Implemented async_unittest for writing tests for asynchronous code

Added logging call if main loop is exited unexpectedly

src/main.py

@@ -4,6 +4,8 @@
 from ui import MainWindow
 from common import get_app, get_loop, set_app_icon
 
+# call get_app and get_loop to have app and loop
+# be created in the globals of the common module
 app = get_app()
 loop = get_loop()
 set_app_icon()
@@ -13,6 +15,7 @@
     main_window.show()
     try:
         loop.run_until_complete(main_window.main_loop())
+        logging.warning("main loop exited unexpectedly")
         loop.run_forever()
     except RuntimeError as e:
         logging.exception(e)

test/async_unittest.py

@@ -0,0 +1,42 @@
+import asyncio
+from unittest import case, loader, mock, result, runner, signals, suite, util
+from unittest import *  # import everything that IS defined in __all__
+
+
+def AsyncMock(mock_func, *args, **kwargs):
+    '''
+    Returns an asynchronous function coroutine. The provided "mock_func"
+    argument is the function to be called when the coroutine is run.
+    All args and kwargs are passed to the mock when it is called.
+    '''
+    async def mock_coroutine(*args, **kwargs):
+        return mock_func(*args, **kwargs)
+
+    mock_coroutine.mock = mock_func
+    return mock_coroutine
+
+
+def AsyncMagicMock(*args, **kwargs):
+    '''
+    Returns an asynchronous function coroutine. The returned coroutine
+    contains a "mock" attribute, which is the MagicMock object to be called
+    when the coroutine is run. All args and kwargs are passed to the mock.
+    '''
+    return AsyncMock(mock.MagicMock(*args, **kwargs), *args, **kwargs)
+
+
+class AsyncTestCase(TestCase):
+    _loop = None
+
+    @property
+    def loop(self):
+        if self._loop is None:
+            self._loop = asyncio.get_event_loop()
+        return self._loop
+
+    @loop.setter
+    def loop(self, new_val):
+        self._loop = new_val
+
+    def run_async(self, coroutine):
+        return self.loop.run_until_complete(coroutine)

test/test_download.py

@@ -1,5 +1,5 @@
 import requests
-from unittest import TestCase, main, mock
+from async_unittest import AsyncTestCase, TestCase, mock, main
 from download import download_file, Download, DownloadTracker
 
 
@@ -155,7 +155,7 @@ def _call_download(self, test_path, test_url,
         test_download_file_no_session_provided
 
 
-class DownloadTrackerTest(TestCase):
+class DownloadTrackerTest(AsyncTestCase):
     download_tracker = None
     progress_bar = ProgressBarMock()
     executor = ExecutorMock()

test/test_ui.py

@@ -6,8 +6,8 @@
 import shutil
 import subprocess
 import sys
+from async_unittest import AsyncTestCase, TestCase, mock, main
 from PyQt5 import QtWidgets
-from unittest import TestCase, mock, main
 from util import namedtuple_from_mapping, get_platform
 
 config.setup_directories()
@@ -263,7 +263,7 @@ def subprocess_Popen_mock(args):
         self.assertFalse(mock_data['sys_exit_called'])
 
 
-class UiTest(TestCase):
+class UiTest(AsyncTestCase):
 
     def setUp(self):
         common.get_app()