fix problem of streaming errors causing a unsubscribe

This commit fixes a bug which caused a subscription to unsubscribe when
a streaming error was received since a uninitialized value was accessed.
In addition errors happening in the subscription handling are now
bubbled up to the dataserver to show up in the logs.

Author: Tobias Ahrens

CHANGELOG.md

@@ -1,7 +1,11 @@
 # Labone Python API Changelog
 
-## Version 3.1.1
+## Version 3.1.2
+* Fix bug which caused streaming errors to cancel the subscriptions
+* Raise severity of errors during subscriptions to `FAILED` to cause a data server
+  log entry.
 
+## Version 3.1.1
 * Add support for Python 3.13
 
 ## Version 3.1.0

src/labone/core/subscription.py

@@ -496,6 +496,7 @@ def _distribute_to_data_queues(
             # error should not be raised here since this would disconnect the
             # subscription.
             logger.exception(err.args[0])
+            return
         except ValueError as err:  # pragma: no cover
             self._data_queues = [
                 data_queue().disconnect()  # type: ignore[union-attr] # supposed to throw
@@ -539,4 +540,4 @@ async def capnp_callback(
             list(map(self._distribute_to_data_queues, call_input.values))
             fulfiller.fulfill()
         except Exception as err:  # noqa: BLE001
-            fulfiller.reject(zhinst.comms.Fulfiller.DISCONNECTED, err.args[0])
+            fulfiller.reject(zhinst.comms.Fulfiller.FAILED, err.args[0])

tests/core/test_subscription.py

@@ -1,10 +1,12 @@
 """Tests for the `labone.core.subscription` module."""
 
 import asyncio
+import logging
+from unittest.mock import MagicMock
 
 import pytest
 
-from labone.core import errors
+from labone.core import errors, hpk_schema
 from labone.core.subscription import (
     CircularDataQueue,
     DataQueue,
@@ -257,6 +259,86 @@ def test_streaming_handle_with_parser_callback():
     )
 
 
+@pytest.mark.asyncio
+async def test_capnp_callback(caplog):
+    streaming_handle = StreamingHandle()
+    queue = DataQueue(
+        path="dummy",
+        handle=streaming_handle,
+    )
+    call_param = hpk_schema.StreamingHandleSendValuesParams()
+    values = call_param.init_values(2)
+
+    values[0].init_metadata(timestamp=0, path="dummy")
+    values[0].init_value(int64=42)
+
+    values[1].init_metadata(timestamp=1, path="dummy")
+    values[1].init_value(double=22.0)
+
+    fulfiller = MagicMock()
+    with caplog.at_level(logging.ERROR):
+        await streaming_handle.capnp_callback(0, 0, call_param, fulfiller)
+    assert "" in caplog.text
+    assert queue.qsize() == 2
+    assert queue.get_nowait() == AnnotatedValue(value=42, path="dummy", timestamp=0)
+    assert queue.get_nowait() == AnnotatedValue(value=22.0, path="dummy", timestamp=1)
+    fulfiller.fulfill.assert_called_once()
+
+
+@pytest.mark.asyncio
+async def test_streaming_error(caplog):
+    streaming_handle = StreamingHandle()
+    queue = DataQueue(
+        path="dummy",
+        handle=streaming_handle,
+    )
+    call_param = hpk_schema.StreamingHandleSendValuesParams()
+    values = call_param.init_values(1)
+    values[0].init_metadata(timestamp=0, path="dummy")
+    values[0].init_value().init_streamingError(
+        code=1,
+        message="test error",
+        category="unknown",
+    )
+    fulfiller = MagicMock()
+    with caplog.at_level(logging.ERROR):
+        await streaming_handle.capnp_callback(0, 0, call_param, fulfiller)
+    assert "test error" in caplog.text
+    assert queue.qsize() == 0
+    fulfiller.fulfill.assert_called_once()
+
+
+@pytest.mark.asyncio
+async def test_streaming_error_with_value(caplog):
+    streaming_handle = StreamingHandle()
+    queue = DataQueue(
+        path="dummy",
+        handle=streaming_handle,
+    )
+    call_param = hpk_schema.StreamingHandleSendValuesParams()
+    values = call_param.init_values(2)
+
+    # Fist value is a streaming error
+    values[0].init_metadata(timestamp=0, path="dummy")
+    values[0].init_value().init_streamingError(
+        code=1,
+        message="test error",
+        category="unknown",
+    )
+
+    # Second value is a normal value
+    values[1].init_metadata(timestamp=0, path="dummy")
+    values[1].init_value(int64=42)
+
+    fulfiller = MagicMock()
+    with caplog.at_level(logging.ERROR):
+        await streaming_handle.capnp_callback(0, 0, call_param, fulfiller)
+    assert "test error" in caplog.text
+    assert queue.qsize() == 1
+    assert queue.get_nowait() == AnnotatedValue(value=42, path="dummy", timestamp=0)
+    fulfiller.fulfill.assert_called_once()
+
+
 @pytest.mark.asyncio
 async def test_distinct_data_queue_put_no_wait_new_value():
     subscription = FakeSubscription()