Fix method in dashboard link for disabling admin mode

The link for bigger screen sizes has incorrectly GET as method

app/views/layouts/nav/_dashboard.html.haml

@@ -76,7 +76,7 @@
   - if Feature.enabled?(:user_mode_in_session)
     - if header_link?(:admin_mode)
       = nav_link(controller: 'admin/sessions', html_options: { class: "d-none d-lg-block d-xl-block"}) do
-        = link_to destroy_admin_session_path, title: _('Leave Admin Mode'), aria: { label: _('Leave Admin Mode') }, data: { toggle: 'tooltip', placement: 'bottom', container: 'body' } do
+        = link_to destroy_admin_session_path, method: :post, title: _('Leave Admin Mode'), aria: { label: _('Leave Admin Mode') }, data: { toggle: 'tooltip', placement: 'bottom', container: 'body' } do
           = sprite_icon('lock-open', size: 18)
     - elsif current_user.admin?
       = nav_link(controller: 'admin/sessions', html_options: { class: "d-none d-lg-block d-xl-block"}) do

changelogs/unreleased/fix-disable-admin-mode-link-in-dashboard.yml

+---
+title: Fix POST method in dashboard link for disabling admin mode
+merge_request: 23363
+author: Diego Louzán
+type: fixed

spec/features/admin/admin_settings_spec.rb

@@ -9,7 +9,7 @@ describe 'Admin updates settings', :clean_gitlab_redis_shared_state, :do_not_moc
 
   let(:admin) { create(:admin) }
 
-  context 'feature flag :user_mode_in_session is enabled' do
+  context 'feature flag :user_mode_in_session is enabled', :request_store do
     before do
       stub_env('IN_MEMORY_APPLICATION_SETTINGS', 'false')
       sign_in(admin)
@@ -486,10 +486,24 @@ describe 'Admin updates settings', :clean_gitlab_redis_shared_state, :do_not_moc
         end
       end
 
-      it 'can leave admin mode' do
+      it 'can leave admin mode using main dashboard link', :js do
         page.within('.navbar-sub-nav') do
-          # Select first, link is also included in mobile view list
-          click_on 'Leave Admin Mode', match: :first
+          click_on 'Leave Admin Mode'
+
+          expect(page).to have_link(href: new_admin_session_path)
+        end
+      end
+
+      it 'can leave admin mode using dropdown menu on smaller screens', :js do
+        resize_screen_xs
+        visit root_dashboard_path
+
+        find('.header-more').click
+
+        page.within '.navbar-sub-nav' do
+          click_on 'Leave Admin Mode'
+
+          find('.header-more').click
 
           expect(page).to have_link(href: new_admin_session_path)
         end