Fix test

Author: NoahStapp

pymongo/asynchronous/mongo_client.py

@@ -2268,15 +2268,14 @@ async def _tmp_session(
         self, session: Optional[client_session.AsyncClientSession]
     ) -> AsyncGenerator[Optional[client_session.AsyncClientSession], None]:
         """If provided session is None, lend a temporary session."""
+        if session is not None and not isinstance(session, client_session.AsyncClientSession):
+            raise ValueError(
+                f"'session' argument must be an AsyncClientSession or None, not {type(session)}"
+            )
 
         # Check for a bound session. If one exists, treat it as an explicitly passed session.
         session = session or self._get_bound_session()
-
-        if session is not None:
-            if not isinstance(session, client_session.AsyncClientSession):
-                raise ValueError(
-                    f"'session' argument must be an AsyncClientSession or None, not {type(session)}"
-                )
+        if session:
             # Don't call end_session.
             yield session
             return

pymongo/synchronous/mongo_client.py

@@ -2264,15 +2264,14 @@ def _tmp_session(
         self, session: Optional[client_session.ClientSession]
     ) -> Generator[Optional[client_session.ClientSession], None]:
         """If provided session is None, lend a temporary session."""
+        if session is not None and not isinstance(session, client_session.ClientSession):
+            raise ValueError(
+                f"'session' argument must be a ClientSession or None, not {type(session)}"
+            )
 
         # Check for a bound session. If one exists, treat it as an explicitly passed session.
         session = session or self._get_bound_session()
-
-        if session is not None:
-            if not isinstance(session, client_session.ClientSession):
-                raise ValueError(
-                    f"'session' argument must be a ClientSession or None, not {type(session)}"
-                )
+        if session:
             # Don't call end_session.
             yield session
             return

test/asynchronous/test_session.py

@@ -877,6 +877,8 @@ async def test_nested_session_binding(self):
 
         session1 = self.client.start_session()
         session2 = self.client.start_session()
+        session1._materialize()
+        session2._materialize()
         try:
             self.listener.reset()
             # Uses implicit session

test/test_session.py

@@ -877,6 +877,8 @@ def test_nested_session_binding(self):
 
         session1 = self.client.start_session()
         session2 = self.client.start_session()
+        session1._materialize()
+        session2._materialize()
         try:
             self.listener.reset()
             # Uses implicit session