Add a new setting to choose the server landing page (#36588)

spec/system/home_spec.rb

@@ -23,5 +23,41 @@ RSpec.describe 'Home page' do
         .to have_css('noscript', text: /Mastodon/)
         .and have_css('body', class: 'app-body')
     end
+
+    context 'when the landing page is set to about' do
+      before do
+        Setting.landing_page = 'about'
+      end
+
+      it 'visits the root path and is redirected to the about page', :js do
+        visit root_path
+
+        expect(page).to have_current_path('/about')
+      end
+    end
+
+    context 'when the landing page is set to trends' do
+      before do
+        Setting.landing_page = 'trends'
+      end
+
+      it 'visits the root path and is redirected to the trends page', :js do
+        visit root_path
+
+        expect(page).to have_current_path('/explore')
+      end
+    end
+
+    context 'when the landing page is set to local_feed' do
+      before do
+        Setting.landing_page = 'local_feed'
+      end
+
+      it 'visits the root path and is redirected to the local live feed page', :js do
+        visit root_path
+
+        expect(page).to have_current_path('/public/local')
+      end
+    end
   end
 end