slack-bridge: Use WebClient to post message in Slack.

Author: rht

zulip/integrations/bridge_with_slack/run-slack-bridge

@@ -45,6 +45,9 @@ class SlackBridge:
         # slack-specific
         self.channel = self.slack_config["channel"]
         self.slack_client = slack.RTMClient(token=self.slack_config["token"], auto_reconnect=True)
+        # Spawn a non-websocket client for getting the users
+        # list and for posting messages in Slack.
+        self.slack_webclient = slack.WebClient(token=self.slack_config["token"])
 
     def wrap_slack_mention_with_bracket(self, zulip_msg: Dict[str, Any]) -> None:
         words = zulip_msg["content"].split(' ')
@@ -66,16 +69,14 @@ class SlackBridge:
                 self.wrap_slack_mention_with_bracket(msg)
                 slack_text = SLACK_MESSAGE_TEMPLATE.format(username=msg["sender_full_name"],
                                                            message=msg["content"])
-                self.slack_client.rtm_send_message(
-                    self.channel,
-                    slack_text,
+                self.slack_webclient.chat_postMessage(
+                    channel=self.channel,
+                    text=slack_text,
                 )
         return _zulip_to_slack
 
     def run_slack_listener(self) -> None:
-        # spawn a non-websocket client for getting the users list
-        _wc = slack.WebClient(token=self.slack_config["token"])
-        members = _wc.users_list()['members']
+        members = self.slack_webclient.users_list()['members']
         # See also https://api.slack.com/changelog/2017-09-the-one-about-usernames
         self.slack_id_to_name = {u["id"]: u["profile"].get("display_name", u["profile"]["real_name"]) for u in members}
         self.slack_name_to_id = {v: k for k, v in self.slack_id_to_name.items()}