public function testIsValueChanged() { // load the model $collection = new Mage_Core_Model_Resource_Config_Data_Collection(); $collection->addFieldToFilter('path', self::SAMPLE_CONFIG_PATH)->addFieldToFilter('scope_id', 0)->addFieldToFilter('scope', 'default'); foreach ($collection as $configData) { $this->_model = $configData; break; } $this->assertNotEmpty($this->_model->getId()); // assert $this->assertFalse($this->_model->isValueChanged()); $this->_model->setValue(uniqid()); $this->assertTrue($this->_model->isValueChanged()); }