FEATURE: enable_public_channels site setting (#22565)

`SiteSetting.enable_public_channels` allows site admin to decide if public channels are available at all. There's no distinction between admins or not as we expect admins to create private category channels if they want to limit usage.

plugins/chat/spec/system/browse_page_spec.rb

@@ -20,6 +20,15 @@ RSpec.describe "Browse page", type: :system do
     end
   end
 
+  context "when public channels are disabled" do
+    before { SiteSetting.enable_public_channels = false }
+
+    it "redirects to homepage" do
+      visit("/chat/browse") # no page object here as we actually don't load it
+      expect(page).to have_current_path("/latest")
+    end
+  end
+
   context "when user has chat enabled" do
     context "when visiting browse page" do
       it "defaults to open filer" do

plugins/chat/spec/system/new_message_spec.rb

@@ -20,6 +20,47 @@ RSpec.describe "New message", type: :system do
     expect(chat_page.message_creator).to be_opened
   end
 
+  context "when public channels are disabled" do
+    fab!(:channel_1) { Fabricate(:chat_channel) }
+
+    before do
+      SiteSetting.enable_public_channels = false
+      channel_1.add(current_user)
+    end
+
+    it "doesn’t list public channels" do
+      visit("/")
+      chat_page.open_new_message
+
+      expect(chat_page.message_creator).to be_not_listing(channel_1)
+    end
+
+    it "has a correct placeholder" do
+      visit("/")
+      chat_page.open_new_message
+
+      expect(chat_page.message_creator.input["placeholder"]).to eq(
+        I18n.t("js.chat.new_message_modal.default_user_search_placeholder"),
+      )
+    end
+  end
+
+  context "when public channels are disabled and user can't create direct message" do
+    fab!(:current_user) { Fabricate(:user) }
+
+    before do
+      SiteSetting.enable_public_channels = false
+      SiteSetting.direct_message_enabled_groups = Group::AUTO_GROUPS[:staff]
+    end
+
+    it "doesn’t list public channels" do
+      visit("/")
+      chat_page.open_new_message(ensure_open: false)
+
+      expect(chat_page.message_creator).to be_closed
+    end
+  end
+
   context "when the the content is not filtered" do
     fab!(:channel_1) { Fabricate(:chat_channel) }
     fab!(:channel_2) { Fabricate(:chat_channel) }

plugins/chat/spec/system/page_objects/chat/chat.rb

@@ -29,9 +29,9 @@ module PageObjects
         visit("/chat")
       end
 
-      def open_new_message
+      def open_new_message(ensure_open: true)
         send_keys([PLATFORM_KEY_MODIFIER, "k"])
-        find(".chat-modal-new-message")
+        find(".chat-modal-new-message") if ensure_open
       end
 
       def has_drawer?(channel_id: nil, expanded: true)

plugins/chat/spec/system/page_objects/chat/components/message_creator.rb

@@ -24,6 +24,10 @@ module PageObjects
           page.has_css?(SELECTOR)
         end
 
+        def closed?
+          page.has_no_css?(SELECTOR)
+        end
+
         def enter_shortcut
           input.send_keys(:enter)
         end

plugins/chat/spec/system/page_objects/sidebar/sidebar.rb

@@ -3,19 +3,27 @@
 module PageObjects
   module Pages
     class Sidebar < PageObjects::Pages::Base
+      PUBLIC_CHANNELS_SECTION_SELECTOR = ".sidebar-section[data-section-name='chat-channels']"
+      DM_CHANNELS_SECTION_SELECTOR = ".sidebar-section[data-section-name='chat-dms']"
+
+      def has_no_public_channels_section?
+        has_no_css?(PUBLIC_CHANNELS_SECTION_SELECTOR)
+      end
+
       def channels_section
-        find(".sidebar-section[data-section-name='chat-channels']")
+        find(PUBLIC_CHANNELS_SECTION_SELECTOR)
+      end
+
+      def channels_section
+        find(PUBLIC_CHANNELS_SECTION_SELECTOR)
       end
 
       def dms_section
-        find(".sidebar-section[data-section-name='chat-dms']")
+        find(DM_CHANNELS_SECTION_SELECTOR)
       end
 
       def open_browse
-        find(
-          ".sidebar-section[data-section-name='chat-channels'] .sidebar-section-header-button",
-          visible: false,
-        ).click
+        channels_section.find(".sidebar-section-header-button", visible: false).click
       end
 
       def open_channel(channel)

plugins/chat/spec/system/sidebars_spec.rb

@@ -8,6 +8,7 @@ RSpec.describe "Navigation", type: :system do
   fab!(:category_channel) { Fabricate(:category_channel) }
   fab!(:category_channel_2) { Fabricate(:category_channel) }
   let(:chat_page) { PageObjects::Pages::Chat.new }
+  let(:sidebar_page) { PageObjects::Pages::Sidebar.new }
 
   before do
     chat_system_bootstrap(user, [category_channel, category_channel_2])
@@ -40,6 +41,16 @@ RSpec.describe "Navigation", type: :system do
         expect(page).to have_no_css("#d-sidebar")
       end
     end
+
+    context "when public channels are disabled" do
+      before { SiteSetting.enable_public_channels = false }
+
+      it "has public channels section" do
+        visit("/")
+
+        expect(sidebar_page).to have_no_public_channels_section
+      end
+    end
   end
 
   context "when visiting on mobile" do