Fixed single stream update exception aborting all parallel updates.

tests/test_stream_monitor.py

@@ -864,6 +864,58 @@ class TestUpdateAllStreamsMixed:
         assert result.successful_checks == 1
         assert result.failed_checks == 1
 
+    async def test_exception_isolated_to_failing_domain(
+        self,
+        stream_repo: StreamRepository,
+        subscription_repo: SubscriptionRepository,
+    ) -> None:
+        """Count an unhandled exception as a failure without aborting other updates."""
+        owncast = _StubOwncastClient(
+            stream_state=StreamState(
+                domain="ok.com",
+                title="Title",
+                last_disconnect_time="2026-01-01T00:00:00Z",
+            ),
+        )
+        # Patch get_stream_state to raise for one specific domain
+        original_get_state = owncast.get_stream_state
+
+        async def raising_get_state(domain: str) -> StreamState | None:
+            if domain == "raise.com":
+                msg = "simulated DB error"
+                raise RuntimeError(msg)
+            return await original_get_state(domain)
+
+        owncast.get_stream_state = raising_get_state  # type: ignore[assignment]
+
+        client = _StubMatrixClient()
+        monitor, _ = _make_monitor(
+            owncast_client=owncast,
+            stream_repo=stream_repo,
+            subscription_repo=subscription_repo,
+            client=client,
+        )
+
+        await _seed_stream(
+            stream_repo,
+            subscription_repo,
+            domain="raise.com",
+            last_disconnect_time="2026-01-01T00:00:00Z",
+        )
+        await _seed_stream(
+            stream_repo,
+            subscription_repo,
+            domain="ok.com",
+            room_id="!room2:matrix.org",
+            title="Title",
+            last_disconnect_time="2026-01-01T00:00:00Z",
+        )
+
+        result = await monitor.update_all_streams(["raise.com", "ok.com"])
+        assert result.total_streams == 2
+        assert result.failed_checks == 1
+        assert result.successful_checks == 1
+
 
 class TestStreamMonitorMetrics:
     """Stream monitor metrics recording."""