Fixing tests in python 3.8.1. Filed issue with pytest-mock: pytest-de…

…v/pytest-mock#178

tests/transports/test_pool.py

@@ -1,4 +1,5 @@
 import asyncio
+import sys
 from asyncio import Future
 from concurrent.futures.thread import ThreadPoolExecutor
 from concurrent.futures import wait
@@ -215,9 +216,21 @@ async def test_checkout_checkin_threaded(
 
     Note that this will not grow the pool. See the doc string for TransportPool
     """
-    mocker.spy(redis_pool, "grow")
-    mocker.spy(redis_pool, "_create_transport")
-    mocker.spy(redis_pool, "_close_transport")
+
+    # mocker.spy in pytest-mock runs afoul of this change in 3.8.1
+    #    https://bugs.python.org/issue38857
+    # We therefore use mocker.spy for python 3.7, or the new AsyncMock in 3.8.
+    # See: https://github.com/pytest-dev/pytest-mock/issues/178
+    if sys.version_info >= (3, 8):
+        from unittest.mock import AsyncMock
+
+        redis_pool.grow = AsyncMock(wraps=redis_pool.grow)
+        redis_pool._create_transport = AsyncMock(wraps=redis_pool._create_transport)
+        redis_pool._close_transport = AsyncMock(wraps=redis_pool._close_transport)
+    else:
+        mocker.spy(redis_pool, "grow")
+        mocker.spy(redis_pool, "_create_transport")
+        mocker.spy(redis_pool, "_close_transport")
 
     async def _check_in_out():
         transport = await redis_pool.checkout()
@@ -247,9 +260,20 @@ async def test_checkout_checkin_asyncio(
 
     Unlike using threads, this should grow the pool
     """
-    mocker.spy(redis_pool, "grow")
-    mocker.spy(redis_pool, "_create_transport")
-    mocker.spy(redis_pool, "_close_transport")
+    # mocker.spy in pytest-mock runs afoul of this change in 3.8.1
+    #    https://bugs.python.org/issue38857
+    # We therefore use mocker.spy for python 3.7, or the new AsyncMock in 3.8
+    # See: https://github.com/pytest-dev/pytest-mock/issues/178
+    if sys.version_info >= (3, 8):
+        from unittest.mock import AsyncMock
+
+        redis_pool.grow = AsyncMock(wraps=redis_pool.grow)
+        redis_pool._create_transport = AsyncMock(wraps=redis_pool._create_transport)
+        redis_pool._close_transport = AsyncMock(wraps=redis_pool._close_transport)
+    else:
+        mocker.spy(redis_pool, "grow")
+        mocker.spy(redis_pool, "_create_transport")
+        mocker.spy(redis_pool, "_close_transport")
 
     async def _check_in_out():
         transport = await redis_pool.checkout()