The document discusses different techniques for unit testing such as using mock objects, fixtures, stubs, and dependency injection to isolate parts of a program and test them independently; it also covers concepts like test-driven development and regression testing to prevent bugs from being reintroduced with code changes. The overall message is that writing unit tests leads to better architecture and helps improve code quality.

1. Unit Test Fun: Mock Objects, Fixtures,
Stubs & Dependency Injection
Max Köhler I 02. Dezember 2010
© 2010 Mayflower GmbH

2. Wer macht UnitTests?
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3. Code Coverage?
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4. Wer glaubt, dass die Tests
gut sind?
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5. Kann die Qualität
gesteigert werden?
100%
0%
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6. Test der kompletten
Architektur?
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7. MVC?
Controller
View Model
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8. Wie testet Ihr eure
Models?
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9. Direkter DB-Zugriff?
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10. Keine UnitTests!
STOP
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11. Integration Tests!
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12. Wie testet Ihr eure
Controller?
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13. Routes, Auth-Mock,
Session-Mock, ...?
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14. Keine UnitTests!
STOP
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15. Was wollen wir testen?
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16. Integration Regression
Testing Testing
Unit Testing
System - Integration
Testing
Acceptance
Testing
System Testing
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17. The goal of unit testing is
to isolate each part of the
program and show that
the individual parts are
correct
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18. Test Doubles
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19. Stubs
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20. Fake that returns
canned data...
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21. Beispiel für ein Auth-Stub
$storageData = array(
'accountId' => 29,
'username' => 'Hugo',
'jid' => 'hugo@example.org');
$storage = $this->getMock('Zend_Auth_Storage_Session', array('read'));
$storage->expects($this->any())
->method('read')
->will($this->returnValue($storageData));
Zend_Auth::getInstance()->setStorage($storage);
// ...
/*
* Bei jedem Aufruf wird nun das Mock als Storage
* verwendet und dessen Daten ausgelesen
*/
$session = Zend_Auth::getInstance()->getIdentity();
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22. Mocks
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23. Spy with
expectations...
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24. Model Mapper Beispiel
class Application_Model_GuestbookMapper
{
protected $_dbTable;
public function setDbTable(Zend_Db_Table_Abstract $dbTable)
{
$this->_dbTable = $dbTable;
return $this;
}
public function getDbTable()
{
return $this->_dbTable;
}
public function getEmail() {}
public function getComment() {}
public function save(Application_Model_Guestbook $guestbook)
{
$data = array(
'email' => $guestbook->getEmail(),
'comment' => $guestbook->getComment(),
);
$this->getDbTable()->insert($data);
}
}
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25. Testen der save() Funktion
class Applicatoin_Model_GuestbookMapperTest extends PHPUnit_Framework_TestCase
{
public function testSave()
{
$modelStub = $this->getMock('Application_Model_Guestbook', array('getEmail', ,getComment'));
$modelStub->expects($this->once())
->method('getEmail')
->will($this->returnValue('super@email.de'));
$modelStub->expects($this->once())
->method('getComment')
->will($this->returnValue('super comment'));
$tableMock = $this->getMock('Zend_Db_Table_Abstract', array('insert'), array(), '', false);
$tableMock->expects($this->once())
->method('insert')
->with($this->equalTo(array(
'email' => 'super@email.de',
'comment' => 'super comment')));
$model = new Application_Model_GuestbookMapper();
$model->setDbTable($tableMock); // << MOCK
$model->save($modelStub); // << STUB
}
}
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26. Stub Mock
Fake that Spy with
returns canned !== expectations...
data...
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27. Fixtures
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28. Set the world up
in a known
state ...
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29. Fixture-Beispiel
class Fixture extends PHPUnit_Framework_TestCase
{
protected $fixture;
protected function setUp()
{
$this->fixture = array();
}
public function testEmpty()
{
$this->assertTrue(empty($this->fixture));
}
public function testPush()
{
array_push($this->fixture, 'foo');
$this->assertEquals('foo', $this->fixture[0]);
}
public function testPop()
{
array_push($this->fixture, 'foo');
$this->assertEquals('foo', array_pop($this->fixture));
$this->assertTrue(empty($this->fixture));
}
}
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30. Method Stack
Ablauf
public static function setUpBeforeClass() { }
protected function setUp() { }
public function testMyTest() { /* TEST */ }
protected function tearDown() { }
protected function onNotSuccessfulTest(Exception $e) { }
public static function tearDownAfterClass() { }
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31. Test Suite ...
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32. ...wirkt sich auf die
Architektur aus.
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33. Wenn nicht...
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34. Developer
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35. Was kann man machen?
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36. Production Code
überarbeiten
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37. Dependency Injection
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38. Bemerkt?
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39. Dependency Injection
class Application_Model_GuestbookMapper
{
protected $_dbTable;
public function setDbTable(Zend_Db_Table_Abstract $dbTable)
{
$this->_dbTable = $dbTable;
return $this;
}
public function getDbTable()
{
return $this->_dbTable;
}
public function getEmail() {}
public function getComment() {}
public function save(Application_Model_Guestbook $guestbook)
{
$data = array(
'email' => $guestbook->getEmail(),
'comment' => $guestbook->getComment(),
);
$this->getDbTable()->insert($data);
}
}
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40. Besser aber ...
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41. ... Begeisterung sieht anders aus!
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42. Was könnte noch helfen?
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43. TDD?
Test Driven Development
[
~~
[ ~~
~~ ~~
~~ ~~
~~ ~~
~
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44. Probleme früh erkennen!
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45. Uncle Bob´s
Three Rules of TDD
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46. #1
“ You are not allowed to write any
production code unless it is to make a
failing unit test pass.
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47. #2
“ You are not allowed to write any more of
a unit test than is sufficient to fail; and
compilation failures are failures.
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48. #3
“ You are not allowed to write any more
production code than is sufficient to pass
the one failing unit test.
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49. Und wieder...
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50. Developer
Titel der Präsentation I Mayflower GmbH I xx. Juni 2010 I 50

51. Und jetzt?
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52. Things get worst
before they get
better !
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53. Monate später...
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54. Gibts noch was?
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55. Darf ich vorstellen:
„Bug“
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56. Regression Testing
or
Test your Bugs!
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57. Regression Testing
Bug
class Calculate
{
public function divide($dividend, $divisor)
1 {
return $dividend / $divisor;
}
}
2 Warning: Division by zero in /srv/phpunit-slides/Calculate.php on line 7
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58. Regression Testing
Test First!
/**
* Regression-Test BUG-123
*
* @group BUG-123
*
* @return void
3 */
public function testDivideByZero()
{
$calc = new Calculate();
$this->assertEquals(0, $calc->divide(1, 0));
}
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59. Regression Testing
Bugfix
class Calculate
{
4 public function divide($dividend, $divisor)
{
if (0 == $divisor) {
return 0;
}
return $dividend / $divisor;
}
}
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60. Regression Testing
phpunit
slides$ phpunit --colors --verbose CalculateTest.php
PHPUnit 3.5.5 by Sebastian Bergmann.
5
CalculateTest
......
Time: 0 seconds, Memory: 5.25Mb
OK (6 tests, 6 assertions)
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61. Regression Testing
@group
slides$ phpunit --colors --verbose --group BUG-123 CalculateTest.php
PHPUnit 3.5.5 by Sebastian Bergmann.
?
CalculateTest
.
Time: 0 seconds, Memory: 5.25Mb
OK (1 tests, 1 assertions)
/**
* Regression-Test BUG-123
*
* @group BUG-123
*
* @return void
? */
public function testDivideByZero()
{
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62. Noch Fragen?
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63. Quellen
I Baby: ADDROX http://www.flickr.com/photos/addrox/2587484034/sizes/m/
I Fish: ADDROX http://www.flickr.com/photos/addrox/274632284/sizes/m/
I Happy: ADDROX http://www.flickr.com/photos/addrox/2610064689/sizes/m/
I Bug: ADDROX http://www.flickr.com/photos/addrox/284649644/sizes/m/
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64. Vielen Dank für Ihre Aufmerksamkeit!
Kontakt Max Köhler
max.koehler@mayflower.de
+49 89 242054-1160
Mayflower GmbH
Mannhardtstr. 6
80538 München
© 2010 Mayflower GmbH