mypy: Add annotations for Link Shortener Bot.

Based on work started by @skunkmb.

tools/run-mypy

@@ -49,6 +49,8 @@ force_include = [
     "zulip_bots/zulip_bots/bots/help/test_help.py",
     "zulip_bots/zulip_bots/bots/incrementor/incrementor.py",
     "zulip_bots/zulip_bots/bots/incrementor/test_incrementor.py",
+    "zulip_bots/zulip_bots/bots/link_shortener/link_shortener.py",
+    "zulip_bots/zulip_bots/bots/link_shortener/test_link_shortener.py",
     "zulip_bots/zulip_bots/bots/virtual_fs/virtual_fs.py",
     "zulip_bots/zulip_bots/bots/virtual_fs/test_virtual_fs.py",
     "zulip_bots/zulip_bots/bots/weather/test_weather.py",

zulip_bots/zulip_bots/bots/link_shortener/link_shortener.py

@@ -1,21 +1,23 @@
 import re
 import requests
 
+from typing import Any, Dict
+
 class LinkShortenerHandler(object):
     '''A Zulip bot that will shorten URLs ("links") in a conversation using the
     goo.gl URL shortener.
     '''
 
-    def usage(self):
+    def usage(self) -> str:
         return (
             'Mention the link shortener bot in a conversation and then enter '
             'any URLs you want to shorten in the body of the message. \n\n'
             '`key` must be set in `link_shortener.conf`.')
 
-    def initialize(self, bot_handler):
+    def initialize(self, bot_handler: Any) -> None:
         self.config_info = bot_handler.get_config_info('link_shortener')
 
-    def handle_message(self, message, bot_handler):
+    def handle_message(self, message: Dict[str, str], bot_handler: Any) -> None:
         REGEX_STR = (
             '('
             '(?:http|https):\/\/'  # This allows for the HTTP or HTTPS
@@ -58,7 +60,7 @@ class LinkShortenerHandler(object):
 
         bot_handler.send_reply(message, final_response)
 
-    def shorten_link(self, long_url):
+    def shorten_link(self, long_url: str) -> str:
         '''Shortens a link using goo.gl Link Shortener and returns it, or
         returns an empty string if something goes wrong.
 

zulip_bots/zulip_bots/bots/link_shortener/test_link_shortener.py

@@ -3,18 +3,18 @@ from zulip_bots.test_lib import StubBotTestCase
 class TestLinkShortenerBot(StubBotTestCase):
     bot_name = "link_shortener"
 
-    def _test(self, message, response):
+    def _test(self, message: str, response: str) -> None:
         with self.mock_config_info({'key': 'qwertyuiop'}):
             self.verify_reply(message, response)
 
-    def test_bot(self):
+    def test_bot(self) -> None:
         message = 'Shorten https://www.github.com/zulip/zulip please.'
         response = 'https://www.github.com/zulip/zulip: https://goo.gl/6uoWKb'
 
         with self.mock_http_conversation('test_normal'):
             self._test(message, response)
 
-    def test_bot_empty(self):
+    def test_bot_empty(self) -> None:
         message = 'Shorten nothing please.'
         response = 'No links found. Send "help" to see usage instructions.'
 
@@ -23,7 +23,7 @@ class TestLinkShortenerBot(StubBotTestCase):
         # requests.
         self._test(message, response)
 
-    def test_bot_help(self):
+    def test_bot_help(self) -> None:
         message = 'help'
         response = ('Mention the link shortener bot in a conversation and then '
                     'enter any URLs you want to shorten in the body of the message.')