zulip package: Add unittest

As the first unittest, this creates a test directory and
abnd adds it tho the excluded pip package files.

There are two `tests` directories now, one in zulip_botserver and one in
zulip. This confuses the unittest runner, leading to failed test imports.
Therefore, we need to tell the package importer that there are multiple
tests directories, all of which should be considered for a search.

zulip/setup.py

@@ -74,7 +74,7 @@ setuptools_info = dict(
 try:
     from setuptools import setup, find_packages
     package_info.update(setuptools_info)
-    package_info['packages'] = find_packages()
+    package_info['packages'] = find_packages(exclude=['tests'])
 
 except ImportError:
     from distutils.core import setup

zulip/tests/__init__.py

@@ -0,0 +1,2 @@
+import pkgutil
+__path__ = pkgutil.extend_path(__path__, __name__)

zulip/tests/test_default_arguments.py

@@ -0,0 +1,45 @@
+from __future__ import absolute_import
+
+import argparse
+import os
+import six
+import unittest
+import zulip
+
+from unittest import TestCase
+
+if six.PY2:
+    from mock import patch
+else:
+    from unittest.mock import patch
+
+class TestDefaultArguments(TestCase):
+
+    def test_invalid_arguments(self):
+        parser = zulip.add_default_arguments(argparse.ArgumentParser(usage="lorem ipsum"))
+        with self.assertRaises(SystemExit) as cm, patch('sys.stderr', new=six.StringIO()) as mock_stderr:
+            parser.parse_args(['invalid argument'])
+        self.assertEqual(cm.exception.code, 2)
+        # Assert that invalid arguments exit with printing the full usage (non-standard behavior)
+        self.assertTrue(mock_stderr.getvalue().startswith("""usage: lorem ipsum
+
+optional arguments:
+  -h, --help            show this help message and exit
+
+Zulip API configuration:
+  --site ZULIP_SITE     Zulip server URI
+"""))
+
+    @patch('os.path.exists', return_value=False)
+    def test_config_path_with_tilde(self, mock_os_path_exists):
+        parser = zulip.add_default_arguments(argparse.ArgumentParser(usage="lorem ipsum"))
+        test_path = '~/zuliprc'
+        args = parser.parse_args(['--config-file', test_path])
+        with self.assertRaises(RuntimeError) as cm:
+            zulip.init_from_options(args)
+        expanded_test_path = os.path.abspath(os.path.expanduser(test_path))
+        self.assertEqual(str(cm.exception), 'api_key or email not specified and '
+                         'file {} does not exist'.format(expanded_test_path))
+
+if __name__ == '__main__':
+    unittest.main()

zulip_botserver/tests/__init__.py

@@ -0,0 +1,2 @@
+import pkgutil
+__path__ = pkgutil.extend_path(__path__, __name__)