Implement suggestions from the review

src/tribler/core/utilities/async_group/async_group.py

@@ -1,9 +1,10 @@
 import asyncio
+import logging
 from asyncio import CancelledError, Future, Task
 from contextlib import suppress
-from typing import Iterable, List, Set
+from typing import Coroutine, Iterable, List, Set
 
-from tribler.core.utilities.async_group.exceptions import CancelledException
+from tribler.core.utilities.async_group.exceptions import CanceledException
 
 
 class AsyncGroup:
@@ -22,14 +23,15 @@ class AsyncGroup:
     """
 
     def __init__(self):
+        self._logger = logging.getLogger(self.__class__.__name__)
         self._futures: Set[Future] = set()
-        self._cancelled = False
+        self._canceled = False
 
-    def add_task(self, coroutine) -> Task:
+    def add_task(self, coroutine: Coroutine) -> Task:
         """Add a coroutine to the group.
         """
-        if self._cancelled:
-            raise CancelledException()
+        if self._canceled:
+            raise CanceledException()
 
         task = asyncio.create_task(coroutine)
         self._futures.add(task)
@@ -47,10 +49,10 @@ async def cancel(self) -> List[Future]:
 
         Only active futures will be cancelled.
         """
-        if self._cancelled:
+        if self._canceled:
             return []
 
-        self._cancelled = True
+        self._canceled = True
 
         active = list(self._active(self._futures))
         for future in active:
@@ -63,11 +65,15 @@ async def cancel(self) -> List[Future]:
 
     @property
     def cancelled(self):
-        return self._cancelled
+        return self._canceled
 
     def _done_callback(self, future: Future):
-        self._futures.remove(future)
+        self._futures.discard(future)
 
     @staticmethod
     def _active(futures: Iterable[Future]) -> Iterable[Future]:
         return (future for future in futures if not future.done())
+
+    def __del__(self):
+        if active := list(self._active(self._futures)):
+            self._logger.error(f'AsyncGroup is destroying but {len(active)} futures are active')

src/tribler/core/utilities/async_group/exceptions.py

@@ -1,2 +1,2 @@
-class CancelledException(Exception):
+class CanceledException(Exception):
     """A coroutine can not be added to a cancelled AsyncGroup"""

src/tribler/core/utilities/async_group/tests/test_async_group.py

@@ -2,9 +2,10 @@
 from contextlib import suppress
 
 import pytest
+from _pytest.logging import LogCaptureFixture
 
 from tribler.core.utilities.async_group.async_group import AsyncGroup
-from tribler.core.utilities.async_group.exceptions import CancelledException
+from tribler.core.utilities.async_group.exceptions import CanceledException
 
 
 # pylint: disable=redefined-outer-name, protected-access
@@ -40,7 +41,7 @@ async def test_add_task(group: AsyncGroup):
 async def test_add_task_when_cancelled(group: AsyncGroup):
     await group.cancel()
 
-    with pytest.raises(CancelledException):
+    with pytest.raises(CanceledException):
         group.add_task(void())
 
 
@@ -114,3 +115,24 @@ async def test_auto_cleanup(group: AsyncGroup):
         await asyncio.gather(*group._futures, return_exceptions=True)
 
     assert not group._futures
+
+
+async def test_del_error(group: AsyncGroup, caplog: LogCaptureFixture):
+    """ In this test we add a single coroutine to the group and call __del__ before the coroutine is completed.
+
+    The group should add an error message to a log.
+    """
+    group.add_task(void())
+    group.__del__()
+    assert f'AsyncGroup is destroying but 1 futures are active' in caplog.text
+
+
+async def test_del_no_error(group: AsyncGroup, caplog: LogCaptureFixture):
+    """ In this test we add a single coroutine to the group and call __del__ after the coroutine is completed.
+
+    The group should not add an error message to a log.
+    """
+    group.add_task(void())
+    await group.wait()
+    group.__del__()
+    assert f'AsyncGroup is destroying but 1 futures are active' not in caplog.text