Extract test_file_utils.py.

This isolates all the code that depends on our current
directory structure, and it de-clutters test_lib.py a bit.

zulip_bots/zulip_bots/test_file_utils.py

@@ -0,0 +1,35 @@
+import json
+import os
+
+from importlib import import_module
+
+from typing import Any, Dict
+
+'''
+This module helps us find files in the bots directory.  Our
+directory structure is currently:
+
+    zulip_bots/zulip_bots/bots/
+        <bot name>/
+            <bot name>.py
+            fixtures/
+'''
+
+def get_bot_message_handler(bot_name):
+    # type: (str) -> Any
+    # message_handler is of type 'Any', since it can contain any bot's
+    # handler class. Eventually, we want bot's handler classes to
+    # inherit from a common prototype specifying the handle_message
+    # function.
+    lib_module = import_module('zulip_bots.bots.{bot}.{bot}'.format(bot=bot_name))  # type: Any
+    return lib_module.handler_class()
+
+def read_bot_fixture_data(bot_name, test_name):
+    # type: (str, str) -> Dict[str, Any]
+    base_path = os.path.realpath(os.path.join(os.path.dirname(
+        os.path.abspath(__file__)), 'bots', bot_name, 'fixtures'))
+    http_data_path = os.path.join(base_path, '{}.json'.format(test_name))
+    with open(http_data_path) as f:
+        content = f.read()
+    http_data = json.loads(content)
+    return http_data

zulip_bots/zulip_bots/test_lib.py

@@ -1,10 +1,7 @@
-import json
 import mock
-import os
 
 from mock import patch
 
-from importlib import import_module
 from unittest import TestCase
 
 from typing import List, Dict, Any, Tuple
@@ -19,6 +16,11 @@ from zulip_bots.simple_lib import (
     SimpleMessageServer,
 )
 
+from zulip_bots.test_file_utils import (
+    get_bot_message_handler,
+    read_bot_fixture_data,
+)
+
 class StubBotHandler:
     def __init__(self):
         # type: () -> None
@@ -169,22 +171,3 @@ class StubBotTestCase(TestCase):
     def mock_config_info(self, config_info):
         # type: (Dict[str, str]) -> Any
         return patch('zulip_bots.test_lib.StubBotHandler.get_config_info', return_value=config_info)
-
-def get_bot_message_handler(bot_name):
-    # type: (str) -> Any
-    # message_handler is of type 'Any', since it can contain any bot's
-    # handler class. Eventually, we want bot's handler classes to
-    # inherit from a common prototype specifying the handle_message
-    # function.
-    lib_module = import_module('zulip_bots.bots.{bot}.{bot}'.format(bot=bot_name))  # type: Any
-    return lib_module.handler_class()
-
-def read_bot_fixture_data(bot_name, test_name):
-    # type: (str, str) -> Dict[str, Any]
-    base_path = os.path.realpath(os.path.join(os.path.dirname(
-        os.path.abspath(__file__)), 'bots', bot_name, 'fixtures'))
-    http_data_path = os.path.join(base_path, '{}.json'.format(test_name))
-    with open(http_data_path) as f:
-        content = f.read()
-    http_data = json.loads(content)
-    return http_data