Close SQLite connection if session is deleted and thread is still running

aiohttp_client_cache/backends/sqlite.py

@@ -103,6 +103,20 @@ async def _init_db(self):
         )
         return self._connection
 
+    def __del__(self):
+        """If the aiosqlite connection is still open when this object is deleted, force its thread
+        to close by emptying its internal queue and setting its ``_running`` flag to ``False``.
+        This is basically a last resort to avoid hanging the application if this backend is used
+        without the CachedSession contextmanager.
+
+        Note: Since this uses internal attributes, it has the potential to break in future versions
+        of aiosqlite.
+        """
+        if self._connection is not None:
+            self._connection._tx.queue.clear()
+            self._connection._running = False
+            self._connection = None
+
     @asynccontextmanager
     async def bulk_commit(self):
         """Contextmanager to more efficiently write a large number of records at once

noxfile.py

@@ -32,7 +32,7 @@
 def test(session):
     """Run tests for a specific python version"""
     test_paths = session.posargs or [UNIT_TESTS]
-    session.install('.', 'pytest', 'pytest-xdist', 'requests-mock', 'timeout-decorator')
+    session.install('.', 'pytest', 'pytest-aiohttp', 'pytest-asyncio', 'pytest-xdist')
 
     cmd = f'pytest -rs {XDIST_ARGS}'
     session.run(*cmd.split(' '), *test_paths)

pyproject.toml

@@ -70,6 +70,7 @@ docs        = ["furo", "linkify-it-py", "markdown-it-py", "myst-parser", "python
 
 [tool.poetry.dev-dependencies]
 # For unit + integration tests
+async-timeout   = ">=4.0"
 brotli          = ">=1.0"
 pytest          = ">=6.2"
 pytest-aiohttp  = "^0.3"

test/integration/base_backend_test.py

@@ -8,6 +8,7 @@
 from uuid import uuid4
 
 import pytest
+from async_timeout import timeout
 from itsdangerous.exc import BadSignature
 from itsdangerous.serializer import Serializer
 
@@ -35,13 +36,17 @@ class BaseBackendTest:
 
     @asynccontextmanager
     async def init_session(self, clear=True, **kwargs) -> AsyncIterator[CachedSession]:
+        session = await self._init_session(clear=clear, **kwargs)
+        async with session:
+            yield session
+
+    async def _init_session(self, clear=True, **kwargs) -> CachedSession:
         kwargs.setdefault('allowed_methods', ALL_METHODS)
         cache = self.backend_class(CACHE_NAME, **self.init_kwargs, **kwargs)
         if clear:
             await cache.clear()
 
-        async with CachedSession(cache=cache, **self.init_kwargs, **kwargs) as session:
-            yield session
+        return CachedSession(cache=cache, **self.init_kwargs, **kwargs)
 
     @pytest.mark.parametrize('method', HTTPBIN_METHODS)
     @pytest.mark.parametrize('field', ['params', 'data', 'json'])
@@ -100,6 +105,20 @@ async def get_url(mysession, url):
             responses = await asyncio.gather(*tasks)
             assert all([r.from_cache is True for r in responses])
 
+    async def test_without_contextmanager(self):
+        """Test that the cache backend can be safely used without the CachedSession contextmanager.
+        An "unclosed ClientSession" warning is expected here, however.
+        """
+        # Timeout to avoid hanging if the test fails
+        async with timeout(5.0):
+            session = await self._init_session()
+            await session.get(httpbin('get'))
+            del session
+
+            session = await self._init_session(clear=False)
+            r = await session.get(httpbin('get'))
+            assert r.from_cache is True
+
     async def test_request__expire_after(self):
         async with self.init_session() as session:
             await session.get(httpbin('get'), expire_after=1)

test/integration/test_memory.py

@@ -23,6 +23,14 @@ async def test_content_reset(self):
             content_2 = await cached_response_2.read()
             assert content_1 == content_2 == original_content
 
+    async def test_without_contextmanager(self):
+        """Test that the cache backend can be safely used without the CachedSession contextmanager.
+        An "unclosed ClientSession" warning is expected here, however.
+        """
+        session = await self._init_session()
+        await session.get(httpbin('get'))
+        del session
+
     # Serialization tests don't apply to in-memory cache
     async def test_serializer__pickle(self):
         pass

test/integration/test_sqlite.py

@@ -1,5 +1,6 @@
 import asyncio
 import os
+from contextlib import asynccontextmanager
 from tempfile import gettempdir
 from unittest.mock import MagicMock, patch
 
@@ -53,17 +54,22 @@ async def test_concurrent_bulk_commit(self, mock_sqlite):
         mock_connection = AsyncMock()
         mock_sqlite.connect = AsyncMock(return_value=mock_connection)
 
-        async with self.init_cache() as cache:
+        @asynccontextmanager
+        async def bulk_commit_ctx():
+            async with self.init_cache() as cache:
+
+                async def bulk_commit_items(n_items):
+                    async with cache.bulk_commit():
+                        for i in range(n_items):
+                            await cache.write(f'key_{n_items}_{i}', f'value_{i}')
 
-            async def bulk_commit_items(n_items):
-                async with cache.bulk_commit():
-                    for i in range(n_items):
-                        await cache.write(f'key_{n_items}_{i}', f'value_{i}')
+                yield bulk_commit_items
 
-        assert mock_connection.commit.call_count == 1
-        tasks = [asyncio.create_task(bulk_commit_items(n)) for n in [10, 100, 1000, 10000]]
-        await asyncio.gather(*tasks)
-        assert mock_connection.commit.call_count == 5
+        async with bulk_commit_ctx() as bulk_commit_items:
+            assert mock_connection.commit.call_count == 1
+            tasks = [asyncio.create_task(bulk_commit_items(n)) for n in [10, 100, 1000, 10000]]
+            await asyncio.gather(*tasks)
+            assert mock_connection.commit.call_count == 5
 
     async def test_fast_save(self):
         async with self.init_cache(index=1, fast_save=True) as cache_1, self.init_cache(

test/unit/test_base_backend.py

@@ -1,19 +1,14 @@
 import pickle
-from sys import version_info
 from unittest.mock import MagicMock, patch
 
 import pytest
 
 from aiohttp_client_cache import CachedResponse
 from aiohttp_client_cache.backends import CacheBackend, DictCache, get_placeholder_backend
+from test.conftest import skip_37
 
 TEST_URL = 'https://test.com'
 
-pytestmark = pytest.mark.asyncio
-skip_py37 = pytest.mark.skipif(
-    version_info < (3, 8), reason='Test requires AsyncMock from python 3.8+'
-)
-
 
 def get_mock_response(**kwargs):
     response_kwargs = {
@@ -71,7 +66,7 @@ async def test_get_response__cache_miss(mock_delete):
     mock_delete.assert_not_called()
 
 
-@skip_py37
+@skip_37
 @patch.object(CacheBackend, 'delete')
 @patch.object(CacheBackend, 'is_cacheable', return_value=False)
 async def test_get_response__cache_expired(mock_is_cacheable, mock_delete):
@@ -84,7 +79,7 @@ async def test_get_response__cache_expired(mock_is_cacheable, mock_delete):
     mock_delete.assert_called_with('request-key')
 
 
-@skip_py37
+@skip_37
 @pytest.mark.parametrize('error_type', [AttributeError, KeyError, TypeError, pickle.PickleError])
 @patch.object(CacheBackend, 'delete')
 @patch.object(DictCache, 'read')
@@ -99,7 +94,7 @@ async def test_get_response__cache_invalid(mock_read, mock_delete, error_type):
     mock_delete.assert_not_called()
 
 
-@skip_py37
+@skip_37
 @patch.object(DictCache, 'read', return_value=object())
 async def test_get_response__quiet_serde_error(mock_read):
     """Test for a quiet deserialization error in which no errors are raised but attributes are
@@ -113,7 +108,7 @@ async def test_get_response__quiet_serde_error(mock_read):
     assert response is None
 
 
-@skip_py37
+@skip_37
 async def test_save_response():
     cache = CacheBackend()
     mock_response = get_mock_response()
@@ -126,7 +121,7 @@ async def test_save_response():
     assert await cache.redirects.read(redirect_key) == 'key'
 
 
-@skip_py37
+@skip_37
 async def test_save_response__manual_save():
     """Manually save a response with no cache key provided"""
     cache = CacheBackend()
@@ -193,7 +188,7 @@ async def test_has_url():
     assert not await cache.has_url('https://test.com/some_other_path')
 
 
-@skip_py37
+@skip_37
 @patch('aiohttp_client_cache.backends.base.create_key')
 async def test_create_key(mock_create_key):
     """Actual logic is in cache_keys module; just test to make sure it gets called correctly"""
@@ -244,7 +239,7 @@ async def test_is_cacheable(method, status, disabled, expired, filter_return, ex
     assert await cache.is_cacheable(mock_response) is expected_result
 
 
-@skip_py37
+@skip_37
 @pytest.mark.parametrize(
     'method, status, disabled, expired, body, expected_result',
     [