Mocking a REST Datasource in a Model TestCase for CakePHP - web-services

Question

I am using the CakePHP-ReST-DataSource-Plugin Datasource for hitting a RESTful service in my model. This implies that the models will not have a database connection.
I have successfully accessed the services and would now like to write unit tests for the models. This is proving to be a daunting task since I cannot succeed to mock the datasource so that I do not hit the actual remote Service but rather return expected results for the tests.
<?php
App::uses('KnowledgePoint', 'Model');
class KnowledgePointTest extends CakeTestCase{
public $fixtures = array('app.knowledgepoint');
public $useDbConfig = 'RestTest';
private $KnowledgePoint;
public function setUp() {
parent::setUp();
$this->KnowledgePoint = ClassRegistry::init('KnowledgePoint');
/**
* This is the confusing part. How would I mock the datasource
so that I can mock the request method which returns the data
from the api?
*/
$this->KnowledgePoint->DataSource = $this->getMockForModel(
'RestSource',array('request'));
}
public function tearDown() {
parent::tearDown();
}
}
I would like to be able to mock the datasource and stub the request method to return data that would normally be returned from the remote service.
Kind regards,
Roland

Answer 1

Mocking the model and its getDataSource() method so that it returns your mocked datasource should theoretically work. Here's an example
App::uses('RestSource', 'Rest.Model/Datasource');
$DataSource = $this->getMock('RestSource', array('request'), array(array()));
$DataSource
->expects($this->any())
->method('request')
->will($this->returnValue('some custom return value'));
$Model = $this->getMockForModel('KnowledgePoint', array('getDataSource'));
$Model
->expects($this->any())
->method('getDataSource')
->will($this->returnValue($DataSource));
$Model->save(/* ... */);
In case you are wondering about the array(array()) for the datasource mock, this is required as the RestSource constructor doesn't supply a default value for the first argument (unlike the parent constructor).