Help me write a PHPUnit Test for the following method - phpunit

Question

public function getAvailableVideosByRfid($rfid, $count=200) {
$query="SELECT id FROM sometable WHERE rfid='$rfid'";
$result = mysql_query($query);
$count2 = mysql_num_rows($result);
if ($count2){ //this rfid has been claimed
return 0;
}
My assertions are :
1). $rfid is a string 5 characters long
2). I am getting a valid result set
Thank You
Please assume that I have the following Unit Test code:
class videoSharingTest extends PHPUnit_Framework_TestCase {
/**
* #var videoSharing
*/
protected $object;
/**
* Sets up the fixture, for example, opens a network connection.
* This method is called before a test is executed.
*/
protected function setUp() {
$this->object = new videoSharing;
}
/**
* Tears down the fixture, for example, closes a network connection.
* This method is called after a test is executed.
*/
protected function tearDown() {
}
public function testGetAllVideosByRfid() {
******What should I put here*****
}

Answer 1

You need to decentralize your database, typically with a Database abstraction layer which you would mock out. Thus adding a ->setDatabase(), etc. on the object that has the method you are using. Then inside your setUp() { ... } you would set the Database object to a mock:
$this->object->setDatabase($mockDb);
Then you would change
$result = mysql_query($query);
$count2 = mysql_num_rows($result);
to use some form of PDO - so that you could call setDatabase() with a PDO Sql Lite. For example:
setUp() { $this->object->setDatabase($mockDb); }
testFunction() {
$rfid = 'the rfid to use in the test';
//make sure no videos exist yet
$this->assertEquals(0, count($this->object->getAvailableVideosByRfid($rfid, ..);
//you may want to assert that it returns a null/false/empty array/etc.
$db = $this->object->getDatabase();
$records = array(... some data ...);
$db->insert($records); //psuedo code
$vids = $this->object->getAvailableVideosByRfid($rfid, ..); //however you map
$this->assertEquals(count($records), count(vids));
foreach($vids as $video) {
//here you would map the $video to the corresponidng $record to make sure all
vital data was stored and retrieved from the method.
}
}
Typically this would all be done in PDO Sqlite so that no true database would be made/created just for the unit test & that it would live and die with the test, and any developer anywhere could use it with no configuration needed.