✅ management: add tests for runner module

also:
exclude __name__ == '__main__' clause from coverage report

.coveragerc

@@ -1,3 +1,8 @@
 [run]
 source = localshop
 omit = *migrations*, localshop/settings.py
+
+[report]
+exclude_lines =
+    pragma: no cover
+    if __name__ == .__main__.:

tests/management/test_runner.py

@@ -0,0 +1,43 @@
+import copy
+import os
+
+import mock
+
+from django.test import TestCase
+from localshop.runner import main
+
+manage_instance = mock.MagicMock()
+manage_mock = mock.MagicMock(return_value=manage_instance)
+
+
+@mock.patch('django.core.management.ManagementUtility', manage_mock)
+class TestRunner(TestCase):
+
+    def tearDown(self):
+        manage_instance.reset_mock()
+        manage_mock.reset_mock()
+
+    @mock.patch('sys.argv', [])
+    def test_no_args_passed_manager(self):
+        main()
+        manage_mock.assert_called_once_with([])
+        manage_instance.execute.assert_called_once_with()
+
+    @mock.patch('sys.argv', ['init', '--no-superuser'])
+    def test_args_passed_manager(self):
+        main()
+        manage_mock.assert_called_once_with(['init', '--no-superuser'])
+        manage_instance.execute.assert_called_once_with()
+
+    def test_set_env_defaults(self):
+        # backup and remove global environment vars
+        oldenv = copy.copy(os.environ)
+        del os.environ['DJANGO_SETTINGS_MODULE']
+        del os.environ['DJANGO_CONFIGURATION']
+        main()
+        self.assertIn('DJANGO_SETTINGS_MODULE', os.environ)
+        self.assertIn('DJANGO_CONFIGURATION', os.environ)
+        self.assertEqual(os.environ['DJANGO_SETTINGS_MODULE'],
+                         'localshop.settings')
+        self.assertEqual(os.environ['DJANGO_CONFIGURATION'], 'Localshop')
+        os.environ = oldenv