Use our own AsyncMock

The one from unittest doesn't exist in Python 3.7.
Also consolidate a second async mock wrapper for code reuse.

tests/conftest.py

@@ -2,7 +2,6 @@
 import os.path
 
 import pytest
-from unittest.mock import AsyncMock
 import random
 import string
 import uuid
@@ -63,6 +62,7 @@
 from app.api.rest_api import RestApi
 
 from app import version
+from tests import AsyncMock
 
 DIR = os.path.dirname(os.path.abspath(__file__))
 CONFIG_DIR = os.path.join(DIR, '..', 'conf')

tests/services/test_planning_svc.py

@@ -11,6 +11,7 @@
 from app.objects.secondclass.c_fact import Fact
 from app.objects.secondclass.c_requirement import Requirement
 from app.utility.base_world import BaseWorld
+from tests import AsyncMock
 
 
 stop_bucket_exhaustion_params = [
@@ -69,13 +70,6 @@ def __init__(self, **kwargs):
     return PlannerStub(**kwargs)
 
 
-def async_wrapper(return_value):
-    """Creates an async method that returns a constant value for mocking purposes."""
-    async def wrap(*args, **kwargs):
-        return return_value
-    return wrap
-
-
 @pytest.fixture
 async def setup_planning_test(executor, ability, agent, operation, data_svc, event_svc, init_base_world):
     texecutor = executor(name='sh', platform='darwin', command='mkdir test', cleanup='rm -rf test')
@@ -355,9 +349,9 @@ async def test_trim_links(self, setup_planning_test, planning_svc):
             Fact(trait='a.b.e', value='3'),
         ]
 
-        operation.all_facts = async_wrapper(facts)
+        operation.all_facts = AsyncMock(return_value=facts)
         operation.planner = MagicMock()
-        planning_svc.load_module = async_wrapper(RequirementFake())
+        planning_svc.load_module = AsyncMock(return_value=RequirementFake())
         link.ability.requirements = [Requirement('fake_requirement', [{'fake': 'relationship'}])]
 
         trimmed_links = await planning_svc.trim_links(operation, [link], agent)