Improve calendar error handling to match best practices (#74891)

homeassistant/components/calendar/__init__.py

@@ -14,6 +14,7 @@ from homeassistant.components import frontend, http
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import STATE_OFF, STATE_ON
 from homeassistant.core import HomeAssistant
+from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers.config_validation import (  # noqa: F401
     PLATFORM_SCHEMA,
     PLATFORM_SCHEMA_BASE,
@@ -336,9 +337,14 @@ class CalendarEventView(http.HomeAssistantView):
         if not isinstance(entity, CalendarEntity):
             return web.Response(status=HTTPStatus.BAD_REQUEST)
 
-        calendar_event_list = await entity.async_get_events(
-            request.app["hass"], start_date, end_date
-        )
+        try:
+            calendar_event_list = await entity.async_get_events(
+                request.app["hass"], start_date, end_date
+            )
+        except HomeAssistantError as err:
+            return self.json_message(
+                f"Error reading events: {err}", HTTPStatus.INTERNAL_SERVER_ERROR
+            )
         return self.json(
             [
                 {

homeassistant/components/google/calendar.py

@@ -282,8 +282,7 @@ class GoogleCalendarEntity(CalendarEntity):
             async for result_page in result:
                 result_items.extend(result_page.items)
         except ApiException as err:
-            _LOGGER.error("Unable to connect to Google: %s", err)
-            return []
+            raise HomeAssistantError(str(err)) from err
         return [
             _get_calendar_event(event)
             for event in filter(self._event_filter, result_items)

tests/components/calendar/test_init.py

@@ -1,8 +1,10 @@
 """The tests for the calendar component."""
 from datetime import timedelta
 from http import HTTPStatus
+from unittest.mock import patch
 
 from homeassistant.bootstrap import async_setup_component
+from homeassistant.exceptions import HomeAssistantError
 import homeassistant.util.dt as dt_util
 
 
@@ -11,8 +13,6 @@ async def test_events_http_api(hass, hass_client):
     await async_setup_component(hass, "calendar", {"calendar": {"platform": "demo"}})
     await hass.async_block_till_done()
     client = await hass_client()
-    response = await client.get("/api/calendars/calendar.calendar_2")
-    assert response.status == HTTPStatus.BAD_REQUEST
     start = dt_util.now()
     end = start + timedelta(days=1)
     response = await client.get(
@@ -25,6 +25,36 @@ async def test_events_http_api(hass, hass_client):
     assert events[0]["summary"] == "Future Event"
 
 
+async def test_events_http_api_missing_fields(hass, hass_client):
+    """Test the calendar demo view."""
+    await async_setup_component(hass, "calendar", {"calendar": {"platform": "demo"}})
+    await hass.async_block_till_done()
+    client = await hass_client()
+    response = await client.get("/api/calendars/calendar.calendar_2")
+    assert response.status == HTTPStatus.BAD_REQUEST
+
+
+async def test_events_http_api_error(hass, hass_client):
+    """Test the calendar demo view."""
+    await async_setup_component(hass, "calendar", {"calendar": {"platform": "demo"}})
+    await hass.async_block_till_done()
+    client = await hass_client()
+    start = dt_util.now()
+    end = start + timedelta(days=1)
+
+    with patch(
+        "homeassistant.components.demo.calendar.DemoCalendar.async_get_events",
+        side_effect=HomeAssistantError("Failure"),
+    ):
+        response = await client.get(
+            "/api/calendars/calendar.calendar_1?start={}&end={}".format(
+                start.isoformat(), end.isoformat()
+            )
+        )
+        assert response.status == HTTPStatus.INTERNAL_SERVER_ERROR
+        assert await response.json() == {"message": "Error reading events: Failure"}
+
+
 async def test_calendars_http_api(hass, hass_client):
     """Test the calendar demo view."""
     await async_setup_component(hass, "calendar", {"calendar": {"platform": "demo"}})

tests/components/google/test_calendar.py

@@ -423,10 +423,7 @@ async def test_http_event_api_failure(
     mock_events_list({}, exc=ClientError())
 
     response = await client.get(upcoming_event_url())
-    assert response.status == HTTPStatus.OK
-    # A failure to talk to the server results in an empty list of events
-    events = await response.json()
-    assert events == []
+    assert response.status == HTTPStatus.INTERNAL_SERVER_ERROR
 
 
 @pytest.mark.freeze_time("2022-03-27 12:05:00+00:00")