link_shortner bot : Add test for bad requests.

(This module now has 100% coverage.)

zulip_bots/zulip_bots/bots/link_shortener/fixtures/test_invalid_key.json

@@ -0,0 +1,27 @@
+{
+  "request": {
+    "api_url": "https://www.googleapis.com/urlshortener/v1/url",
+    "method": "POST",
+    "params": {
+      "key": "qwertyuiopx"
+    },
+    "json": {
+      "longUrl": "www.youtube.com/watch"
+    }
+  },
+  "response": {
+    "error":{
+      "errors":[
+        {
+          "reason":"keyInvalid"
+        }
+      ]
+    },
+    "code": 400,
+    "message": "Bad Request"
+  },
+  "response-headers": {
+    "status": 400,
+    "content-type": "application/json; charset=utf-8"
+  }
+}

zulip_bots/zulip_bots/bots/link_shortener/test_link_shortener.py

@@ -1,5 +1,8 @@
 from unittest.mock import patch
 from zulip_bots.test_lib import BotTestCase
+from zulip_bots.test_lib import StubBotHandler
+from zulip_bots.bots.link_shortener.link_shortener import LinkShortenerHandler
+
 
 class TestLinkShortenerBot(BotTestCase):
     bot_name = "link_shortener"
@@ -33,3 +36,10 @@ class TestLinkShortenerBot(BotTestCase):
             self._test('help',
                        ('Mention the link shortener bot in a conversation and then '
                         'enter any URLs you want to shorten in the body of the message.'))
+
+    def test_exception_when_api_key_is_invalid(self)-> None:
+        bot_test_instance = LinkShortenerHandler()
+        with self.mock_config_info({'key': 'qwertyuiopx'}):
+            with self.mock_http_conversation('test_invalid_key'):
+                with self.assertRaises(StubBotHandler.BotQuitException):
+                    bot_test_instance.initialize(StubBotHandler())