phpunit: mock object not fooling php

Question

I'm going through the zend tutorials and I am testing a class with a mock object with phpunit. When I pass a mock created from Zend\Db\TableGateway to my class, who's constructor expects a Zend\Db\TableGateway, I get an type error:

"...Argument 1 passed to Album\Model\AlbumTable::__construct() must be an instance of Zend\Db\TableGateway\TableGateway, instance of Mock_TableGateway_65b55cb0 given..."

Is this supposed happen? Are phpunit mock objects supposed to be able to "fool" the class?

Here is the real class:

class AlbumTable {
    protected $tableGateway;

    public function __construct(TableGateway $tableGateway) {
        $this->tableGateway = $tableGateway;
    }

    public function fetchAll() {
        $resultSet = $this->tableGateway->select();
        return $resultSet;
    }

    public function getAlbum($id){
        $id = (int) $id;
        $rowset = $this->tableGateway->select(array('id' => $id));
        $row = $rowset->current();
        if(!$row) {
            throw new \Exception("Couldn't find row: $id");
        }
        return $row;
    }

    public function saveAlbum(Album $album) {
        $data = array(
            'artist' => $album->artist,
            'title' => $album->title,
        );

        $id = (int)$album->id;
        if ($id == 0) {
            $this->tableGateway->insert($data);
        } else {
            if ($this->getAlbum($id)) {
                $this->tableGateway->update($data, array('id' => $id));
            } else {
                throw new \Exception('Form id does not exist');
            }
        }
    }

    public function deleteAlbum($id) {
        $this->tableGateway->delete(array('id' => $id));
    }

}

and the test:

class AlbumTableTest extends PHPUnit_Framework_TestCase {
    public function testFetchAllReturnsAllAlbums() {
        $resultSet = new ResultSet();
        $mockTableGateway = $this->getMock('Zend\Db\TableGateway',
            array('select'), array(), '', false);

        $mockTableGateway->expects($this->once())
            ->method('select')
            ->with()
            ->will($this->returnValue($resultSet));

        $albumTable = new AlbumTable($mockTableGateway);
        $this->assertSame($resultSet, $albumTable->fechAll());
    }
}

and the error:

Time: 102 ms, Memory: 5.00Mb

There was 1 error:

1) AlbumTest\Model\AlbumTableTest::testFetchAllReturnsAllAlbums
Argument 1 passed to Album\Model\AlbumTable::__construct() must be an instance of Zend\Db\TableGateway\TableGateway, instance of Mock_TableGateway_65b55cb0 given, called in C:\Users\MEEE\Google Drive\code\iis\www\CommunicationApp\module\Album\test\AlbumTest\Model\AlbumTableTest.php on line 20 and defined

C:\Users\MEEE\Google Drive\code\iis\www\CommunicationApp\module\Album\src\Album\Model\AlbumTable.php:9
C:\Users\MEEE\Google Drive\code\iis\www\CommunicationApp\module\Album\test\AlbumTest\Model\AlbumTableTest.php:20

FAILURES!
Tests: 4, Assertions: 9, Errors: 1.

Answer 1

You are not mocking the correct class. You are creating a mock of a Zend\Db\TableGateway and you need to actually mock Zend\Db\TableGateway\TableGateway

Change you test code to:

    $mockTableGateway = $this->getMock('Zend\Db\TableGateway\TableGateway',
        array('select'), array(), '', false);

Your mock was failing a type-hint because your not mocking the correct class.

Mock objects will extend the class that you are mocking, so they will be an instance of the class being mocked.