Merge pull request #148 from OFFIS-DAI/scheduling-error-handling-canc…

…elling

Added handling for cancelled tasks for the callback raise exception

mango/util/scheduling.py

@@ -22,14 +22,17 @@
 
 def _raise_exceptions(fut: asyncio.Future):
     """
-    Inline function used as a callback to raise exceptions
+    Inline function used as a callback to raise exceptions.
     :param fut: The Future object of the task
     """
-    if fut.exception() is not None:
-        try:
-            raise fut.exception()
-        except Exception:
-            logger.exception("got exception in scheduled event")
+    try:
+        if fut.exception() is not None:
+            try:
+                raise fut.exception()
+            except BaseException:
+                logger.exception("got exception in scheduled event")
+    except asyncio.CancelledError:
+        pass  # if this happens the task has been cancelled by mango
 
 
 @dataclass

tests/unit_tests/util/scheduling_test.py

@@ -1,5 +1,6 @@
 import asyncio
 import datetime
+import logging
 import time
 
 import pytest
@@ -501,3 +502,27 @@ def on_stop(fut):
     # THEN
     assert len(l) == 2
     assert l[1] == 2
+
+
+class MyException(Exception):
+    pass
+
+
+@pytest.mark.asyncio
+async def test_exception(caplog):
+    # GIVEN
+    scheduler = Scheduler()
+    l = []
+
+    async def increase_counter():
+        raise MyException()
+
+    # WHEN
+    t = scheduler.schedule_task(PeriodicScheduledTask(increase_counter, 0.2))
+
+    # THEN
+    with caplog.at_level(logging.ERROR):
+        with pytest.raises(MyException):
+            await asyncio.wait_for(t, timeout=0.3)
+
+    assert "got exception in scheduled event" in caplog.text