Close HTTP loop when connection task cancelled (#2245)

* Terminate loop when no transport exists

* Add log when closing HTTP loop because of shutdown

* Add unit test

tests/test_graceful_shutdown.py

@@ -0,0 +1,46 @@
+import asyncio
+import logging
+import time
+
+from collections import Counter
+from multiprocessing import Process
+
+import httpx
+
+
+PORT = 42101
+
+
+def test_no_exceptions_when_cancel_pending_request(app, caplog):
+    app.config.GRACEFUL_SHUTDOWN_TIMEOUT = 1
+
+    @app.get("/")
+    async def handler(request):
+        await asyncio.sleep(5)
+
+    @app.after_server_start
+    def shutdown(app, _):
+        time.sleep(0.2)
+        app.stop()
+
+    def ping():
+        time.sleep(0.1)
+        response = httpx.get("http://127.0.0.1:8000")
+        print(response.status_code)
+
+    p = Process(target=ping)
+    p.start()
+
+    with caplog.at_level(logging.INFO):
+        app.run()
+
+    p.kill()
+
+    counter = Counter([r[1] for r in caplog.record_tuples])
+
+    assert counter[logging.INFO] == 5
+    assert logging.ERROR not in counter
+    assert (
+        caplog.record_tuples[3][2]
+        == "Request: GET http://127.0.0.1:8000/ stopped. Transport is closed."
+    )

tests/test_signal_handlers.py

@@ -7,7 +7,6 @@ from unittest.mock import MagicMock
 
 import pytest
 
-from sanic_testing.reusable import ReusableClient
 from sanic_testing.testing import HOST, PORT
 
 from sanic.compat import ctrlc_workaround_for_windows
@@ -29,13 +28,9 @@ def set_loop(app, loop):
         signal.signal = mock
     else:
         loop.add_signal_handler = mock
-    print(">>>>>>>>>>>>>>>1", id(loop))
-    print(">>>>>>>>>>>>>>>1", loop.add_signal_handler)
 
 
 def after(app, loop):
-    print(">>>>>>>>>>>>>>>2", id(loop))
-    print(">>>>>>>>>>>>>>>2", loop.add_signal_handler)
     calledq.put(mock.called)
 
 
@@ -100,7 +95,7 @@ def test_windows_workaround():
         os.kill(os.getpid(), signal.SIGINT)
         await asyncio.sleep(0.2)
         assert app.is_stopping
-        assert app.stay_active_task.result() == None
+        assert app.stay_active_task.result() is None
         # Second Ctrl+C should raise
         with pytest.raises(KeyboardInterrupt):
             os.kill(os.getpid(), signal.SIGINT)