From af16649725c2097df8e69e9538d3fe1fca410d6d Mon Sep 17 00:00:00 2001
From: Patrick Gingras <775.pg.12@gmail.com>
Date: Mon, 2 Nov 2020 22:34:09 -0500
Subject: [PATCH] sort imports and add some commentary to cancellederror test

---
 tests/test_websocket.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tests/test_websocket.py b/tests/test_websocket.py
index 3230832..26572e7 100644
--- a/tests/test_websocket.py
+++ b/tests/test_websocket.py
@@ -6,9 +6,10 @@ from urllib import parse
 
 import http_strategies
 from http_base import DaphneTestCase, DaphneTestingInstance
-from daphne.testing import BaseDaphneTestingInstance
 from hypothesis import given, settings
 
+from daphne.testing import BaseDaphneTestingInstance
+
 
 class TestWebsocket(DaphneTestCase):
     """
@@ -285,8 +286,10 @@ class TestWebsocket(DaphneTestCase):
 
 async def cancelling_application(scope, receive, send):
     import asyncio
+
     from twisted.internet import reactor
 
+    # Stop the server after a short delay so that the teardown is run.
     reactor.callLater(2, lambda: reactor.stop())
     await send({"type": "websocket.accept"})
     raise asyncio.CancelledError()
@@ -303,6 +306,11 @@ class CancellingTestingInstance(BaseDaphneTestingInstance):
     def process_teardown(self):
         import multiprocessing
 
+        # Get a hold of the enclosing DaphneProcess (we're currently running in
+        # the same process as the application).
         proc = multiprocessing.current_process()
+        # By now the (only) socket should have disconnected, and the
+        # application_checker should have run. If there are any connections
+        # still, it means that the application_checker did not clean them up.
         if proc.server.connections:
             raise ConnectionsNotEmpty()