FEATURE: Initial admin sidebar navigation (#24789)

This is v0 of admin sidebar navigation, which moves
all of the top-level admin nav from the top of the page
into a sidebar. This is hidden behind a enable_admin_sidebar_navigation
site setting, and is opt-in for now.

This sidebar is dynamically shown whenever the user enters an
admin route in the UI, and is hidden and replaced with either
the:

* Main forum sidebar
* Chat sidebar

Depending on where they navigate to. For now, custom sections
are not supported in the admin sidebar.

This commit removes the experimental admin sidebar generation rake
task but keeps the experimental sidebar UI for now for further
testing; it just uses the real nav as the default now.

spec/system/admin_revamp_sidebar_navigation_spec.rb

@@ -2,18 +2,29 @@
 
 describe "Admin Revamp | Sidebar Navigation", type: :system do
   fab!(:admin)
-  let(:sidebar_page) { PageObjects::Components::NavigationMenu::Sidebar.new }
+  let(:sidebar) { PageObjects::Components::NavigationMenu::Sidebar.new }
 
   before do
-    SiteSetting.enable_experimental_admin_ui_groups = Group::AUTO_GROUPS[:staff]
-    SidebarSection.find_by(section_type: "community").reset_community!
+    SiteSetting.enable_admin_sidebar_navigation = true
     sign_in(admin)
   end
 
-  it "navigates to the admin revamp from the sidebar" do
+  it "shows the sidebar when navigating to an admin route and hides it when leaving" do
     visit("/latest")
-    sidebar_page.click_section_link("Admin Revamp")
-    expect(page).to have_content("Lobby")
-    expect(page).to have_content("Legacy Admin")
+    sidebar.click_link_in_section("community", "admin")
+    expect(page).to have_current_path("/admin")
+    expect(sidebar).to be_visible
+    expect(page).to have_no_css(".admin-main-nav")
+    sidebar.click_link_in_section("admin-nav-section-root", "back_to_forum")
+    expect(page).to have_current_path("/latest")
+    expect(sidebar).to have_no_section("admin-nav-section-root")
+  end
+
+  it "does not show the admin sidebar if the setting is disabled" do
+    SiteSetting.enable_admin_sidebar_navigation = false
+    visit("/latest")
+    sidebar.click_link_in_section("community", "admin")
+    expect(page).to have_current_path("/admin")
+    expect(sidebar).to have_no_section("admin-nav-section-root")
   end
 end

spec/system/page_objects/components/navigation_menu/base.rb

@@ -4,16 +4,34 @@ module PageObjects
   module Components
     module NavigationMenu
       class Base < PageObjects::Components::Base
-        def community_section
-          find(".sidebar-section[data-section-name='community']")
+        SIDEBAR_SECTION_LINK_SELECTOR = "sidebar-section-link"
+
+        def visible?
+          has_css?("#d-sidebar.sidebar-container")
         end
 
-        SIDEBAR_SECTION_LINK_SELECTOR = "sidebar-section-link"
+        def hidden?
+          has_no_css?("#d-sidebar.sidebar-container")
+        end
+
+        def community_section
+          find_section("community")
+        end
+
+        def find_section(name)
+          find(".sidebar-section[data-section-name='#{name}']")
+        end
 
         def click_section_link(name)
           find(".#{SIDEBAR_SECTION_LINK_SELECTOR}", text: name).click
         end
 
+        def click_link_in_section(section_name, link_name)
+          find_section(section_name.parameterize).find(
+            ".#{SIDEBAR_SECTION_LINK_SELECTOR}[data-link-name=\"#{link_name.parameterize}\"]",
+          ).click
+        end
+
         def has_one_active_section_link?
           has_css?(".#{SIDEBAR_SECTION_LINK_SELECTOR}--active", count: 1)
         end
@@ -30,6 +48,10 @@ module PageObjects
           has_css?(".sidebar-sections [data-section-name='#{name.parameterize}']")
         end
 
+        def has_no_section?(name)
+          has_no_css?(".sidebar-sections [data-section-name='#{name.parameterize}']")
+        end
+
         def switch_to_chat
           find(".sidebar__panel-switch-button[data-key='chat']").click
         end