Improve Monzo API errors, icon, and test coverage

homeassistant/components/monzo/coordinator.py

@@ -62,15 +62,19 @@ async def _async_update_data(self) -> MonzoData:
             raise ConfigEntryAuthFailed from err
         except InvalidMonzoAPIResponseError as err:
             message = "Invalid Monzo API response."
+            translation_key = "invalid_api_response"
             if err.missing_key:
                 _LOGGER.debug(
                     "%s\nMissing key: %s\nResponse:\n%s",
                     message,
                     err.missing_key,
                     pformat(err.response),
                 )
-                message += " Enabling debug logging for details."
-            raise UpdateFailed(message) from err
+                translation_key = "invalid_api_response_with_details"
+            raise UpdateFailed(
+                translation_domain=DOMAIN,
+                translation_key=translation_key,
+            ) from err
 
         data = MonzoData(
             accounts={account["id"]: account for account in accounts},

homeassistant/components/monzo/icons.json

@@ -1,4 +1,11 @@
 {
+  "entity": {
+    "event": {
+      "transaction": {
+        "default": "mdi:bank-transfer"
+      }
+    }
+  },
   "services": {
     "deposit_into_pot": {
       "service": "mdi:bank-transfer-in"

homeassistant/components/monzo/strings.json

@@ -78,6 +78,12 @@
     "invalid_account": {
       "message": "The selected device ({device_name}) is not an account belonging to this Monzo connection."
     },
+    "invalid_api_response": {
+      "message": "The Monzo API returned an invalid response."
+    },
+    "invalid_api_response_with_details": {
+      "message": "The Monzo API returned an invalid response. Enable debug logging for details."
+    },
     "invalid_device": {
       "message": "The selected Monzo device could not be found."
     },

tests/components/monzo/test_helpers.py

@@ -0,0 +1,25 @@
+"""Tests for Monzo helpers."""
+
+from homeassistant.components.monzo.helpers import (
+    get_account_name,
+    get_authenticated_owner_name,
+)
+
+
+def test_authenticated_owner_name_without_user_id() -> None:
+    """Test an owner cannot be selected without an authenticated user ID."""
+    assert get_authenticated_owner_name([], None) is None
+
+
+def test_account_name_ignores_malformed_owner() -> None:
+    """Test malformed owner metadata does not affect a joint account name."""
+    account = {
+        "name": "Joint Account",
+        "owners": [
+            "invalid owner",
+            {"preferred_name": "Jake Martin"},
+            {"preferred_name": "Jane Martin"},
+        ],
+    }
+
+    assert get_account_name(account) == "Joint Account — Jake Martin & Jane Martin"

tests/components/monzo/test_sensor.py

@@ -285,27 +285,44 @@ async def test_all_entities(
         )
 
 
+@pytest.mark.parametrize(
+    ("api_error", "expected_log_messages"),
+    [
+        pytest.param(
+            InvalidMonzoAPIResponseError(),
+            ("The Monzo API returned an invalid response",),
+            id="invalid-response",
+        ),
+        pytest.param(
+            InvalidMonzoAPIResponseError({"acc_id": None}, "account_id"),
+            (
+                "The Monzo API returned an invalid response. Enable debug logging for details",
+                "account_id",
+                "acc_id",
+            ),
+            id="missing-key",
+        ),
+    ],
+)
 async def test_update_failed(
     hass: HomeAssistant,
-    snapshot: SnapshotAssertion,
     monzo: AsyncMock,
     polling_config_entry: MockConfigEntry,
     freezer: FrozenDateTimeFactory,
     caplog: pytest.LogCaptureFixture,
+    api_error: InvalidMonzoAPIResponseError,
+    expected_log_messages: tuple[str, ...],
 ) -> None:
-    """Test all entities."""
+    """Test an invalid API response makes entities unavailable."""
     await setup_integration(hass, polling_config_entry)
 
-    monzo.user_account.accounts.side_effect = InvalidMonzoAPIResponseError(
-        {"acc_id": None}, "account_id"
-    )
+    monzo.user_account.accounts.side_effect = api_error
     freezer.tick(timedelta(minutes=10))
     async_fire_time_changed(hass)
     await hass.async_block_till_done(wait_background_tasks=True)
 
-    assert "Invalid Monzo API response." in caplog.text
-    assert "account_id" in caplog.text
-    assert "acc_id" in caplog.text
+    for message in expected_log_messages:
+        assert message in caplog.text
 
     entity_id = await async_get_entity_id(
         hass, TEST_ACCOUNTS[0]["id"], ACCOUNT_SENSORS[0]