Add exception handling to Sonarr (#4569)

* Add exception handling to request call to prevent
failure in setup_platform if host is down

* update for comments

* update test for state being none

* remove unused import

tests/components/sensor/test_sonarr.py

@@ -10,6 +10,11 @@ from homeassistant.components.sensor import sonarr
 from tests.common import get_test_home_assistant
 
 
+def mocked_exception(*args, **kwargs):
+    """Mock exception thrown by requests.get."""
+    raise OSError
+
+
 def mocked_requests_get(*args, **kwargs):
     """Mock requests.get invocations."""
     class MockResponse:
@@ -814,3 +819,23 @@ class TestSonarrSetup(unittest.TestCase):
                 'S04E11',
                 device.device_state_attributes["Bob's Burgers"]
             )
+
+    @unittest.mock.patch('requests.get', side_effect=mocked_exception)
+    def test_exception_handling(self, req_mock):
+        """Tests exception being handled"""
+        config = {
+            'platform': 'sonarr',
+            'api_key': 'foo',
+            'days': '1',
+            'unit': 'GB',
+            "include_paths": [
+                '/data'
+            ],
+            'monitored_conditions': [
+                'upcoming'
+            ]
+        }
+        sonarr.setup_platform(self.hass, config, self.add_devices, None)
+        for device in self.DEVICES:
+            device.update()
+            self.assertEqual(None, device.state)