public function testPopulateInput() { $params = array('type' => 'multiselect', 'can_be_empty' => true, 'source_model' => 'some_model', 'someArr' => array('testVar' => 'testVal')); $this->_model->setData($params, 'scope'); $elementMock = $this->getMock('Varien_Data_Form_Element_Text', array('setOriginalData'), array(), '', false); unset($params['someArr']); $elementMock->expects($this->once())->method('setOriginalData')->with($params); $this->_model->populateInput($elementMock); }