Add aurora sensor (#6003)

* Add aurora sensor

* allow custom forecast threshold for aurora binary sensor

* move AuroraGateway functionality to Aurora data object to conform with HA standards

tests/components/binary_sensor/test_aurora.py

@@ -0,0 +1,95 @@
+"""The tests for the Aurora sensor platform."""
+import re
+import unittest
+
+import requests_mock
+
+from homeassistant.components.binary_sensor import aurora
+from tests.common import load_fixture, get_test_home_assistant
+
+
+class TestAuroraSensorSetUp(unittest.TestCase):
+    """Test the aurora platform."""
+
+    def setUp(self):
+        """Initialize values for this testcase class."""
+        self.hass = get_test_home_assistant()
+        self.lat = 37.8267
+        self.lon = -122.423
+        self.hass.config.latitude = self.lat
+        self.hass.config.longitude = self.lon
+        self.entities = []
+
+    def tearDown(self):  # pylint: disable=invalid-name
+        """Stop everything that was started."""
+        self.hass.stop()
+
+    @requests_mock.Mocker()
+    def test_setup_and_initial_state(self, mock_req):
+        """Test that the component is created and initialized as expected."""
+        uri = re.compile(
+            "http://services\.swpc\.noaa\.gov/text/aurora-nowcast-map\.txt"
+        )
+        mock_req.get(uri, text=load_fixture('aurora.txt'))
+
+        entities = []
+
+        def mock_add_entities(new_entities, update_before_add=False):
+            """Mock add entities."""
+            if update_before_add:
+                for entity in new_entities:
+                    entity.update()
+
+            for entity in new_entities:
+                entities.append(entity)
+
+        config = {
+            "name": "Test",
+            "forecast_threshold": 75
+        }
+        aurora.setup_platform(self.hass, config, mock_add_entities)
+
+        aurora_component = entities[0]
+        self.assertEqual(len(entities), 1)
+        self.assertEqual(aurora_component.name, "Test")
+        self.assertEqual(
+            aurora_component.device_state_attributes["visibility_level"],
+            '0'
+        )
+        self.assertEqual(
+            aurora_component.device_state_attributes["message"],
+            "nothing's out"
+        )
+        self.assertFalse(aurora_component.is_on)
+
+    @requests_mock.Mocker()
+    def test_custom_threshold_works(self, mock_req):
+        """Test that the the config can take a custom forecast threshold."""
+        uri = re.compile(
+            "http://services\.swpc\.noaa\.gov/text/aurora-nowcast-map\.txt"
+        )
+        mock_req.get(uri, text=load_fixture('aurora.txt'))
+
+        entities = []
+
+        def mock_add_entities(new_entities, update_before_add=False):
+            """Mock add entities."""
+            if update_before_add:
+                for entity in new_entities:
+                    entity.update()
+
+            for entity in new_entities:
+                entities.append(entity)
+
+        config = {
+            "name": "Test",
+            "forecast_threshold": 1
+        }
+        self.hass.config.longitude = 5
+        self.hass.config.latitude = 5
+
+        aurora.setup_platform(self.hass, config, mock_add_entities)
+
+        aurora_component = entities[0]
+        self.assertEquals(aurora_component.aurora_data.visibility_level, '5')
+        self.assertTrue(aurora_component.is_on)