FIX: chat channel sort order consistency in sidebar (#30180)

This change creates a shallow copy of the public message channels so we don't change the original array while sorting.

Without this change the publicMessageChannels getter cache gets invalidated and cached again with the sorted channels array instead, which causes a bug where the sidebar channel list sorting order is updated by activity when user interacts with the chat drawer.

plugins/chat/assets/javascripts/discourse/components/channels-list-public.gjs

@@ -34,9 +34,7 @@ export default class ChannelsListPublic extends Component {
   }
 
   get channelList() {
-    return this.args.sortByActivity === true
-      ? this.chatChannelsManager.publicMessageChannelsByActivity
-      : this.chatChannelsManager.publicMessageChannels;
+    return this.chatChannelsManager.publicMessageChannelsByActivity;
   }
 
   @action

plugins/chat/assets/javascripts/discourse/components/chat/drawer-routes/channels.gjs

@@ -22,7 +22,7 @@ export default class ChatDrawerRoutesChannels extends Component {
 
       {{#if this.chatStateManager.isDrawerExpanded}}
         <div class="chat-drawer-content">
-          <ChannelsListPublic @sortByActivity={{true}} />
+          <ChannelsListPublic />
         </div>
 
         <ChatFooter />

plugins/chat/assets/javascripts/discourse/components/chat/routes/channels.gjs

@@ -17,7 +17,7 @@ export default class ChatRoutesChannels extends Component {
         </navbar.Actions>
       </Navbar>
 
-      <ChannelsListPublic @sortByActivity={{true}} />
+      <ChannelsListPublic />
     </div>
   </template>
 }

plugins/chat/assets/javascripts/discourse/services/chat-channels-manager.js

@@ -136,7 +136,7 @@ export default class ChatChannelsManager extends Service {
   }
 
   get publicMessageChannelsByActivity() {
-    return this.#sortChannelsByActivity(this.publicMessageChannels);
+    return this.#sortChannelsByActivity([...this.publicMessageChannels]);
   }
 
   @cached

plugins/chat/spec/system/list_channels/sidebar_spec.rb

@@ -4,6 +4,7 @@ RSpec.describe "List channels | sidebar", type: :system do
   fab!(:current_user) { Fabricate(:user) }
 
   let(:chat) { PageObjects::Pages::Chat.new }
+  let(:drawer_page) { PageObjects::Pages::ChatDrawer.new }
 
   before do
     chat_system_bootstrap
@@ -72,6 +73,24 @@ RSpec.describe "List channels | sidebar", type: :system do
           ".channel-#{channel_1.id}",
         )
       end
+
+      it "does not change sorting order when using drawer" do
+        Fabricate(:chat_message, chat_channel: channel_1)
+        visit("/")
+
+        expect(page.find("#sidebar-section-content-chat-channels li:nth-child(1)")).to have_css(
+          ".channel-#{channel_2.id}",
+        )
+
+        drawer_page.visit_index
+        drawer_page.click_channels
+
+        expect(drawer_page).to have_channel_at_position(channel_1, 1)
+
+        expect(page.find("#sidebar-section-content-chat-channels li:nth-child(1)")).to have_css(
+          ".channel-#{channel_2.id}",
+        )
+      end
     end
 
     context "when direct message channels" do