fix: make streamable-http tests pass CI

Author: Jianke LIN

src/mcp/client/streamable_http.py

@@ -528,7 +528,7 @@ async def _handle_reconnection(
                 # Stream ended again without response - reconnect again (reset attempt counter)
                 logger.info("SSE stream disconnected, reconnecting...")
                 await self._handle_reconnection(ctx, reconnect_last_event_id, reconnect_retry_ms, 0)
-        except Exception as e:  # pragma: no cover
+        except Exception as e:
             logger.debug(f"Reconnection failed: {e}")
             # Try to reconnect again if we still have an event ID
             await self._handle_reconnection(ctx, last_event_id, retry_interval_ms, attempt + 1)

tests/client/test_streamable_http.py

@@ -100,6 +100,7 @@ async def test_sse_response_disconnect_before_any_event_id_fails_request() -> No
             await transport._handle_sse_response(response, ctx)
             message = await read_stream.receive()
 
+    assert isinstance(message, SessionMessage)
     assert isinstance(message.message, JSONRPCError)
     assert message.message.id == 1
     assert message.message.error.code == CONNECTION_CLOSED

tests/interaction/transports/test_hosting_resume.py

@@ -423,7 +423,7 @@ async def record_request(request: httpx.Request) -> None:
     ):
         manager_ref = manager
         with anyio.fail_after(5):  # pragma: no branch
-            async with (
+            async with (  # pragma: no branch
                 streamable_http_client(f"{BASE_URL}/mcp", http_client=http, terminate_on_close=False) as (r, w),
                 ClientSession(r, w) as session,
                 anyio.create_task_group() as tg,