Your code are my tests

After years of promoting PHPUnit I still hear it's hard to get started with unit testing. So instead of showing nice step-by-step examples on how to use PHPUnit, we're going to take an example straight from github.

So I take on the challenge to start writing tests for PHP projects that don't have unit tests in place and explain how I decide where to begin, how I approach my test strategy and how I ensure I’m covering each possible use case (and covering the CRAP index).

The goal of this presentation is to show everyone that even legacy code, spaghetti code and complex code bases can be tested. After this talk you can immediately apply my examples on your own codebase (even if it's a clean code base) and get started with testing.

Transcript

1. 2
   Your  code  are  my  tests
   PHP-­‐WVL  
   Brugge,  Belgium
   

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2. 2
   ADVISORY
   IN ORDER TO EXPLAIN CERTAIN SITUATIONS YOU MIGHT FACE IN YOUR
   DEVELOPMENT CAREER, WE WILL BE DISCUSSING THE USAGE OF
   PRIVATES AND PUBLIC EXPOSURE. IF THESE TOPICS OFFEND OR
   UPSET YOU, WE WOULD LIKE TO ASK YOU TO LEAVE THIS ROOM NOW.
   !
   THE SPEAKER NOR THE ORGANISATION CANNOT BE HELD
   ACCOUNTABLE FOR MENTAL DISTRESS OR ANY FORMS OF DAMAGE
   YOU MIGHT ENDURE DURING OR AFTER THIS PRESENTATION. FOR
   COMPLAINTS PLEASE INFORM ORGANISATION AT INFO@PHP-WVL.BE.
   

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3. 3
   Michelangelo van Dam!
   !
   PHP Consultant
   Community Leader
   President of PHPBenelux
   Contributor
   

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4. Why  bother  with  tes-ng?
   4
   https://www.flickr.com/photos/vialbost/5533266530
   

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5. Reasons  why  not  to  test
   • No  4me  
   • No  budget  
   • We  deliver  tests  a;er  delivery  (  this  means  never  )  
   • We  don’t  know  how…
   5
   

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6. No  excuses!!!
   6
   Crea4ve  Commons  -­‐  hFp://www.flickr.com/photos/akrabat/8421560178
   

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7. Responsibility  issue
   • As  a  developer,  it’s  your  job  to  
   • write  code  &  fixing  bugs  
   • add  documenta4on  
   • write  &  update  unit  tests
   7
   

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8. Pizza  principle
   8
   Topping:  your  tests
   Box:  your  documenta4on
   Dough:  your  code
   

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9. Benefits  of  tes-ng
   • Direct  feedback  (test  fails)  
   • Once  a  test  is  made,  it  will  always  be  tested  
   • Easy  to  refactor  exis4ng  code  (protec4on)  
   • Easy  to  debug:  write  a  test  to  see  if  a  bug  is  genuine  
   • Higher  confidence  and  less  uncertainty
   9
   

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10. Rule  of  thumb
    “Whenever   you   are   tempted   to   type   something   into   a   print  
    statement  or  a  debugger  expression,  write  it  as  a  test  instead.”  
    !
    —  Source:  Mar?n  Fowler
    10
    

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11. Warming  up
    11
    https://www.flickr.com/photos/bobjagendorf/8535316836
    

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12. PHPUnit
    • PHPUnit  is  a  port  of  xUnit  tes4ng  framework  
    • Created  by  “Sebas4an  Bergmann”  
    • Uses  “asser4ons”  to  verify  behaviour  of  “unit  of  code”  
    • Open  source  and  hosted  on  GitHub  
    • See  hFps://github.com/sebas4anbergmann/phpunit  
    • Can  be  installed  using:  
    • PEAR  
    • PHAR  
    • Composer
    12
    

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13. Approach  for  tes-ng
    • Instan4ate  a  “unit-­‐of-­‐code”  
    • Assert  expected  result  against  actual  result  
    • Provide  a  custom  error  message
    13
    

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14. Available  asser-ons
    • assertArrayHasKey()  
    • assertClassHasAFribute()  
    • assertClassHasSta4cAFribute()  
    • assertContains()  
    • assertContainsOnly()  
    • assertContainsOnlyInstancesOf()  
    • assertCount()  
    • assertEmpty()  
    • assertEqualXMLStructure()  
    • assertEquals()  
    • assertFalse()  
    • assertFileEquals()  
    • assertFileExists()  
    • assertGreaterThan()  
    • assertGreaterThanOrEqual()  
    • assertInstanceOf()  
    • assertInternalType()  
    • assertJsonFileEqualsJsonFile()  
    • assertJsonStringEqualsJsonFile()  
    • assertJsonStringEqualsJsonString()  
    • assertLessThan()  
    • assertLessThanOrEqual()  
    • assertNull()  
    • assertObjectHasAFribute()  
    • assertRegExp()  
    • assertStringMatchesFormat()  
    • assertStringMatchesFormatFile()  
    • assertSame()  
    • assertSelectCount()  
    • assertSelectEquals()  
    • assertSelectRegExp()  
    • assertStringEndsWith()  
    • assertStringEqualsFile()  
    • assertStringStartsWith()  
    • assertTag()  
    • assertThat()  
    • assertTrue()  
    • assertXmlFileEqualsXmlFile()  
    • assertXmlStringEqualsXmlFile()  
    • assertXmlStringEqualsXmlString()
    14
    

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15. To  protect  and  to  serve
    15
    

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16. Data  is  tainted,  ALWAYS
    16
    Hack
    er
    s BAD DATA
    W
    eb Services
    Stupid users
    

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19. OWASP  top  10  exploits
    19
    https://www.owasp.org/index.php/Top_10_2013-Top_10
    

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20. Filtering  &  Valida-on
    20
    

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21. Smallest  unit  of  code
    21
    https://www.flickr.com/photos/toolstop/4546017269
    

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22. Example  class
    /** !
    * Example class !
    */ !
    class MyClass !
    { !
    /** ... */ !
    public function doSomething($requiredParam, $optionalParam = null) !
    { !
    if (!filter_var( !
    $requiredParam, FILTER_SANITIZE_STRING, FILTER_FLAG_ENCODE_HIGH !
    )) { !
    throw new InvalidArgumentException('Invalid argument provided'); !
    } !
    if (null !== $optionalParam) { !
    if (!filter_var( !
    $optionalParam, FILTER_SANITIZE_STRING, FILTER_FLAG_ENCODE_HIGH !
    )) { !
    throw new InvalidArgumentException('Invalid argument provided'); !
    } !
    $requiredParam .= ' - ' . $optionalParam; !
    } !
    return $requiredParam; !
    } !
    }
    22
    

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23. Tes-ng  for  good
    /** ... */!
    public function testClassAcceptsValidRequiredArgument() !
    { !
    $expected = $argument = 'Testing PHP Class'; !
    $myClass = new MyClass; !
    $result = $myClass->doSomething($argument); !
    $this->assertSame($expected, $result, !
    'Expected result differs from actual result'); !
    } !
    !
    /** ... */ !
    public function testClassAcceptsValidOptionalArgument() !
    { !
    $requiredArgument = 'Testing PHP Class'; !
    $optionalArgument = 'Is this not fun?!?'; !
    $expected = $requiredArgument . ' - ' . $optionalArgument; !
    $myClass = new MyClass; !
    $result = $myClass->doSomething($requiredArgument, $optionalArgument); !
    $this->assertSame($expected, $result, !
    'Expected result differs from actual result'); !
    }
    23
    

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24. Tes-ng  for  bad
    /** !
    * @expectedException InvalidArgumentException !
    */ !
    public function testExceptionIsThrownForInvalidRequiredArgument() !
    { !
    $expected = $argument = new StdClass; !
    $myClass = new MyClass; !
    $result = $myClass->doSomething($argument); !
    $this->assertSame($expected, $result, !
    'Expected result differs from actual result'); !
    } !
    !
    /** !
    * @expectedException InvalidArgumentException !
    */ !
    public function testExceptionIsThrownForInvalidOptionalArgument() !
    { !
    $requiredArgument = 'Testing PHP Class'; !
    $optionalArgument = new StdClass; !
    $myClass = new MyClass; !
    $result = $myClass->doSomething($requiredArgument, $optionalArgument); !
    $this->assertSame($expected, $result, !
    'Expected result differs from actual result'); !
    }
    24
    

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25. We  don’t  live  in  a  fairy  tale!
    25
    https://www.flickr.com/photos/bertknot/8175214909
    

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26. Real  code,  real  apps
    26
    

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27. github.com/Telaxus/EPESI
    27
    

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28. Running  the  project
    28
    

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29. Where  are  the  TESTS?
    29
    

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30. Where  are  the  TESTS?
    30
    

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31. Oh  noes,  no  tests!
    31
    https://www.flickr.com/photos/mjhagen/2973212926
    

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32. Let’s  get  started
    32
    https://www.flickr.com/photos/npobre/2601582256
    

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33. How  to  get  about  it?
    33
    

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34. Se\ng  up  for  tes-ng
    !
    !
    !
    tests/admin!
    !
    !
    tests/include!
    !
    !
    tests/modules!
    !
    !
    !
    !
    !
    !
    !
    !
    !
    !
    !
    
    34
    

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35. ModuleManager
    • not_loaded_modules  
    • loaded_modules  
    • modules  
    • modules_install  
    • modules_common  
    • root  
    • processing  
    • processed_modules  
    • include_install  
    • include_common  
    • include_main  
    • create_load_priority_array  
    • check_dependencies  
    • sa4sfy_dependencies  
    • get_module_dir_path  
    • get_module_file_name  
    • list_modules  
    • exists  
    • register  
    • unregister  
    • is_installed  
    • upgrade  
    • downgrade  
    • get_module_class_name  
    • install  
    • uninstall  
    • get_processed_modules  
    • get_load_priority_array  
    • new_instance  
    • get_instance  
    • create_data_dir  
    • remove_data_dir  
    • get_data_dir  
    • load_modules  
    • create_common_cache  
    • create_root  
    • check_access  
    • call_common_methods  
    • check_common_methods  
    • required_modules  
    • reset_cron
    35
    

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36. ModuleManager::module_install
    /** !
    * Includes file with module installation class. !
    * !
    * Do not use directly. !
    * !
    * @param string $module_class_name module class name - underscore separated !
    */ !
    public static final function include_install($module_class_name) { !
    if(isset(self::$modules_install[$module_class_name])) return true; !
    $path = self::get_module_dir_path($module_class_name); !
    $file = self::get_module_file_name($module_class_name); !
    $full_path = 'modules/' . $path . '/' . $file . 'Install.php'; !
    if (!file_exists($full_path)) return false; !
    ob_start(); !
    $ret = require_once($full_path); !
    ob_end_clean(); !
    $x = $module_class_name.'Install'; !
    if(!(class_exists($x, false)) || !
    !array_key_exists('ModuleInstall',class_parents($x))) !
    trigger_error('Module '.$path.': Invalid install file',E_USER_ERROR); !
    self::$modules_install[$module_class_name] = new $x($module_class_name); !
    return true; !
    }
    36
    

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37. Tes-ng  first  condi-on
    !
    require_once 'include.php'; !
    !
    class ModuleManagerTest extends PHPUnit_Framework_TestCase !
    { !
    protected function tearDown() !
    { !
    ModuleManager::$modules_install = array (); !
    } !
    !
    public function testReturnImmediatelyWhenModuleAlreadyLoaded() !
    { !
    $module = 'Foo_Bar'; !
    ModuleManager::$modules_install[$module] = 1; !
    $result = ModuleManager::include_install($module); !
    $this->assertTrue($result, !
    'Expecting that an already installed module returns true'); !
    $this->assertCount(1, ModuleManager::$modules_install, !
    'Expecting to find 1 module ready for installation'); !
    } !
    }
    37
    

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38. Run  test
    38
    

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39. Check  coverage
    39
    

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40. Test  for  second  condi-on
    public function testLoadingNonExistingModuleIsNotExecuted() !
    { !
    $module = 'Foo_Bar'; !
    $result = ModuleManager::include_install($module); !
    $this->assertFalse($result, 'Expecting failure for loading Foo_Bar'); !
    $this->assertEmpty(ModuleManager::$modules_install, !
    'Expecting to find no modules ready for installation'); !
    }
    40
    

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41. Run  tests
    41
    

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42. Check  coverage
    42
    

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43. Test  for  third  condi-on
    public function testNoInstallationOfModuleWithoutInstallationClass() !
    { !
    $module = 'EssClient_IClient'; !
    $result = ModuleManager::include_install($module); !
    $this->assertFalse($result, 'Expecting failure for loading Foo_Bar'); !
    $this->assertEmpty(ModuleManager::$modules_install, !
    'Expecting to find no modules ready for installation'); !
    }
    43
    

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44. Run  tests
    44
    

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45. Check  code  coverage
    45
    

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46. Non-­‐executable  code
    46
    https://www.flickr.com/photos/dazjohnson/7720806824
    

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47. Test  for  success
    public function testIncludeClassFileForLoadingModule() !
    { !
    $module = 'Base_About'; !
    $result = ModuleManager::include_install($module); !
    $this->assertTrue($result, 'Expected module to be loaded'); !
    $this->assertCount(1, ModuleManager::$modules_install, !
    'Expecting to find 1 module ready for installation'); !
    }
    47
    

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48. Run  tests
    48
    

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49. Check  code  coverage
    49
    

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50. Look  at  the  global  coverage
    50
    

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51. Bridging  gaps
    51
    https://www.flickr.com/photos/hugo90/6980712643
    

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52. Privates  exposed
    52
    http://www.slashgear.com/former-tsa-agent-admits-we-knew-full-body-scanners-didnt-work-31315288/
    

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53. Dependency
    • __construct  
    • get_module_name  
    • get_version_min  
    • get_version_max  
    • is_sa4sfied_by  
    • requires  
    • requires_exact  
    • requires_at_least  
    • requires_range
    53
    

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54. A  private  constructor!
    !
    defined("_VALID_ACCESS") || die('Direct access forbidden'); !
    !
    /** !
    * This class provides dependency requirements !
    * @package epesi-base !
    * @subpackage module !
    */ !
    class Dependency { !
    !
    private $module_name; !
    private $version_min; !
    private $version_max; !
    private $compare_max; !
    !
    private function __construct(!
    $module_name, $version_min, $version_max, $version_max_is_ok = true) { !
    $this->module_name = $module_name; !
    $this->version_min = $version_min; !
    $this->version_max = $version_max; !
    $this->compare_max = $version_max_is_ok ? '<=' : '<'; !
    } !
    !
    /** ... */ !
    }
    54
    

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55. Don’t  touch  my  junk!
    55
    https://www.flickr.com/photos/caseymultimedia/5412293730
    

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56. House  of  Reflec-on
    56
    https://www.flickr.com/photos/tabor-roeder/8250770115
    

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57. Let’s  do  this…
    require_once 'include.php'; !
    !
    class DependencyTest extends PHPUnit_Framework_TestCase !
    { !
    public function testConstructorSetsProperSettings() !
    { !
    require_once 'include/module_dependency.php'; !
    !
    // We have a problem, the constructor is private!!
    } !
    }
    57
    

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58. Let’s  use  the  sta-c
    $params = array ( !
    'moduleName' => 'Foo_Bar', !
    'minVersion' => 0, !
    'maxVersion' => 1, !
    'maxOk' => true, !
    ); !
    // We use a static method for this test !
    $dependency = Dependency::requires_range( !
    $params['moduleName'], !
    $params['minVersion'], !
    $params['maxVersion'], !
    $params['maxOk'] !
    ); !
    !
    // We use reflection to see if properties are set correctly !
    $reflectionClass = new ReflectionClass('Dependency');
    58
    

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59. Use  the  reflec-on  to  assert
    // Let's retrieve the private properties !
    $moduleName = $reflectionClass->getProperty('module_name'); !
    $moduleName->setAccessible(true); !
    $minVersion = $reflectionClass->getProperty('version_min'); !
    $minVersion->setAccessible(true); !
    $maxVersion = $reflectionClass->getProperty('version_max'); !
    $maxVersion->setAccessible(true); !
    $maxOk = $reflectionClass->getProperty('compare_max'); !
    $maxOk->setAccessible(true); !
    !
    // Let's assert !
    $this->assertEquals($params['moduleName'], $moduleName->getValue($dependency), !
    'Expected value does not match the value set’);!
    !
    $this->assertEquals($params['minVersion'], $minVersion->getValue($dependency), !
    'Expected value does not match the value set’);!
    !
    $this->assertEquals($params['maxVersion'], $maxVersion->getValue($dependency), !
    'Expected value does not match the value set’);!
    !
    $this->assertEquals('<=', $maxOk->getValue($dependency), !
    'Expected value does not match the value set');
    59
    

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60. Run  tests
    60
    

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61. Code  Coverage
    61
    

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62. Yes,  paradise  exists
    62
    https://www.flickr.com/photos/rnugraha/2003147365
    

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63. Unit  tes-ng  is  not  difficult!
    63
    

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64. You  just  need  to  get  started
    64
    

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65. PHP  has  all  the  tools
    65
    

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66. And  there  are  more    
    roads  to  Rome
    66
    

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67. Recommended  reading
    67
    

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68. Need  help?
    68
    Michelangelo van Dam
    !
    michelangelo@in2it.be
    @DragonBe
    www.in2it.be
    

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69. Ques-ons?
    69
    https://www.flickr.com/photos/mdpettitt/8671901426
    

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70. 70
    joind.in/11363!
    !
    If you liked my talk, thanks.
    If not, let me know how to improve it
    

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