Building Testable PHP Applications Chris Hartjes MidwestPHP 2013 - Mar. 3, 2013 @grmpyprogrammer

Text Story Time

WHY DO WE TEST? Because programming is hard

WHY DO WE TEST?

A HUGE TOPIC

UNCOMFORTABLE TRUTHS Some of this will not make sense to you

UNCOMFORTABLE TRUTHS Some applications will resist all attempts to test

UNCOMFORTABLE TRUTHS Testing is good Testable applications are better

SO WHAT CAN WE DO?

IT’S ABOUT TOOLS

IT’S ABOUT STRATEGIES

AUTOMATION IS KEY

AUTOMATION IS KEY “Write a script that will run all your tests before you go live”

AUTOMATION “Tell your version control system to run your tests on commit or push”

AUTOMATION IS KEY http://jenkins-ci.org http://travis-ci.org

ARCHITECTURE “Simple systems can display complex behavior but complex systems can only display simple behaviour”

ARCHITECTURE “Inside every great large application are many great small applications”

ARCHITECTURE “Your framework is a detail, not the core of your application.” -- Bob Martin

LAW OF DEMETER “The Law of Demeter for functions states that any method of an object should call only methods belonging to itself, any parameters that were passed in to the method, any objects it created, and any directly held component objects. ”

DEPENDENCY INJECTION “Pass objects and their methods other objects and function that are required for the task.”

DEPENDENCY INJECTION getUri()] >= $_SESSION['user_level']); } } // Meanwhile inside your controller $acl = new \Grumpy\Acl(); if (!$acl->accessAllowed()) { \Grumpy\View::render('access_denied.tmpl'); } else { \Grumpy\View::render('show_stolen_cc.tmpl'); }

DEPENDENCY INJECTION _request = $request; ! ! $this->_userLevel = $userLevel; ! } } // Meanwhile inside your controller $acl = new \Grumpy\Acl($this->request, $_SESSION['user_level']); if (!$acl->accessAllowed()) { ! \Grumpy\View::render('access_denied.tmpl'); } else { ! \Grumpy\View::render('show_stolen_cc.tmpl'); }

DEPENDENCY INJECTION _request = $value; ! } ! public function setUserLevel($value) ! { ! ! $this->_userLevel = $value; ! } } // Meanwhile inside your controller... $acl = new \Grumpy\Acl(); $acl->setRequest($this->_request); $acl->setUserLevel($_SESSION['user_level']); if (!$acl->accessAllowed()) { ! \Grumpy\View::render('access_denied.tmpl'); } else { ! \Grumpy\View::render('show_stolen_cc.tmpl'); }

MOCK OBJECTS “Mock objects allow you to test code in proper isolation”

MOCK OBJECTS Database connections Web services File system operations

HOW DO WE TEST THIS? _request = $request; ! ! $this->_userLevel = $userLevel; ! } } // Meanwhile inside your controller $acl = new \Grumpy\Acl($this->request, $_SESSION['user_level']); if (!$acl->accessAllowed()) { ! \Grumpy\View::render('access_denied.tmpl'); } else { ! \Grumpy\View::render('show_stolen_cc.tmpl'); }

HOW DO WE TEST THIS? getMockBuilder('\Grumpy\Controller\Request') ! ! ! ->disableOriginalConstructor() ! ! ! ->getMock(); ! ! $mockController->expects($this->once)) ! ! ! ->method('getUri') ! ! ! ->will($this->returnValue('/account/purge')); ! ! $testUserLevel = 'admin'; ! ! $acl = new \Grumpy\Acl($mockRequest, $testUserLevel); ! ! $this->assertTrue( ! ! ! $acl->accessAllowed(), ! ! ! 'admin user should have access to purge accounts' ! ! ); ! } }

HOW DO WE TEST THIS? “Protected and private methods and attributes are difficult to test properly”

METHODS? Etsy’s PHPUnit Extensions https:/ /github.com/etsy/phpunit-extensions Uses annotations to flag methods you wish to test

METHODS? class ObjectWithPrivate { ! private function myInaccessiblePrivateMethod() ! { ! ! return 'inaccessible'; ! } ! /** @accessibleForTesting */ ! private function myAccessiblePrivateMethod() { ! ! return 'accessible'; ! } }

METHODS? class ObjectWithPrivateTest extends PHPUnit_Framework_Testcase { ! public $accessible; ! public function setUp() ! { ! ! parent::setUp(); ! ! $this->accessible = new PHPUnit_Extensions_Helper_AccessibleObject( ! ! ! new ObjectWithPrivate()); ! } ! public function testMyAccessiblePrivateMethod() ! { ! ! $this->assertEquals( ! ! ! 'accessible', ! ! ! $this->accessible->myAccessiblePrivateMethod() ! ! ); ! } }

METHODS? PHP’S Reflection API http:/ /www.gpug.ca/2012/06/02/testing- protected-methods-with-phpunit/

METHODS? class Foo { ! protected $_message; ! protected function _bar() ! { ! ! $this->_message = 'WRITE TESTS OR I CUT YOU'; ! } }

METHODS? class FooTest extends PHPUnit_Framework_Testcase() { ! public function testProtectedBar() ! { ! ! $testFoo = new Foo(); ! ! $expectedMessage = 'WRITE TESTS OR I CUT YOU'; ! ! $reflectedFoo = new \ReflectionMethod($testFoo, '_bar'); ! ! $reflectedFoo->setAccessible(true); ! ! $reflectedFoo->invoke($testFoo); ! ! $testMessage = \PHPUnit_Framework_Assert::readAttribute( ! ! ! $testFoo, ! ! ! '_message') ! ! $this->assertEquals( ! ! ! $expectedMessage, ! ! ! $testMessage, ! ! ! "Did not get expected message" ! ! ); ! } }

ATTRIBUTES? PHP’S Reflection API PHPUnit lets you check attribute values but not set them

HOW DO YOU TEST THIS? “If your unit test actually uses the database, you are doing it wrong”

HOW DO YOU TEST THIS? class Bar { ! public function getBazById($id) ! { ! ! $this->db->query("SELECT * FROM baz WHERE id = :bazId"); ! ! $this->db->bind('bazId', $id); ! ! $results = $this->db->execute(); ! ! $bazList = array(); ! ! if (count($results) > 0) { ! ! ! foreach ($results as $result) { ! ! ! ! $bazList[] = $result; ! ! ! } ! ! } ! ! return $bazList; ! } }

HOW DO YOU TEST THIS? class BarTest extends PHPUnit_Framework_Testcase { ! public function testGetBazById() ! { ! ! $bazId = 666; ! ! $expectedResults= array(1, 2, 3, 4, 5); ! ! $mockDb = $this->getMockBuilder('\Grumpy\Db') ! ! ! ->disableOriginalConstructor() ! ! ! ->setMethods(array('query', 'execute', 'bind')) ! ! ! ->getMock(); ! ! $mockDb->expects($this->once()) ! ! ! ->method('query'); ! ! $mockDb->expects($this->once()) ! ! ! ->method('bind'); ! ! $mockDb->expects($this->once()) ! ! ! ->method('execute') ! ! ! ->will($this->returnValue($testResults)); ! ! $testBar = new Bar(); ! ! $testBar->setDb($mockDb); ! ! $testResults = $testBar->getBazById($bazId); ! ! $this->assertEquals( ! ! ! $expectedResults, ! ! ! $testResults, ! ! ! 'Did not get expected baz result set' ! ! ); ! } }

HOW DO YOU TEST THIS? “API calls should be done via wrapper methods”

HOW DO YOU TEST THIS? _call('/api/bands', $this->_apiKey); ! } } class HipsterApiWrapper { ! public function __construct($hipsterApi) ! { ! ! $this->_hipsterApi = $hipsterApi; ! } ! public function getBands() ! { ! ! return $this->_hipsterApi->getBands(); ! } }

HOW DO WE TEST THIS? class HipsterApiTest extends PHPUnit_Framework_Testcase { ! public function testGetBands() ! { ! ! $hipsterApiData = "[{'id': 17, 'Anonymous'}, {'id': 93, 'HipStaar'}]"; ! ! $mockHipsterApi = $this->getMockBuilder('HipsterApi') ! ! ! ->disableOriginalConstructor() ! ! ! ->getMock(); ! ! $mockHipsterApi->expects($this->once()) ! ! ! ->with('getBands') ! ! ! ->will($this->returnValue($hipsterApiData)); ! ! $expectedData = json_decode($hipsterApiData); ! ! $hipsterApiWrapper = new HipsterApiWrapper($mockHipsterApi); ! ! $testData = $hipsterApiWrapper->getBands(); ! ! ! ! ! $this->assertEquals( ! ! ! $expectedData, ! ! ! $testData, ! ! ! 'Did not get expected getBands() result from HipsterApi' ! ! ); ! } }

ENVIRONMENTS “Your app shouldn’t care what environment it runs in.”

ENVIRONMENTS “Keep config files for each environment under version control” https:/ /github.com/flogic/ whiskey_disk

WHAT NOT TO DO

WHAT NOT TO DO “Avoid the use of static method calls”

WHAT NOT TO DO

WHAT NOT TO DO 1. Get a Dependency Injection Container 2. Create a fake version of your object with the static call 3. use the container inside the test

WHAT NOT TO DO “Avoid creating new non-core objects unless it’s a factory”

WHAT NOT TO DO toPdf($name); } }

WHAT NOT TO DO 1. Learn dependency injection 2. Create version of your object 3. Inject the dependency

WHAT NOT TO DO “Be careful with chaining methods”

WHAT NOT TO DO what() ->is() ->this() ->i() ->dont() ->even(); } }

WHAT NOT TO DO 1. Reduce the number of chains 2. Reduce the amount of work

RESOURCES The Grumpy Programmer’s Guide to Building Testable PHP Applications http:/ /grumpy-testing.com

RESOURCES The Grumpy Programmer’s PHPUnit Cookbook http:/ /grumpy-phpunit.com

RESOURCES The people sitting next to you

THANK YOU! @grmpyprogrammer http:/ /www.littlehart.net/atthekeyboard https:/ /joind.in/8233