Warn user deleting a group label affect all projects within the group

app/helpers/labels_helper.rb

@@ -155,6 +155,13 @@ module LabelsHelper
     label.subscribed?(current_user) ? 'Unsubscribe' : 'Subscribe'
   end
 
+  def label_deletion_confirm_text(label)
+    case label
+    when GroupLabel then 'Remove this label? This will affect all projects within the group. Are you sure?'
+    when ProjectLabel then 'Remove this label? Are you sure?'
+    end
+  end
+
   # Required for Banzai::Filter::LabelReferenceFilter
   module_function :render_colored_label, :render_colored_cross_project_label,
                   :text_color_for_bg, :escape_once

app/views/shared/_label.html.haml

@@ -44,7 +44,7 @@
       = link_to edit_label_path(label), title: "Edit", class: 'btn btn-transparent btn-action', data: {toggle: "tooltip"} do
         %span.sr-only Edit
         = icon('pencil-square-o')
-      = link_to destroy_label_path(label), title: "Delete", class: 'btn btn-transparent btn-action remove-row', method: :delete, remote: true, data: {confirm: "Remove this label? Are you sure?", toggle: "tooltip"} do
+      = link_to destroy_label_path(label), title: "Delete", class: 'btn btn-transparent btn-action remove-row', method: :delete, remote: true, data: {confirm: label_deletion_confirm_text(label), toggle: "tooltip"} do
         %span.sr-only Delete
         = icon('trash-o')