Mocking Iterator using PHPUnit

<?php

include_once dirname(__FILE__) . '/../lib/exampleList.php';

/**
 * Tests for _mock_ Iterator
 *
 * Here we are mocking the iterator and making it work. We would want to do
 * this where we were testing some other class that contained an Iterator
 * dependency.
 *
 * @author Dave Gardner <dave@davegardner.me.uk>
 */
class mockedIteratorTest extends PHPUnit_Framework_TestCase
{
    private function buildSystemUnderTest()
    {
        return $this->getMock('exampleList');
    }

    public function testConstructs()
    {
        $list = $this->buildSystemUnderTest();
        $this->assertInstanceOf('exampleList', $list);
        $this->assertInstanceOf('Iterator', $list);
    }

    public function testHasZeroItemsWhenWeHaventMockedMethods()
    {
        $list = $this->buildSystemUnderTest();
        $counter = 0;
        foreach ($list as $item)
        {
            $counter++;
        }
        $this->assertEquals(0, $counter);
    }

    public function testWhenMockOneIterationWithNoKey()
    {
        $list = $this->buildSystemUnderTest();

        $list->expects($this->at(0))
             ->method('rewind');
        $list->expects($this->at(1))
             ->method('valid')
             ->will($this->returnValue(TRUE));
        $list->expects($this->at(2))
             ->method('current')
             ->will($this->returnValue('This is the first item'));
        $list->expects($this->at(3))
             ->method('next');
        $list->expects($this->at(4))
             ->method('valid')
             ->will($this->returnValue(FALSE));

        $counter = 0;
        foreach ($list as $value)
        {
            $counter++;
        }
        $this->assertEquals(1, $counter);
        $this->assertEquals('This is the first item', $value);
    }

    public function testWhenMockOneIterationWithKey()
    {
        $list = $this->buildSystemUnderTest();

        $list->expects($this->at(0))
             ->method('rewind');
        $list->expects($this->at(1))
             ->method('valid')
             ->will($this->returnValue(TRUE));
        $list->expects($this->at(2))
             ->method('current')
             ->will($this->returnValue('This is the first item'));
        $list->expects($this->at(3))
             ->method('key')
             ->will($this->returnValue('key1'));
        $list->expects($this->at(4))
             ->method('next');
        $list->expects($this->at(5))
             ->method('valid')
             ->will($this->returnValue(FALSE));

        $counter = 0;
        foreach ($list as $key => $value)
        {
            $counter++;
        }
        $this->assertEquals(1, $counter);
        $this->assertEquals('key1', $key);
        $this->assertEquals('This is the first item', $value);
    }

    public function testWhenMockThreeIterationWithNoKey()
    {
        $list = $this->buildSystemUnderTest();

        $list->expects($this->at(0))
             ->method('rewind');

        // iteration 1
        $list->expects($this->at(1))
             ->method('valid')
             ->will($this->returnValue(TRUE));
        $list->expects($this->at(2))
             ->method('current')
             ->will($this->returnValue('This is the first item'));
        $list->expects($this->at(3))
             ->method('next');

        // iteration 2
        $list->expects($this->at(4))
             ->method('valid')
             ->will($this->returnValue(TRUE));
        $list->expects($this->at(5))
             ->method('current')
             ->will($this->returnValue('This is the second item'));
        $list->expects($this->at(6))
             ->method('next');

        // iteration 2
        $list->expects($this->at(7))
             ->method('valid')
             ->will($this->returnValue(TRUE));
        $list->expects($this->at(8))
             ->method('current')
             ->will($this->returnValue('And the final item'));
        $list->expects($this->at(9))
             ->method('next');

        $list->expects($this->at(10))
             ->method('valid')
             ->will($this->returnValue(FALSE));

        $counter = 0;
        $values = array();
        foreach ($list as $value)
        {
            $values[] = $value;
            $counter++;
        }
        $this->assertEquals(3, $counter);

        $expectedValues = array(
            'This is the first item',
            'This is the second item',
            'And the final item'
        );
        $this->assertEquals($expectedValues, $values);
    }
}