Handle duplicate [withdrawn] in page title

Author: sairamya93

app/helpers/application_helper.rb

@@ -6,7 +6,7 @@ def page_title(content_item = nil)
 
   def build_page_title(elements = [], withdrawn: false)
     title = (elements + ["GOV.UK"]).compact.join(" - ")
-    withdrawn ? "[Withdrawn] #{title}" : title
+    withdrawn && !title.start_with?("[Withdrawn]") ? "[Withdrawn] #{title}" : title
   end
 
   def current_path_without_query_string

spec/helpers/application_helper_spec.rb

@@ -41,6 +41,10 @@
     it "prepends the withdrawn tag if flag is set" do
       expect(build_page_title(["Title", nil, "Type"], withdrawn: true)).to eq("[Withdrawn] Title - Type - GOV.UK")
     end
+
+    it "does not prepend when title has withdrawn already" do
+      expect(build_page_title(["[Withdrawn] Title", nil, "Type"], withdrawn: true)).to eq("[Withdrawn] Title - Type - GOV.UK")
+    end
   end
 
   describe "#current_path_without_query_string" do