Update test_jhu to handle asyncio

- Move test fixtures into tests/fixtures.py
- Update test fixtures to mock aiohttp.ClientSession.get, instead of requests.get
- Add a context manager to replace the global httputils.client_session with an AsyncMock
- Misc. cleanup

Author: james-gray

tests/fixtures.py

@@ -0,0 +1,89 @@
+import datetime
+import os
+from contextlib import asynccontextmanager
+from unittest import mock
+
+from app.utils import httputils
+
+
+class DateTimeStrpTime:
+    """Returns instance of `DateTimeStrpTime`
+    when calling `app.services.location.jhu.datetime.trptime(date, '%m/%d/%y').isoformat()`.
+    """
+
+    def __init__(self, date, strformat):
+        self.date = date
+        self.strformat = strformat
+
+    def isoformat(self):
+        return datetime.datetime.strptime(self.date, self.strformat).isoformat()
+
+
+class FakeRequestsGetResponse:
+    """Fake instance of a response from `aiohttp.ClientSession.get`.
+    """
+
+    def __init__(self, url, filename, state):
+        self.url = url
+        self.filename = filename
+        self.state = state
+
+    async def text(self):
+        return self.read_file(self.state)
+
+    def read_file(self, state):
+        """
+        Mock HTTP GET-method and return text from file
+        """
+        state = state.lower()
+
+        # Determine filepath.
+        filepath = os.path.join(os.path.dirname(__file__), "example_data/{}.csv".format(state))
+
+        # Return fake response.
+        print("Try to read {}".format(filepath))
+        with open(filepath, "r") as file:
+            return file.read()
+
+
+@asynccontextmanager
+async def mock_client_session():
+    """Context manager that replaces the global client_session with an AsyncMock instance.
+
+    :Example:
+
+    >>> async with mock_client_session() as mocked_client_session:
+    >>>     mocked_client_session.get = mocked_session_get
+    >>>     # test code...
+
+    """
+
+    httputils.client_session = mocked_client_session = mock.AsyncMock()
+    try:
+        yield mocked_client_session
+    finally:
+        del httputils.client_session
+
+
+@asynccontextmanager
+async def mocked_session_get(*args, **kwargs):
+    """Mock response from client_session.get.
+    """
+
+    url = args[0]
+    filename = url.split("/")[-1]
+
+    # clean up for id token (e.g. Deaths)
+    state = filename.split("-")[-1].replace(".csv", "").lower().capitalize()
+
+    yield FakeRequestsGetResponse(url, filename, state)
+
+
+def mocked_strptime_isoformat(*args, **kwargs):
+    """Mock return value from datetime.strptime().isoformat().
+    """
+
+    date = args[0]
+    strformat = args[1]
+
+    return DateTimeStrpTime(date, strformat)

tests/test_jhu.py

@@ -6,81 +6,26 @@
 import app
 from app import location
 from app.services.location import jhu
-from app.utils import date
+from tests.fixtures import mock_client_session
+from tests.fixtures import mocked_session_get
+from tests.fixtures import mocked_strptime_isoformat
 
 DATETIME_STRING = "2020-03-17T10:23:22.505550"
 
 
-def mocked_requests_get(*args, **kwargs):
-    class FakeRequestsGetResponse:
-        """
-        Returns instance of `FakeRequestsGetResponse`
-        when calling `app.services.location.jhu.requests.get()`
-        """
-
-        def __init__(self, url, filename, state):
-            self.url = url
-            self.filename = filename
-            self.state = state
-            self.text = self.read_file(self.state)
-
-        def read_file(self, state):
-            """
-            Mock HTTP GET-method and return text from file
-            """
-            state = state.lower()
-
-            # Determine filepath.
-            filepath = "tests/example_data/{}.csv".format(state)
-
-            # Return fake response.
-            print("Try to read {}".format(filepath))
-            with open(filepath, "r") as file:
-                return file.read()
-
-    # get url from `request.get`
-    url = args[0]
-
-    # get filename from url
-    filename = url.split("/")[-1]
-
-    # clean up for id token (e.g. Deaths)
-    state = filename.split("-")[-1].replace(".csv", "").lower().capitalize()
-
-    return FakeRequestsGetResponse(url, filename, state)
-
-
-def mocked_strptime_isoformat(*args, **kwargs):
-    class DateTimeStrpTime:
-        """
-        Returns instance of `DateTimeStrpTime`
-        when calling `app.services.location.jhu.datetime.trptime(date, '%m/%d/%y').isoformat()`
-        """
-
-        def __init__(self, date, strformat):
-            self.date = date
-            self.strformat = strformat
-
-        def isoformat(self):
-            return datetime.datetime.strptime(self.date, self.strformat).isoformat()
-
-    date = args[0]
-    strformat = args[1]
-
-    return DateTimeStrpTime(date, strformat)
-
-
+@pytest.mark.asyncio
 @mock.patch("app.services.location.jhu.datetime")
-@mock.patch("app.services.location.jhu.requests.get", side_effect=mocked_requests_get)
-def test_get_locations(mock_request_get, mock_datetime):
-    # mock app.services.location.jhu.datetime.utcnow().isoformat()
+async def test_get_locations(mock_datetime):
     mock_datetime.utcnow.return_value.isoformat.return_value = DATETIME_STRING
     mock_datetime.strptime.side_effect = mocked_strptime_isoformat
 
-    output = jhu.get_locations()
-    assert isinstance(output, list)
-    assert isinstance(output[0], location.Location)
+    async with mock_client_session() as mocked_client_session:
+        mocked_client_session.get = mocked_session_get
+        output = await jhu.get_locations()
+
+        assert isinstance(output, list)
+        assert isinstance(output[0], location.Location)
 
-    # `jhu.get_locations()` creates id based on confirmed list
-    location_confirmed = jhu.get_category("confirmed")
-    assert len(output) == len(location_confirmed["locations"])
+        # `jhu.get_locations()` creates id based on confirmed list
+        location_confirmed = await jhu.get_category("confirmed")
+        assert len(output) == len(location_confirmed["locations"])