Unit Testing with PHPUnit

by Joeri Timmermans

What is Unit Testing?
Debunking the myths
Why do Unit Testing?
PHPUnit
Starting with PHPUnit
Basic assertions
Hello world!
Fixtures
Mock objects
Interesting reads
Questions?

//TODO:

What is Unit Testing?

Wikipedia:

"Unit testing is a software testing method by which individual units of source code are tested to determine if they are fit for use"

Debunking the myths

It Takes Too Long
There’s No Need to Test:
My Code Already Works!
Expensive
It’s No Fun

Automation
Readable code == Testable code
Test code on functionality
Reduce bugs in new and existing features
Reduce cost of changes
Easier refactoring
Progress indication of the project
Alerts generation for CI-tools
Forces you to slow down and think
Speed up development and reduce fear

Why do (Unit) Testing

PHPUnit

Created by Sebastian Bergmann
Part of xUnit Family
/sebastianbergmann/phpunit

Starting with PHPUnit

Download phar:
https://phpunit.de
Composer:
"phpunit/phpunit": "^8"
Setup phpunit.xml

phpunit.xml

<?xml version="1.0" encoding="UTF-8"?>

<phpunit
    backupGlobals               = "false" backupStaticAttributes      = "false"
    colors                      = "true" convertErrorsToExceptions   = "true"
    convertNoticesToExceptions  = "true" convertWarningsToExceptions = "true"
    processIsolation            = "false" stopOnFailure               = "false"
    syntaxCheck                 = "false" bootstrap                   = "bootstrap.php.cache" >

    <testsuites>
        <testsuite name="Project Test Suite">
            <directory>../src/*/*Bundle/Tests</directory>
            <directory>../src/*/Bundle/*Bundle/Tests</directory>
        </testsuite>
    </testsuites>

    <filter>
        <whitelist>
            <directory>../src</directory>
            <exclude>
                <directory>../src/*/*Bundle/Resources</directory>
                <directory>../src/*/*Bundle/Tests</directory>
                <directory>../src/*/Bundle/*Bundle/Resources</directory>
                <directory>../src/*/Bundle/*Bundle/Tests</directory>
            </exclude>
        </whitelist>
    </filter>
</phpunit>

Basic assertions

AssertTrue/AssertFalse - Check the input to verify it equals true/false
AssertEquals - Check the result against another input for a match
AssertGreaterThan - Check the result to see if it’s larger than a value
(there’s also LessThan, GreaterThanOrEqual, and LessThanOrEqual)
AssertContains - Check that the input contains a certain value
AssertType - Check that a variable is of a certain type
AssertNull - Check that a variable is null
AssertFileExists - Verify that a file exists
AssertRegExp - Check the input against a regular expression
...

Hello world!

<?php 

namespace Example;

class HelloWorld
{
	public $helloWorld;

	public function __construct($string = 'Hello World!')
	{
		$this->helloWorld = $string;
	}

	public function sayHello()
	{
		return $this->helloWorld;
	}
}

Our first test

<?php

namespace Example;

class HelloWorldTest extends \PHPUnit_Framework_TestCase
{

    public function testSayHello()
    {        
        $hw = new HelloWorld();
        $string = $hw->sayHello();
        $this->assertEquals('Hello World!', $string);
    }

}

The result!

PHPUnit 4.2.5 by Sebastian Bergmann.

Configuration read from /var/www/example/build/phpunit.xml

.

Time: 70 ms, Memory: 3.50Mb

OK (1 test, 1 assertion)

Fixtures

"Known state" of an application
- needs to be "set up" at start
- needs to be "torn down" at end
- shares "states" over test methods

<?php

namespace Example;

class MyListTest extends \PHPUnit_Framework_TestCase
{

    protected $myList;

    public function setUp()
    {
        $this->myList = array();
    }

    public function testMyListEmpty()
    {
        $this->assertEquals(0, sizeof($this->myList));
    }

    public function testMyListHasOne()
    {
        array_push($this->myList, 'myItem');
        $this->assertEquals(1, sizeof($this->myList));
    }

    public function tearDown()
    {
        unset($this->myList);
    }
    
}

The result!

PHPUnit 4.2.5 by Sebastian Bergmann.

Configuration read from /var/www/example/build/phpunit.xml

..

Time: 67 ms, Memory: 3.50Mb

OK (2 tests, 2 assertions)

Mock objects

Simulated objects
Mimics API or behaviour
In a controlled way
To test real objects

Mock objects

<?php 

namespace Example;

class HelloMailer
{
	public $mailer;

	public function __construct(Mailer $mailer)
	{
		$this->mailer = $mailer;
	}

	public function sendMessage($message)
	{
		return $this->mailer->send($message);
	}
}

<?php

namespace Example;

class HelloMailerTest extends \PHPUnit_Framework_TestCase
{
    protected $mailer;

    public function setUp()
    {
        $mailer = $this->getMockBuilder('Example\Mailer')
                           ->setMockClassName('Mailer')
                           ->disableOriginalConstructor()
                           ->setMethods(array('send'))
                           ->getMock();

        $mailer->expects($this->any())
                   ->method('send')
                   ->with($this->equalTo('Hello mailer!'))
                   ->will($this->returnValue(true));

        $this->mailer = $mailer;
    }

    public function testSend()
    {   
        $hm = new HelloMailer($this->mailer);

        $response = $hm->sendMessage('Hello mailer!');
        $this->assertTrue($response);
    }

}

The result!

PHPUnit 4.2.5 by Sebastian Bergmann.

Configuration read from /var/www/example/build/phpunit.xml

.

Time: 80 ms, Memory: 4.00Mb

OK (1 test, 1 assertion)

Interesting reads

https://phpunit.de/
http://www.dragonbe.com/
http://www.sitepoint.com/tutorial-introduction-to-unit-testing-in-php-with-phpunit/

Questions?

Thank you

@Joeri_timmer
/pix-art
www.pix-art.be