Allow editing and resetting of all admin setting strings

spec/features/admin/settings_spec.rb

@@ -30,9 +30,7 @@ RSpec.describe 'Admin/global settings', type: :feature do
       visit admin_settings_services_path(params: { s: "ejabberd" })
 
       expect(page).to have_content("Enable ejabberd integration")
-      expect(page).to have_field("API URL",
-        with: "http://xmpp.example.com/api",
-        disabled: true)
+      expect(page).to have_field("API URL", with: "http://xmpp.example.com/api")
     end
 
     scenario "Disable ejabberd integration" do
@@ -67,5 +65,16 @@ RSpec.describe 'Admin/global settings', type: :feature do
       expect(page).to_not have_checked_field("setting[remotestorage_enabled]")
       expect(page).to_not have_field("Storage URL", disabled: true)
     end
+
+    scenario "Resettable fields" do
+      visit admin_settings_services_path(params: { s: "ejabberd" })
+      expect(page).to have_field("API URL", with: "http://xmpp.example.com/api")
+      expect(page).to_not have_css('input#setting_ejabberd_api_url+button')
+
+      Setting.ejabberd_api_url = "http://example.com/foo"
+      visit admin_settings_services_path(params: { s: "ejabberd" })
+      expect(page).to have_field("API URL", with: "http://example.com/foo")
+      expect(page).to have_css('input#setting_ejabberd_api_url+button')
+    end
   end
 end