This document provides an introduction to test-driven development (TDD) and unit testing in PHP. It discusses where to start with TDD, what unit tests are, and tools to use like PHPUnit. It covers the red-green-refactor TDD cycle and topics like mocking dependencies, handling file systems and databases in tests, and continuous integration. The goal is to help PHP developers get started with TDD.

1. Getting Started With TDD
Eric Hogue - @ehogue
Confoo - 2014-02-27

2. TDD

3. Where should I
Start?

4. 1. Unit tests
2. Test Driven Development
3. What’s next?

5. Unit Tests

6. Unit Test
a method by which individual units of source
code [...] are tested to determine if they are fit
for use
http://en.wikipedia.org/wiki/Unit_testing

7. Don’t Cross boundaries

8. Tools
●
●
●
●
SimpleTest
atoum
PHPT
PHPUnit

10. Installation - Phar
$ wget
https://phar.phpunit.de/phpunit.phar
$ chmod +x phpunit.phar
$ mv phpunit.phar /usr/local/bin/phpunit

11. Installation - Pear
pear config-set auto_discover 1
pear install pear.phpunit.de/PHPUnit

12. Installation - Composer
# composer.json
{
"require-dev": {
"phpunit/phpunit": "3.7.*"
}
}
$ composer install

13. PHPUnit
FactorialTest.php
<?php
class FactorialTest extends
PHPUnit_Framework_TestCase {
}

14. public function testSomething() {
}
/** @test */
public function somethingElse() {
}

15. ● Arrange
● Act
● Assert

16. Arrange
/** @test */
public function factOf1() {
$factorial = new Factorial;
}

17. Act
/** @test */
public function factOf1() {
$factorial = new Factorial;
$result = $factorial->fact(1);
}

18. Assert
/** @test */
public function factOf1() {
$factorial = new Factorial;
$result = $factorial->fact(1);
$this->assertSame(1, $result);
}

19. PHPUnit Assertions
●
●
●
●
●
●
●
$this->assertTrue();
$this->assertEquals();
$this->assertSame();
$this->assertContains();
$this->assertNull();
$this->assertRegExp();
...

20. Preparing For Your Tests
setup() -> Before every tests
teardown() -> After every tests
setUpBeforeClass() + tearDownAfterClass()
Once per test case

21. phpunit.xml
<phpunit bootstrap="bootstrap.php"
colors="true"
strict="true"
verbose="true"
>
...
</phpunit>

22. phpunit.xml
<phpunit>
<testsuites>
<testsuite name="My Test Suite">
<directory>path</directory>
<file>path</file>
<exclude>path</exclude>
</testsuite>
</testsuites>
</phpunit>

24. TDD

25. Red - Green - Refactor
Red
Write a failing test

26. Red - Green - Refactor
Green
Make it pass

27. Red - Green - Refactor
Refactor
Fix any shortcuts you took

28. /** @test */
public function create() {
$this->assertNotNull(new Factorial);
}

29. class Factorial {
}

30. /** @test */
public function factOf1() {
$facto = new Factorial;
$this->assertSame(1,
$facto->fact(1));
}

31. public function fact($number) {
return 1;
}

32. Duplication
public function create() {
$this->assertNotNull(new Factorial);
}
public function factOf1() {
$facto = new Factorial;
...

33. public function setup() {
$this->facto = new Factorial;
}
/** @test */
public function factOf1() {
$this->assertSame(1,
$this->facto->fact(1));
}

34. /** @test */
public function factOf2() {
$this->assertSame(2,
$this->facto->fact(2));
}

35. public function fact($number) {
return $number;
}

36. More duplication
/** @test */
public function factOf1() {
$this->assertSame(1,
$this->facto->fact(1));
}
/** @test */
public function factOf2() {
$this->assertSame(2,
$this->facto->fact(2));
}

37. public function factDataProvider() {
return array(
array(1, 1),
array(2, 2),
);
}

38. /**
* @test
* @dataProvider factDataProvider
*/
public function factorial($number,
$expected) {
...

39. …
$result =
$this->facto->fact($number);
$this->assertSame($expected,
$result);
}

40. public function factDataProvider() {
…
array(2, 2),
array(3, 6),
...

41. public function fact($number) {
if ($number < 2) return 1;
return $number *
$this->fact($number - 1);
}

42. It’s a lot of
work

44. Dependencies

45. Problems
class Foo {
public function __construct() {
$this->bar = new Bar;
}
}

46. Dependency Injection

47. Setter Injection
class Foo {
public function setBar(Bar $bar) {
$this->bar = $bar;
}
public function doSomething() {
// Use $this->bar
}
}

48. Constructor Injection
class Foo {
public function __construct(
Bar $bar) {
$this->bar = $bar;
}
public function doSomething() {
// Use $this->bar
}
}

49. Pass the dependency directly
class Foo {
public function doSomething(
Bar $bar) {
// Use $bar
}
}

50. File System

51. vfsStream
Virtual Files System
composer.json
"require-dev": {
"mikey179/vfsStream": "*"
},

52. Check if a folder was created
$root = vfsStream::setup('dir');
$parentDir = $root->url('dir');
//Code creating sub folder
$SUT->createDir($parentDir, 'test');
$this->assertTrue(
$root->hasChild('test'));

53. Reading a file
$struct = array(
'subDir' => array('test.txt'
=> 'content')
);
$root = vfsStream::setup('root',
null, $struct);
$parentDir = $root->url('root');
...

54. Reading a file
…
$content = file_get_contents(
$parentDir . '/subDir/test.txt');
$this->assertSame('content',
$content);

55. Databases

56. Mocks
Replaces a dependency
● PHPUnit mocks
● Mockery
● Phake

57. Creation
$mock = $this->getMock('NSClass');

58. Creation
$mock = $this->getMock('NSClass');
Or
$mock = $this->getMockBuilder
('NamespaceClass')
->disableOriginalConstructor()
->getMock();

59. $mock->expects($this->once())
->method('methodName')

60. $mock->expects($this->once())
->method('methodName')
->with(1, 'aa', $this->anything())

61. $mock->expects($this->once())
->method('methodName')
->with(1, 'aa', $this->anything())
->will($this->returnValue(10));

62. Mocking PDO
$statement = $this->getMockBuilder
('PDOStatement')
->getMock();
$statement->expects($this->once())
->method('execute')
->will($this->returnValue(true));
...

63. ...
$statement->expects($this->once())
->method('fetchAll')
->will(
$this->returnValue(
array(array('id' => 123))
)
);
...

64. $this->getMockBuilder('PDO')
->getMock();

65. …
$pdo = $this->getMockBuilder(
'stdClass')
->setMethods(array('prepare'))
->getMock();
$pdo->expects($this->once())
->method('prepare')
->will(
$this->returnValue($statement));

66. class PDOMock extends PDO {
public function __construct() {}
}
$pdo = $this->getMockBuilder
('PDOMock')
->getMock();

67. mysql_*

68. DbUnit Extension
extends
PHPUnit_Extensions_Database_TestCase
public function getConnection() {
$pdo = new PDO('sqlite::memory:');
return $this->
createDefaultDBConnection(
$pdo, ':memory:');
}

69. public function getDataSet() {
return $this->
createFlatXMLDataSet('file');
}

70. API

71. ● Wrap all call into a class
○ ZendHttp
○ Guzzle
○ Simple class that uses curl
● Mock the class
○ Return the wanted xml/json

72. Pros and Cons

73. Pros
● Less regressions

74. Pros
● Less regressions
● Trust

75. Pros
● Less regressions
● Trust
● Low coupling

76. Pros
●
●
●
●
Less regressions
Trust
Low coupling
Simple Design

77. Cons
● Takes longer

78. “If it doesn't have to
work, I can get it done a
lot faster!”
- Kent Beck

79. Cons
● Takes longer
● Can be hard to sell to managers

80. Cons
● Takes longer
● Can be hard to sell to managers
● It’s hard

81. Prochaines étapes?

82. Continuous Testing - Guard

83. Continuous Integration

84. Continuous Integration
● Run your tests automatically
○
○
○
○
Unit Tests
Acceptance Tests
Performance Tests
...

85. Continuous Integration
● Run your tests automatically
○
○
○
○
Unit Tests
Acceptance Tests
Performance Tests
…
● Check Standards
○ phpcs

86. Continuous Integration
● Run your tests automatically
○
○
○
○
Unit Tests
Acceptance Tests
Performance Tests
…
● Check Standards
○ phpcs
● Check for "code smells"
○ phpcpd
○ PHP Depend
○ PHP Mess Detector

87. Questions
Twitter:
@ehogue
Blog:
http://erichogue.ca/
Slides: http://www.
slideshare.net/EricHogue

88. Credits
●
●
●
●
●
●
●
●
●
●
●
●
●
●
●
Paul - http://www.flickr.com/photos/pauldc/4626637600/in/photostream/
JaseMan - http://www.flickr.com/photos/bargas/3695903512/
mt 23 - http://www.flickr.com/photos/32961941@N03/3166085824/
Adam Melancon - http://www.flickr.com/photos/melancon/348974082/
Zhent_ - http://www.flickr.com/photos/zhent/574472488/in/faves-96579472@N07/
Ryan Vettese - http://www.flickr.com/photos/rvettese/383453435/
shindoverse - http://www.flickr.com/photos/shindotv/3835363999/
Eliot Phillips - http://www.flickr.com/photos/hackaday/5553713944/
World Bank Photo Collection - http://www.flickr.com/photos/worldbank/8262750458/
Steven Depolo - http://www.flickr.com/photos/stevendepolo/3021193208/
Deborah Austin - http://www.flickr.com/photos/littledebbie11/4687828358/
tec_estromberg - http://www.flickr.com/photos/92334668@N07/11122773785/
nyuhuhuu - http://www.flickr.com/photos/nyuhuhuu/4442144329/
Damián Navas - http://www.flickr.com/photos/wingedwolf/5471047557/
Improve It - http://www.flickr.com/photos/improveit/1573943815/