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.
   

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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
   

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3. Whenever you are tempted
   to type something into a
   print statement or a
   debugger expression, write
   it as a test instead.
   – Martin Fowler
   “
   ”
   

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4. Benefits of Unit Testing
   •  Find problems early
   

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5. Benefits of Unit Testing
   •  Find problems early
   •  Facilitate refactoring
   

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6. Benefits of Unit Testing
   •  Find problems early
   •  Facilitate refactoring
   •  Simplify integration
   

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7. Benefits of Unit Testing
   •  Find problems early
   •  Facilitate refactoring
   •  Simplify integration
   •  Document usage
   

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8. Benefits of Unit Testing
   •  Find problems early
   •  Facilitate refactoring
   •  Simplify integration
   •  Document usage
   •  Design better interfaces
   

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9. Benefits of Unit Testing
   •  Find problems early
   •  Facilitate refactoring
   •  Simplify integration
   •  Document usage
   •  Design better interfaces
   confidence
   automation
   

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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
    

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11. PHP Testing Tools
    Test Frameworks
    •  PHPUnit *
    •  SimpleTest
    •  phpt
    Mocking
    •  PHPUnit
    •  Mockery
    •  Phake
    Code Coverage
    •  PHP_CodeCoverage
    •  Xdebug
    Other Testing
    •  Behat
    •  phpspec
    •  Selenium
    

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12. Other Types of Testing
    White-box Testing
    •  Unit
    •  Regression
    •  Integration
    •  Mutation
    Black-box Testing
    •  Acceptance
    •  Fuzz
    •  Smoke
    •  Performance
    – Load
    – Stress
    

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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.
    

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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
    

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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
    

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16. Best Practices
    •  Test one unit at a time
    

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17. Best Practices
    •  Test one unit at a time
    •  Make each test independent
    

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18. Best Practices
    •  Test one unit at a time
    •  Make each test independent
    •  Mock external state and services
    

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19. Best Practices
    •  Test one unit at a time
    •  Make each test independent
    •  Mock external state and services
    •  Name your tests after their intention
    

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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
    

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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
    

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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;  
           }  
    }  
    “
    ”
    

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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)
    

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24. TravisCI + GitHub PR = <3
    

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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
    

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26. People to Follow
    •  Sebastian Bergmann – @s_bergmann
    •  Martin Fowler – @martinfowler
    •  Miško Hevery – @mhevery
    •  Chris Hartjes – @grmpyprogrammer
    •  Konstantin Kudryashov – @everzet
    •  Jeff Carouth – @jcarouth
    

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27. Questions?
    Presentation by
    Jeremy Lindblom
    @jeremeamia
    

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