Route back to the check answers if answer is changed from check answers page

app/controllers/form_controller.rb

@@ -8,7 +8,9 @@ class FormController < ApplicationController
       @page = @case_log.form.get_page(params[:case_log][:page])
       responses_for_page = responses_for_page(@page)
       if @case_log.update(responses_for_page)
-        if @case_log.form.is_last_question?(@page, @case_log.form.subsection_for_page(@page), @case_log)
+        if is_referrer_check_answers?
+          redirect_to(send("case_log_#{@case_log.form.subsection_for_page(@page).id}_check_answers_path", @case_log))
+        elsif @case_log.form.is_last_question?(@page, @case_log.form.subsection_for_page(@page), @case_log)
           redirect_to(case_logs_path)
         else
           redirect_path = @case_log.form.next_page_redirect_path(@page, @case_log)
@@ -88,4 +90,9 @@ private
   def find_resource_by_named_id
     @case_log = current_user.case_logs.find_by(id: params[:case_log_id])
   end
+
+  def is_referrer_check_answers?
+    referrer = request.headers["HTTP_REFERER"].presence || ""
+    referrer.present? && CGI.parse(referrer.split("?")[-1]).present? && CGI.parse(referrer.split("?")[-1])["referrer"][0] == "check_answers"
+  end
 end

app/views/form/_check_answers_table.html.erb

@@ -9,6 +9,6 @@
     <% end %>
   </dd>
   <dd class="govuk-summary-list__actions">
-    <%= govuk_link_to(question.update_answer_link_name(@case_log), "/logs/#{@case_log.id}/#{question.page.id.to_s.dasherize}").html_safe %>
+    <%= govuk_link_to(question.update_answer_link_name(@case_log), "/logs/#{@case_log.id}/#{question.page.id.to_s.dasherize}?referrer=check_answers").html_safe %>
   </dd>
 </div>

db/schema.rb

@@ -319,6 +319,7 @@ ActiveRecord::Schema[7.0].define(version: 202202071123100) do
     t.boolean "is_dpo", default: false
     t.boolean "is_key_contact", default: false
     t.string "phone"
+    t.boolean "is_dpo", default: false
     t.index ["email"], name: "index_users_on_email", unique: true
     t.index ["organisation_id"], name: "index_users_on_organisation_id"
     t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true

spec/features/form/check_answers_page_spec.rb

@@ -71,10 +71,10 @@ RSpec.describe "Form Check Answers Page" do
     # Regex explanation: match the string "Answer" but not if it's follow by "the missing questions"
     # This way only the links in the table will get picked up
     it "has an answer link for questions missing an answer" do
-      visit("/logs/#{empty_case_log.id}/#{subsection}/check-answers")
+      visit("/logs/#{empty_case_log.id}/#{subsection}/check-answers?referrer=check_answers")
       assert_selector "a", text: /Answer (?!the missing questions)/, count: 5
       assert_selector "a", text: "Change", count: 0
-      expect(page).to have_link("Answer", href: "/logs/#{empty_case_log.id}/person-1-age")
+      expect(page).to have_link("Answer", href: "/logs/#{empty_case_log.id}/person-1-age?referrer=check_answers")
     end
 
     it "has a change link for answered questions" do
@@ -82,7 +82,7 @@ RSpec.describe "Form Check Answers Page" do
       visit("/logs/#{empty_case_log.id}/#{subsection}/check-answers")
       assert_selector "a", text: /Answer (?!the missing questions)/, count: 4
       assert_selector "a", text: "Change", count: 1
-      expect(page).to have_link("Change", href: "/logs/#{empty_case_log.id}/person-1-age")
+      expect(page).to have_link("Change", href: "/logs/#{empty_case_log.id}/person-1-age?referrer=check_answers")
     end
 
     it "updates the change/answer link when answers get updated" do
@@ -95,7 +95,7 @@ RSpec.describe "Form Check Answers Page" do
       visit("/logs/#{empty_case_log.id}/household-needs/check-answers")
       assert_selector "a", text: /Answer (?!the missing questions)/, count: 3
       assert_selector "a", text: "Change", count: 2
-      expect(page).to have_link("Change", href: "/logs/#{empty_case_log.id}/accessibility-requirements")
+      expect(page).to have_link("Change", href: "/logs/#{empty_case_log.id}/accessibility-requirements?referrer=check_answers")
     end
 
     it "does not display conditional questions that were not visited" do
@@ -127,6 +127,18 @@ RSpec.describe "Form Check Answers Page" do
       end
     end
 
+    context "when the user changes their answer" do
+      it "routes back to check answers" do
+        visit("/logs/#{empty_case_log.id}/accessibility-requirements")
+        check("case-log-accessibility-requirements-housingneeds-c-field")
+        click_button("Save and continue")
+        visit("/logs/#{empty_case_log.id}/household-needs/check-answers")
+        first("a", text: /Change/).click
+        click_button("Save and continue")
+        expect(page).to have_current_path("/logs/#{empty_case_log.id}/household-needs/check-answers")
+      end
+    end
+
     context "when the user wants to bypass the tasklist page from check answers" do
       let(:section_completed_case_log) do
         FactoryBot.create(