title: Unit Tests with read-only custom Datasource in Cakephp
body: <p>I am currently in the process of writing some Unit Tests for my CakePHP application. I have a custom <code>datasource</code> for a few of my models. This is a <em>read only</em> datasource. I want to run some unit tests using this datasource but can't seem to get it working. </p>
  
  <p>I have created a fixture with the following at the top:</p>
  
  <pre><code>public $useDbConfig = 'test_datafeeds';
  </code></pre>
  
  <p>But I get a load of errors thrown back at me. If I delete all my fixtures from the DataTest it works, however it uses all the actual data in the actual database too - for my tests I would prefer to use the dummy data I have sent up for the data in my database. </p>
  
  <p>I have managed to create static fixtures using dummy data to mock the datasource, but i'd also prefer the option to use the actual datasource in tests. </p>
  
  <p>Some of the errors I am getting: </p>
  
  <pre><code>Notice: Undefined index: prefix in lib/Cake/TestSuite/Fixture/CakeFixtureManager.php on line 169
  
  Warning: in_array() expects parameter 2 to be array, null given in lib/Cake/TestSuite/Fixture/CakeFixtureManager.php on line 171
  
  Warning: in_array() expects parameter 2 to be array, null given in lib/Cake/TestSuite/Fixture/CakeFixtureManager.php on line 174
  
  Fatal error: Call to undefined method DataFeedSource::execute() in lib/Cake/Test/Suite/Fixture/CakeTestFixture.php on line 194
  </code></pre>