PHPUnit Pocket Guide

Chapter 3. PHPUnit's Goals

So far, we only have two tests for the Array built-in and the sizeof( ) function. When we start to test the numerous array_*( ) functions PHP offers, we will need to write a test for each of them. We could write all these tests from scratch. However, it is much better to write a testing infrastructure once and then write only the unique parts of each test. PHPUnit is such an infrastructure.

Example 5 shows how we have to rewrite our two tests from Example 4 so that we can use them with PHPUnit.

Example 5. Testing Array and sizeof( ) with PHPUnit

<?php
require_once 'PHPUnit2/Framework/TestCase.php';

class ArrayTest extends PHPUnit2_Framework_TestCase {
  public function testNewArrayIsEmpty( ) {
    // Create the Array fixture.
    $fixture = Array( );

    // Assert that the size of the Array fixture is 0. 
    $this->assertEquals(0, sizeof($fixture)); 
  }
  public function testArrayContainsAnElement( ) { 
    // Create the Array fixture.    
		$fixture = Array( );

    // Add an element to the Array fixture.    
		$fixture[] = 'Element';
 
		// Assert that the size of the Array fixture is 1. 
		$this->assertEquals(1, sizeof($fixture));
  }
}
?>

Example 5 shows the basic steps for writing tests with PHPUnit:

1. The tests for a class Class go into a class ClassTest.

2. ClassTest inherits (most of the time) from PHPUnit2_ Framework_TestCase.

3. The tests are public methods that expect no parameters and are named test*.

4. Inside the test methods, assertion methods such as assertEquals( ) (see Table 6) are used to assert that ...