Check for errors when creating backups using supervisor (#137220)

* Check for errors when creating backups using supervisor

* Improve error reporting when there's no backup reference

homeassistant/components/hassio/backup.py

@@ -354,6 +354,7 @@ class SupervisorBackupReaderWriter(BackupReaderWriter):
         """Wait for a backup to complete."""
         backup_complete = asyncio.Event()
         backup_id: str | None = None
+        create_errors: list[dict[str, str]] = []
 
         @callback
         def on_job_progress(data: Mapping[str, Any]) -> None:
@@ -361,6 +362,7 @@ class SupervisorBackupReaderWriter(BackupReaderWriter):
             nonlocal backup_id
             if data.get("done") is True:
                 backup_id = data.get("reference")
+                create_errors.extend(data.get("errors", []))
                 backup_complete.set()
 
         unsub = self._async_listen_job_events(backup.job_id, on_job_progress)
@@ -369,8 +371,11 @@ class SupervisorBackupReaderWriter(BackupReaderWriter):
             await backup_complete.wait()
         finally:
             unsub()
-        if not backup_id:
-            raise BackupReaderWriterError("Backup failed")
+        if not backup_id or create_errors:
+            # We should add more specific error handling here in the future
+            raise BackupReaderWriterError(
+                f"Backup failed: {create_errors or 'no backup_id'}"
+            )
 
         async def open_backup() -> AsyncIterator[bytes]:
             try:

tests/components/hassio/test_backup.py

@@ -1360,11 +1360,40 @@ async def test_reader_writer_create_partial_backup_error(
     assert supervisor_client.backups.partial_backup.call_count == 1
 
 
+@pytest.mark.parametrize(
+    "supervisor_event",
+    [
+        # Missing backup reference
+        {
+            "event": "job",
+            "data": {
+                "done": True,
+                "uuid": TEST_JOB_ID,
+            },
+        },
+        # Errors
+        {
+            "event": "job",
+            "data": {
+                "done": True,
+                "errors": [
+                    {
+                        "type": "BackupMountDownError",
+                        "message": "test_mount is down, cannot back-up to it",
+                    }
+                ],
+                "uuid": TEST_JOB_ID,
+                "reference": "test_slug",
+            },
+        },
+    ],
+)
 @pytest.mark.usefixtures("hassio_client", "setup_integration")
 async def test_reader_writer_create_missing_reference_error(
     hass: HomeAssistant,
     hass_ws_client: WebSocketGenerator,
     supervisor_client: AsyncMock,
+    supervisor_event: dict[str, Any],
 ) -> None:
     """Test missing reference error when generating a backup."""
     client = await hass_ws_client(hass)
@@ -1395,13 +1424,7 @@ async def test_reader_writer_create_missing_reference_error(
     assert supervisor_client.backups.partial_backup.call_count == 1
 
     await client.send_json_auto_id(
-        {
-            "type": "supervisor/event",
-            "data": {
-                "event": "job",
-                "data": {"done": True, "uuid": TEST_JOB_ID},
-            },
-        }
+        {"type": "supervisor/event", "data": supervisor_event}
     )
     response = await client.receive_json()
     assert response["success"]