DEV: Move discourse-chat to the core repo. (#18776)

As part of this move, we are also renaming `discourse-chat` to `chat`.

plugins/chat/lib/discourse_dev/message.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require "discourse_dev/record"
+require "faker"
+
+module DiscourseDev
+  class Message < Record
+    def initialize
+      super(::ChatMessage, 200)
+    end
+
+    def data
+      if Faker::Boolean.boolean(true_ratio: 0.5)
+        channel = ::ChatChannel.where(chatable_type: "DirectMessageChannel").order("RANDOM()").first
+        channel.user_chat_channel_memberships.update_all(following: true)
+        user = channel.chatable.users.order("RANDOM()").first
+      else
+        membership = ::UserChatChannelMembership.order("RANDOM()").first
+        channel = membership.chat_channel
+        user = membership.user
+      end
+
+      { user: user, content: Faker::Lorem.paragraph, chat_channel: channel }
+    end
+
+    def create!
+      Chat::ChatMessageCreator.create(data)
+    end
+  end
+end