bot events: Prevent duplicate add-bot notifications.

We don't need `do_create_user` to send a partial
event here for bots.  The only caller to `do_create_user`
that actually creates bots (apart from some tests that
just need data setup) is `add_bot_backend`, which
sends the more complete event including bot "extras"
like service info.

The modified event tests show the simplification
here (2 events instead of 3).

Also, the bot tests now use tuple unpacking, which
will force a ValueError if we duplicate events
again.

zerver/lib/actions.py

@@ -523,10 +523,10 @@ def do_create_user(email: str, password: Optional[str], realm: Realm, full_name:
     if settings.BILLING_ENABLED:
         update_license_ledger_if_needed(user_profile.realm, event_time)
 
+    # Note that for bots, the caller will send an additional event
+    # with bot-specific info like services.
     notify_created_user(user_profile)
-    if bot_type:
-        notify_created_bot(user_profile)
-    else:
+    if bot_type is None:
         process_new_human_user(user_profile, prereg_user=prereg_user,
                                newsletter_data=newsletter_data,
                                default_stream_groups=default_stream_groups,

zerver/tests/test_bots.py

@@ -160,7 +160,11 @@ class BotTest(ZulipTestCase, UploadSerializeMixin):
         email = 'hambot-bot@zulip.testserver'
         bot = self.get_bot_user(email)
 
-        event = [e for e in events if e['event']['type'] == 'realm_bot'][0]
+        (event,) = [
+            e for e in events
+            if e['event']['type'] == 'realm_bot'
+        ]
+
         self.assertEqual(
             dict(
                 type='realm_bot',
@@ -291,7 +295,10 @@ class BotTest(ZulipTestCase, UploadSerializeMixin):
         email = 'hambot-bot@zulip.testserver'
         bot = self.get_bot_user(email)
 
-        event = [e for e in events if e['event']['type'] == 'realm_bot'][0]
+        (event,) = [
+            e for e in events
+            if e['event']['type'] == 'realm_bot'
+        ]
         self.assertEqual(
             dict(
                 type='realm_bot',
@@ -390,7 +397,10 @@ class BotTest(ZulipTestCase, UploadSerializeMixin):
         assert(profile.default_sending_stream is not None)
         self.assertEqual(profile.default_sending_stream.name, 'Denmark')
 
-        event = [e for e in events if e['event']['type'] == 'realm_bot'][0]
+        (event,) = [
+            e for e in events
+            if e['event']['type'] == 'realm_bot'
+        ]
         self.assertEqual(
             dict(
                 type='realm_bot',
@@ -462,7 +472,10 @@ class BotTest(ZulipTestCase, UploadSerializeMixin):
         assert(bot_profile.default_events_register_stream is not None)
         self.assertEqual(bot_profile.default_events_register_stream.name, 'Denmark')
 
-        event = [e for e in events if e['event']['type'] == 'realm_bot'][0]
+        (event,) = [
+            e for e in events
+            if e['event']['type'] == 'realm_bot'
+        ]
         self.assertEqual(
             dict(
                 type='realm_bot',

zerver/tests/test_events.py

@@ -2108,7 +2108,7 @@ class EventsRegisterTest(ZulipTestCase):
                 ])),
             ])
         action = lambda: self.create_bot('test')
-        events = self.do_test(action, num_events=3)
+        events = self.do_test(action, num_events=2)
         error = get_bot_created_checker(bot_type="GENERIC_BOT")('events[1]', events[1])
         self.assert_on_error(error)
 
@@ -2117,10 +2117,10 @@ class EventsRegisterTest(ZulipTestCase):
                                          payload_url=ujson.dumps('https://foo.bar.com'),
                                          interface_type=Service.GENERIC,
                                          bot_type=UserProfile.OUTGOING_WEBHOOK_BOT)
-        events = self.do_test(action, num_events=3)
+        events = self.do_test(action, num_events=2)
         # The third event is the second call of notify_created_bot, which contains additional
         # data for services (in contrast to the first call).
-        error = get_bot_created_checker(bot_type="OUTGOING_WEBHOOK_BOT")('events[2]', events[2])
+        error = get_bot_created_checker(bot_type="OUTGOING_WEBHOOK_BOT")('events[1]', events[1])
         self.assert_on_error(error)
 
         action = lambda: self.create_bot('test_embedded',
@@ -2128,8 +2128,8 @@ class EventsRegisterTest(ZulipTestCase):
                                          service_name='helloworld',
                                          config_data=ujson.dumps({'foo': 'bar'}),
                                          bot_type=UserProfile.EMBEDDED_BOT)
-        events = self.do_test(action, num_events=3)
-        error = get_bot_created_checker(bot_type="EMBEDDED_BOT")('events[2]', events[2])
+        events = self.do_test(action, num_events=2)
+        error = get_bot_created_checker(bot_type="EMBEDDED_BOT")('events[1]', events[1])
         self.assert_on_error(error)
 
     def test_change_bot_full_name(self) -> None: