WIP: Migrate scene to async + homeassistant scene async (#4665)

* Migrate scene to async + homeassistant scene async

* fix lint

* Update state.py

* Fix tests

tests/components/scene/test_init.py

@@ -0,0 +1,110 @@
+"""The tests for the Scene component."""
+import unittest
+
+from homeassistant.bootstrap import setup_component
+from homeassistant import loader
+from homeassistant.components import light, scene
+
+from tests.common import get_test_home_assistant
+
+
+class TestScene(unittest.TestCase):
+    """Test the scene component."""
+
+    def setUp(self):  # pylint: disable=invalid-name
+        """Setup things to be run when tests are started."""
+        self.hass = get_test_home_assistant()
+
+    def tearDown(self):  # pylint: disable=invalid-name
+        """Stop everything that was started."""
+        self.hass.stop()
+
+    def test_config_yaml_alias_anchor(self):
+        """Test the usage of YAML aliases and anchors.
+
+        The following test scene configuration is equivalent to:
+
+        scene:
+          - name: test
+            entities:
+              light_1: &light_1_state
+                state: 'on'
+                brightness: 100
+              light_2: *light_1_state
+
+        When encountering a YAML alias/anchor, the PyYAML parser will use a
+        reference to the original dictionary, instead of creating a copy, so
+        care needs to be taken to not modify the original.
+        """
+        test_light = loader.get_component('light.test')
+        test_light.init()
+
+        self.assertTrue(setup_component(self.hass, light.DOMAIN, {
+            light.DOMAIN: {'platform': 'test'}
+        }))
+
+        light_1, light_2 = test_light.DEVICES[0:2]
+
+        light.turn_off(self.hass, [light_1.entity_id, light_2.entity_id])
+
+        self.hass.block_till_done()
+
+        entity_state = {
+            'state': 'on',
+            'brightness': 100,
+        }
+        self.assertTrue(setup_component(self.hass, scene.DOMAIN, {
+            'scene': [{
+                'name': 'test',
+                'entities': {
+                    light_1.entity_id: entity_state,
+                    light_2.entity_id: entity_state,
+                }
+            }]
+        }))
+
+        scene.activate(self.hass, 'scene.test')
+        self.hass.block_till_done()
+
+        self.assertTrue(light_1.is_on)
+        self.assertTrue(light_2.is_on)
+        self.assertEqual(100,
+                         light_1.last_call('turn_on')[1].get('brightness'))
+        self.assertEqual(100,
+                         light_2.last_call('turn_on')[1].get('brightness'))
+
+    def test_activate_scene(self):
+        """Test active scene."""
+        test_light = loader.get_component('light.test')
+        test_light.init()
+
+        self.assertTrue(setup_component(self.hass, light.DOMAIN, {
+            light.DOMAIN: {'platform': 'test'}
+        }))
+
+        light_1, light_2 = test_light.DEVICES[0:2]
+
+        light.turn_off(self.hass, [light_1.entity_id, light_2.entity_id])
+
+        self.hass.block_till_done()
+
+        self.assertTrue(setup_component(self.hass, scene.DOMAIN, {
+            'scene': [{
+                'name': 'test',
+                'entities': {
+                    light_1.entity_id: 'on',
+                    light_2.entity_id: {
+                        'state': 'on',
+                        'brightness': 100,
+                    }
+                }
+            }]
+        }))
+
+        scene.activate(self.hass, 'scene.test')
+        self.hass.block_till_done()
+
+        self.assertTrue(light_1.is_on)
+        self.assertTrue(light_2.is_on)
+        self.assertEqual(100,
+                         light_2.last_call('turn_on')[1].get('brightness'))