1. Testing untestable code
Stephan Hochdörfer, bitExpert AG

2. Testing untestable code
About me
 Stephan Hochdörfer, bitExpert AG
 Department Manager Research Labs
 enjoying PHP since 1999
 S.Hochdoerfer@bitExpert.de
 @shochdoerfer

3. Testing untestable code
No excuse for writing bad code!

6. Testing untestable code
"Hang the rules. They're more like
guidelines anyway."
Elizabeth Swann, Pirates of the Caribbean

7. Testing untestable code
"There is no secret to writing tests,
there are only secrets to write
testable code!"
Miško Hevery

8. Testing untestable code
What is „untestable code“?

14. Testing untestable code
"...our test strategy requires us to
have more control [...] of the sut."
Gerard Meszaros, xUnit Test Patterns: Refactoring Test
Code

15. Testing untestable code
In a perfect world...
Unittest
Unittest SUT
SUT

16. Testing untestable code
Legacy code is not perfect...
Dependency
Dependency
Unittest
Unittest SUT
SUT
Dependency
Dependency

17. Testing untestable code
...
Legacy code is not perfect...
Dependency
Dependency
Unittest
Unittest SUT
SUT
Dependency
Dependency
...

18. Testing untestable code
...
Legacy code is not perfect...
Dependency
Dependency
Unittest
Unittest SUT
SUT
Dependency
Dependency
...

19. Testing untestable code
How to get „testable“ code?

20. Testing untestable code
How to get „testable“ code?
Refactoring

21. Testing untestable code
"Before you start refactoring, check
that you have a solid suite of
tests."
Martin Fowler, Refactoring

23. Testing untestable code
Which path to take?

24. Testing untestable code
Which path to take?
Do not change existing code!

25. Testing untestable code
Examples
Object Construction External resources Language issues

26. Testing untestable code
Object construction
<?php
class Car {
private $Engine;
public function __construct($sEngine) {
$this­>Engine = Engine::getByType($sEngine);
}
}

27. Testing untestable code
Object construction - Autoload
<?php
function run_autoload($psClass) {
$sFileToInclude = strtolower($psClass).'.php';
if(strtolower($psClass) == 'engine') {
$sFileToInclude = '/custom/mocks/'.
$sFileToInclude;
}
include($sFileToInclude);
}
// Testcase
spl_autoload_register('run_autoload');
$oCar = new Car('Diesel');
echo $oCar­>run();

28. Testing untestable code
Object construction
<?php
include('Engine.php');
class Car {
private $Engine;
public function __construct($sEngine) {
$this­>Engine = Engine::getByType($sEngine);
}
}

29. Testing untestable code
Object construction - include_path
<?php
ini_set('include_path',
'/custom/mocks/'.PATH_SEPARATOR.
ini_get('include_path'));
// Testcase
include('car.php');
$oCar = new Car('Diesel');
echo $oCar­>run();

30. Testing untestable code
Object construction – Stream Wrapper
<?php
class CustomWrapper {
private $_handler;
function stream_open($path, $mode, $options,
&$opened_path) {
stream_wrapper_restore('file');
// @TODO: modify $path before fopen
$this­>_handler = fopen($path, $mode);
stream_wrapper_unregister('file');
stream_wrapper_register('file', 'CustomWrapper');
return true;
}
}

31. Testing untestable code
Object construction – Stream Wrapper
stream_wrapper_unregister('file');
stream_wrapper_register('file', 'CustomWrapper');

32. Testing untestable code
Object construction – Stream Wrapper
<?php
class CustomWrapper {
private $_handler;
function stream_read($count) {
$content = fread($this­>_handler, $count);
$content = str_replace('Engine::getByType',
'AbstractEngine::get', $content);
return $content;
}
}

33. Testing untestable code
External resources

34. Testing untestable code
External resources
Database Webservice
Filesystem Mailserver

35. Testing untestable code
External resources – Mock database

36. Testing untestable code
External resources – Mock database
Provide own implementation

37. Testing untestable code
External resources – Mock database
ZF1 example:
$db = new Custom_Db_Adapter(array());
Zend_Db_Table::setDefaultAdapter($db);

38. Testing untestable code
External resources – Mock database
PHPUnit_Extensions_Database_TestCase

39. Testing untestable code
External resources – Mock database
require_once "PHPUnit/Extensions/Database/TestCase.php"
class MySampleTest extends
PHPUnit_Extensions_Database_TestCase
{
public function getConnection() {
$pdo = new PDO('sqlite::memory:');
return $this­>createDefaultDBConnection(
$pdo,
':memory:'
);
}
public function getDataSet() {
return $this­>createFlatXMLDataSet(
dirname(__FILE__).'/_files/data.xml'
);
}
}

40. Testing untestable code
External resources – Mock database
Proxy for your SQL Server

41. Testing untestable code
External resources – Mock webservice

42. Testing untestable code
External resources – Mock webservice
Provide own implementation

43. Testing untestable code
External resources – Mock webservice
Host redirect via /etc/hosts

44. Testing untestable code
External resources – Mock filesystem

45. Testing untestable code
External resources – Mock filesystem
<?php
// set up test environmemt
vfsStream::setup('exampleDir');
// create directory in test enviroment
mkdir(vfsStream::url('exampleDir').'/sample/');
// check if directory was created
echo vfsStreamWrapper::getRoot()­>hasChild('sample');

46. Testing untestable code
External resources – Mock Mailserver

47. Testing untestable code
External resources – Mock Mailserver
Use fake mail server

48. Testing untestable code
External resources – Mock Mailserver
$ cat /etc/php5/php.ini | grep sendmail_path
sendmail_path=/usr/local/bin/logmail
$ cat /usr/local/bin/logmail
cat >> /tmp/logmail.log

49. Testing untestable code
Dealing with language issues

50. Testing untestable code
Dealing with language issues
Testing your privates?

51. Testing untestable code
Dealing with language issues
<?php
class CustomWrapper {
private $_handler;
function stream_read($count) {
$content = fread($this­>_handler, $count);
$content = str_replace(
'private function',
'public function',
$content
);
return $content;
}
}

52. Testing untestable code
Dealing with language issues
$myClass = new MyClass();
$reflectionClass = new ReflectionClass('MyClass');
$reflectionMethod = $reflectionClass­>
getMethod('mydemo');
$reflectionMethod­>setAccessible(true);
$reflectionMethod­>invoke($myClass);

53. Testing untestable code
Dealing with language issues
Overwrite internal functions?

54. Testing untestable code
Dealing with language issues
pecl install runkit-0.9

55. Testing untestable code
Dealing with language issues - Runkit
<?php
ini_set('runkit.internal_override', '1');
runkit_function_redefine('mail','','return
true;');
?>

56. Testing untestable code
Dealing with language issues
pecl install funcall-0.3.0alpha

57. Testing untestable code
Dealing with language issues - Funcall
<?php
function my_func($arg1, $arg2) {
return $arg1.$arg2;
}
function post_cb($args,$result,
$process_time) {
// return custom result based on
$args
}
fc_add_post('my_func','post_cb');
var_dump(my_func('php', 'c'));

58. Testing untestable code
Dealing with language issues
funcall for methods?

59. Testing untestable code
Dealing with language issues
git clone https://github/juliens/AOP

60. Testing untestable code
Dealing with language issues - AOP
<?php
aop_add_after('Car::drive*',
'adviceForDrive');

61. Testing untestable code
Dealing with language issues - AOP
<?php
$advice = function(AopTriggeredJoinpoint
$jp) {
$returnValue =
$jp­>getReturnedValue();
// modify the return value
$returnValue = 1234;
$jp­>setReturnedValue($returnValue);
};
aop_add_after('Car­>drive()', $advice);

62. Testing untestable code
And now? Spaghetti mess...
<?php
$all_tables_query = ' SELECT table_name, MAX(version) as
version FROM ...';
$all_tables_result =
PMA_query_as_controluser($all_tables_query);
// If a HEAD version exists
if (PMA_DBI_num_rows($all_tables_result) > 0) {
?>
<div id="tracked_tables">
<h3><?php echo __('Tracked tables');?></h3>
<?php
}

65. Testing untestable code
What else?
Generative Programming

66. Testing untestable code
Generative Programming
Configuration
Configuration
(DSL)
(DSL)
1..n
Implementation-
Implementation-
components
Generator
Generator Product
components Product

67. Testing untestable code
Generative Programming
Configuration
Configuration
(DSL)
(DSL)
Customer 22
Customer
Implementation-
Implementation-
components
Generator
Generator Customer 11
components Customer

68. Testing untestable code
Generative Programming
Configuration
Configuration
(DSL)
(DSL)
Test
Test
Enviroment
Enviroment
Implementation-
Implementation-
components
Generator
Generator Prod.
Prod.
components Enviroment
Enviroment

69. Testing untestable code
Generative Programming
A frame is a data structure
for representing knowledge.

70. Testing untestable code
Frame
<?php
class Car {
private $Engine;
public function __construct($sEngine) {
$this­>Engine = <!{Factory}!>::
getByType($sEngine);
}
}

71. Testing untestable code
ContentProvider for the Frame
public class MyContentProvider extends
AbstractContentProvider {
public SlotConfiguration computeSlots(
FeatureConfiguration config) {
SlotConfiguration sl = new SlotConfiguration();
if(config.hasFeature("unittest")) {
sl.put("Factory", "FactoryMock");
} else {
sl.put("Factory", "EngineFactory");
}
return sl;
}
}

72. Testing untestable code
Generated result – Test Enviroment
<?php
class Car {
private $Engine;
public function __construct($sEngine) {
$this­>Engine = FactoryMock::
getByType($sEngine);
}
}

73. Testing untestable code
Generated result – Prod. Enviroment
<?php
class Car {
private $Engine;
public function __construct($sEngine) {
$this­>Engine = EngineFactory::
getByType($sEngine);
}
}

74. Testing untestable code
Curious for more?
http://replicatorframework.org

75. Thank you!

76. http://joind.in/7314

77. Testing untestable code
Flickr Credits
http://www.flickr.com/photos/andresrueda/3452940751/
http://www.flickr.com/photos/andresrueda/3455410635/