fix: Update Slack integration to fix message delivery issues (#6093)

lib/integrations/slack/incoming_message_builder.rb

@@ -22,13 +22,23 @@ class Integrations::Slack::IncomingMessageBuilder
   private
 
   def valid_event?
-    supported_event_type? && supported_event?
+    supported_event_type? && supported_event? && should_process_event?
   end
 
   def supported_event_type?
     SUPPORTED_EVENT_TYPES.include?(params[:type])
   end
 
+  # Discard all the subtype of a message event
+  # We are only considering the actual message sent by a Slack user
+  # Any reactions or messages sent by the bot will be ignored.
+  # https://api.slack.com/events/message#subtypes
+  def should_process_event?
+    return true if params[:type] != 'event_callback'
+
+    params[:event][:user].present? && params[:event][:subtype].blank?
+  end
+
   def supported_event?
     hook_verification? || SUPPORTED_EVENTS.include?(params[:event][:type])
   end

lib/integrations/slack/send_on_slack_service.rb

@@ -36,12 +36,13 @@ class Integrations::Slack::SendOnSlackService < Base::SendOnChannelService
     if conversation.identifier.present?
       "#{private_indicator}#{message.content}"
     else
-      "*Inbox: #{message.inbox.name} [#{message.inbox.inbox_type}]* \n\n #{message.content}"
+      "\n*Inbox:* #{message.inbox.name} (#{message.inbox.inbox_type})\n\n#{message.content}"
     end
   end
 
   def avatar_url(sender)
-    sender.try(:avatar_url) || "#{ENV.fetch('FRONTEND_URL', nil)}/admin/avatar_square.png"
+    sender_type = sender.instance_of?(Contact) ? 'contact' : 'user'
+    "#{ENV.fetch('FRONTEND_URL', nil)}/integrations/slack/#{sender_type}.png"
   end
 
   def send_message
@@ -86,7 +87,7 @@ class Integrations::Slack::SendOnSlackService < Base::SendOnChannelService
   end
 
   def sender_name(sender)
-    sender.try(:name) ? "#{sender_type(sender)}: #{sender.try(:name)}" : sender_type(sender)
+    sender.try(:name) ? "#{sender.try(:name)} (#{sender_type(sender)})" : sender_type(sender)
   end
 
   def sender_type(sender)