make graphql_ws test less timing-sensitive. (#2785)

* make graphql_ws test less timing-sensitive.

* Mark a timing dependent test as flaky

tests/websockets/test_graphql_transport_ws.py

@@ -787,6 +787,9 @@ async def test_rejects_connection_params_not_unset(ws_raw: WebSocketClient):
     ws.assert_reason("Invalid connection init payload")
 
 
+# timings can sometimes fail currently.  Until this test is rewritten when
+# generator based subscriptions are implemented, mark it as flaky
+@pytest.mark.flaky
 async def test_subsciption_cancel_finalization_delay(ws: WebSocketClient):
     # Test that when we cancel a subscription, the websocket isn't blocked
     # while some complex finalization takes place.

tests/websockets/test_graphql_ws.py

@@ -119,13 +119,17 @@ async def test_sends_keep_alive(aiohttp_app_client: HttpClient):
         response = await ws.receive_json()
         assert response["type"] == GQL_CONNECTION_ACK
 
-        response = await ws.receive_json()
-        assert response["type"] == GQL_CONNECTION_KEEP_ALIVE
-
-        response = await ws.receive_json()
-        assert response["type"] == GQL_CONNECTION_KEEP_ALIVE
+        # we can't be sure how many keep-alives exactly we
+        # get but they should be more than one.
+        keepalive_count = 0
+        while True:
+            response = await ws.receive_json()
+            if response["type"] == GQL_CONNECTION_KEEP_ALIVE:
+                keepalive_count += 1
+            else:
+                break
+        assert keepalive_count >= 1
 
-        response = await ws.receive_json()
         assert response["type"] == GQL_DATA
         assert response["id"] == "demo"
         assert response["payload"]["data"] == {"echo": "Hi"}