented •  Installable via Composer, PEAR, and Phar Features: •  Mocking •  Assertions •  Setup/teardown •  Annotations •  Data providers •  Code coverage •  Selenium integration •  Etc.
14. Anatomy of a Unit Test 1.  Setup & Fixtures 2.  Prepare input/state 3.  Execute the code being tested 4.  Assertions about output/state 5.  Teardown
15. Demo: AWS SDK for PHP 1.  Configuring and running PHPUnit 2.  Interpreting test output 3.  IDE Conveniences 4.  Examining code coverage 5.  Real test examples 6.  Update some tests https://github.com/aws/aws-sdk-php
16. Best Practices •  Test one unit at a time
17. Best Practices •  Test one unit at a time •  Make each test independent
18. Best Practices •  Test one unit at a time •  Make each test independent •  Mock external state and services
19. Best Practices •  Test one unit at a time •  Make each test independent •  Mock external state and services •  Name your tests after their intention
20. Best Practices •  Test one unit at a time •  Make each test independent •  Mock external state and services •  Name your tests after their intention •  Use good OOP and DRY principles
21. Best Practices •  Test one unit at a time •  Make each test independent •  Mock external state and services •  Name your tests after their intention •  Use good OOP and DRY principles •  Write your code to be testable
22. Dependency Injection Dependency Injection is where components are given their dependencies through their constructors, methods, or fields. class  Mailer  {          protected  $transport;          public  function  __construct(                  TransportInterface  $transport          )  {                  $this-­‐>transport  =  $transport;          }   }   “ ”
23. Continuous Integration (CI) •  Integrate code often and automate your build and test processes •  Continuous Integration Systems Jenkins CI • Travis CI • Xinc phpUnderControl • Bamboo •  More tools: phpmd, phpcpd, phpcs (see http://phpqatools.org)
24. TravisCI + GitHub PR = <3
25. TDD & BDD TDD – Test-driven development •  Tests are written before the implementation •  Short-development cycle; Agile methods •  Test-writing is part of the design process BDD – Behavior-driven development •  Extends TDD; focuses on acceptance testing •  Business requirements define behaviors •  Behat or phpspec are the main PHP tools
26. People to Follow •  Sebastian Bergmann – @s_bergmann •  Martin Fowler – @martinfowler •  Miško Hevery – @mhevery •  Chris Hartjes – @grmpyprogrammer •  Konstantin Kudryashov – @everzet •  Jeff Carouth – @jcarouth
27. Questions? Presentation by Jeremy Lindblom @jeremeamia