text: """The tests for the MQTT sensor platform."""
  import unittest
  
  from homeassistant.bootstrap import _setup_component
  import homeassistant.components.sensor as sensor
  from tests.common import mock_mqtt_component, fire_mqtt_message
  
  from tests.common import get_test_home_assistant
  
  
  class TestSensorMQTT(unittest.TestCase):
      """Test the MQTT sensor."""
  
      def setUp(self):  # pylint: disable=invalid-name
          """Setup things to be run when tests are started."""
          self.hass = get_test_home_assistant()
          mock_mqtt_component(self.hass)
  
      def tearDown(self):  # pylint: disable=invalid-name
          """Stop down everything that was started."""
          self.hass.stop()
  
      def test_setting_sensor_value_via_mqtt_message(self):
          """Test the setting of the value via MQTT."""
          self.hass.config.components = ['mqtt']
          assert _setup_component(self.hass, sensor.DOMAIN, {
              sensor.DOMAIN: {
                  'platform': 'mqtt',
                  'name': 'test',
                  'state_topic': 'test-topic',
                  'unit_of_measurement': 'fav unit'
              }
          })
  
          fire_mqtt_message(self.hass, 'test-topic', '100')
          self.hass.block_till_done()
          state = self.hass.states.get('sensor.test')
  
          self.assertEqual('100', state.state)
          self.assertEqual('fav unit',
                           state.attributes.get('unit_of_measurement'))
  
      def test_setting_sensor_value_via_mqtt_json_message(self):
          """Test the setting of the value via MQTT with JSON playload."""
          self.hass.config.components = ['mqtt']
          assert _setup_component(self.hass, sensor.DOMAIN, {
              sensor.DOMAIN: {
                  'platform': 'mqtt',
                  'name': 'test',
                  'state_topic': 'test-topic',
                  'unit_of_measurement': 'fav unit',
                  'value_template': '{{ value_json.val }}'
              }
          })
  
          fire_mqtt_message(self.hass, 'test-topic', '{ "val": "100" }')
          self.hass.block_till_done()
          state = self.hass.states.get('sensor.test')
  
          self.assertEqual('100', state.state)
  