Fix for #8253 "Unclosed client session" when initialization fails (#8290

)

(cherry picked from commit 5fd2946)

CHANGES/8253.bugfix

@@ -0,0 +1 @@
+Fixed "Unclosed client session" when initialization of ClientSession fails -- by :user:`NewGlad`.

CONTRIBUTORS.txt

@@ -27,6 +27,7 @@ Alexander Shorin
 Alexander Travov
 Alexandru Mihai
 Alexey Firsov
+Alexey Nikitin
 Alexey Popravka
 Alexey Stepanov
 Amin Etesamian

aiohttp/client.py

@@ -268,6 +268,20 @@ def __init__(
 
         if connector is None:
             connector = TCPConnector(loop=loop)
+        loop = asyncio.get_running_loop()
+
+        if connector is None:
+            connector = TCPConnector()
+        # Initialize these three attrs before raising any exception,
+        # they are used in __del__
+        self._connector = connector
+        self._loop = loop
+        if loop.get_debug():
+            self._source_traceback: Optional[traceback.StackSummary] = (
+                traceback.extract_stack(sys._getframe(1))
+            )
+        else:
+            self._source_traceback = None
 
         if connector._loop is not loop:
             raise RuntimeError("Session and connector has to use same event loop")

tests/test_client_session.py

@@ -885,3 +885,8 @@ async def test_build_url_returns_expected_url(
 ) -> None:
     session = await create_session(base_url)
     assert session._build_url(url) == expected_url
+
+
+async def test_instantiation_with_invalid_timeout_value():
+    with pytest.raises(ValueError, match="timeout parameter cannot be .*"):
+        ClientSession(timeout=1)