Simplify emc test setup

tests/rpc/test_rpc_emc.py

@@ -2,7 +2,6 @@
 Unit test file for rpc/external_message_consumer.py
 """
 import asyncio
-import functools
 import logging
 from datetime import datetime, timezone
 from unittest.mock import MagicMock
@@ -302,19 +301,16 @@ async def test_emc_receive_messages_valid(default_conf, caplog, mocker):
     dp = DataProvider(default_conf, None, None, None)
     emc = ExternalMessageConsumer(default_conf, dp)
 
-    loop = asyncio.get_event_loop()
-    def change_running(emc): emc._running = not emc._running
-
     class TestChannel:
         async def recv(self, *args, **kwargs):
+            emc._running = False
             return {"type": "whitelist", "data": ["BTC/USDT"]}
 
         async def ping(self, *args, **kwargs):
             return asyncio.Future()
 
     try:
-        change_running(emc)
-        loop.call_soon(functools.partial(change_running, emc=emc))
+        emc._running = True
         await emc._receive_messages(TestChannel(), test_producer, lock)
 
         assert log_has_re(r"Received message of type `whitelist`.+", caplog)
@@ -349,19 +345,16 @@ async def test_emc_receive_messages_invalid(default_conf, caplog, mocker):
     dp = DataProvider(default_conf, None, None, None)
     emc = ExternalMessageConsumer(default_conf, dp)
 
-    loop = asyncio.get_event_loop()
-    def change_running(emc): emc._running = not emc._running
-
     class TestChannel:
         async def recv(self, *args, **kwargs):
+            emc._running = False
             return {"type": ["BTC/USDT"]}
 
         async def ping(self, *args, **kwargs):
             return asyncio.Future()
 
     try:
-        change_running(emc)
-        loop.call_soon(functools.partial(change_running, emc=emc))
+        emc._running = True
         await emc._receive_messages(TestChannel(), test_producer, lock)
 
         assert log_has_re(r"Invalid message from.+", caplog)
@@ -396,8 +389,8 @@ async def test_emc_receive_messages_timeout(default_conf, caplog, mocker):
     dp = DataProvider(default_conf, None, None, None)
     emc = ExternalMessageConsumer(default_conf, dp)
 
-    loop = asyncio.get_event_loop()
-    def change_running(emc): emc._running = not emc._running
+    def change_running():
+        emc._running = not emc._running
 
     class TestChannel:
         async def recv(self, *args, **kwargs):
@@ -407,8 +400,7 @@ async def test_emc_receive_messages_timeout(default_conf, caplog, mocker):
             return asyncio.Future()
 
     try:
-        change_running(emc)
-        loop.call_soon(functools.partial(change_running, emc=emc))
+        change_running()
 
         with pytest.raises(asyncio.TimeoutError):
             await emc._receive_messages(TestChannel(), test_producer, lock)
@@ -447,19 +439,16 @@ async def test_emc_receive_messages_handle_error(default_conf, caplog, mocker):
 
     emc.handle_producer_message = MagicMock(side_effect=Exception)
 
-    loop = asyncio.get_event_loop()
-    def change_running(emc): emc._running = not emc._running
-
     class TestChannel:
         async def recv(self, *args, **kwargs):
+            emc._running = False
             return {"type": "whitelist", "data": ["BTC/USDT"]}
 
         async def ping(self, *args, **kwargs):
             return asyncio.Future()
 
     try:
-        change_running(emc)
-        loop.call_soon(functools.partial(change_running, emc=emc))
+        emc._running = True
         await emc._receive_messages(TestChannel(), test_producer, lock)
 
         assert log_has_re(r"Error handling producer message.+", caplog)