Testing CI query object

[fastzen]

I'm working my way through the book (very nice work) in order to retrofit tests into some CI code that I've taken over.

Everything goes fine until I try mocking a CI query object, for which the book has no example.

My additional function for Value_model:

    public function getAnyForTracker($tracker_id)
{
    $sql = "select * from trackers where tracker_id = ?";
    $query = $this->db->query($sql, array($tracker_id));
    return $query->result();
}

and my test is:

public function testGetAnyForTracker()
{
    $dbdata = array( array( 'tracker_id' => 'website_visits', 'value' => '127.0.0.1', 'created_at' => '' ),
                     array( 'tracker_id' => 'website_visits', 'value' => '66.121.684.92', 'created_at' => '' ),
                     array( 'tracker_id' => 'website_visits', 'value' => '84.124.152.11', 'created_at' => '' ) );

    $model = new Value_model();
    $model->db = Mockery::mock($model->db);
    $result = Mockery::mock('db result');

    $result->shouldReceive('result_array')->once()->andReturn($dbdata);
    $model->db->shouldReceive('query')
              ->once()
              ->with('tracker_id')
              ->andReturn($result);

    $result = $model->getAnyForTracker('website_visits');

}

I then get the following result:

1) Value_modelTest::testGetAnyForTracker
Mockery\Exception: No matching handler found for CI_DB_mysql_driver::query("select * from trackers where tracker_id = ?", Array). Either the method was unexpected or its arguments matched no expected argument list for this method

I don't actually get round to making assertions about the return value as I'm not sure how to correct that error in the result.

Any pointers would be gratefully received.