can not add more than max evidence in journeys

app/forms/referrals/allegation_evidence/uploaded_form.rb

@@ -3,11 +3,19 @@ module AllegationEvidence
     class UploadedForm < FormItem
       attr_accessor :more_evidence
 
-      validates :more_evidence, inclusion: { in: %w[yes no] }, on: :update
+      validates :more_evidence,
+        inclusion: { in: %w[yes no] },
+        on: :update,
+        if: Proc.new { |form| form.can_upload_more_evidence? }
+
 
       def more_evidence?
         @more_evidence == "yes"
       end
+
+      def can_upload_more_evidence?
+        referral.can_upload_more_evidence?
+      end
     end
   end
 end

app/views/public_referrals/allegation_evidence/check_answers/edit.html.erb

@@ -11,11 +11,13 @@
         Check and confirm your answers
       </h1>
 
-      <%= govuk_button_link_to(
-        "Add more evidence",
-        edit_public_referral_allegation_evidence_upload_path(current_referral),
-        class: "govuk-button--secondary govuk-!-margin-bottom-8"
-      ) if current_referral.has_evidence %>
+      <% if current_referral.can_upload_more_evidence? %>
+        <%= govuk_button_link_to(
+          "Add more evidence",
+          edit_public_referral_allegation_evidence_upload_path(current_referral),
+          class: "govuk-button--secondary govuk-!-margin-bottom-8"
+        ) if current_referral.has_evidence %>
+      <% end %>
 
       <%= render partial: 'referrals/shared/check_answers', locals: { f:, complete_field_name: :evidence_details_complete } %>
     <% end %>

app/views/public_referrals/allegation_evidence/uploaded/edit.html.erb

@@ -30,9 +30,11 @@
         <% end %>
       </dl>
 
-      <%= f.govuk_radio_buttons_fieldset(:more_evidence, legend: { size: "m", text: "Do you want to upload another file?" }) do %>
-        <%= f.govuk_radio_button :more_evidence, "yes", label: { text: "Yes" }, link_errors: true %>
-        <%= f.govuk_radio_button :more_evidence, "no", label: { text: "No" } %>
+      <% if f.object.referral.can_upload_more_evidence? %>
+        <%= f.govuk_radio_buttons_fieldset(:more_evidence, legend: { size: "m", text: "Do you want to upload another file?" }) do %>
+          <%= f.govuk_radio_button :more_evidence, "yes", label: { text: "Yes" }, link_errors: true %>
+          <%= f.govuk_radio_button :more_evidence, "no", label: { text: "No" } %>
+        <% end %>
       <% end %>
 
       <%= f.govuk_submit "Save and continue" %>

spec/system/public_referrals/user_adds_allegation_evidence_spec.rb

@@ -5,6 +5,34 @@
   include CommonSteps
   include SummaryListHelpers
 
+  scenario "A member of public uploads maximum number of evidence uploads" do
+    given_the_service_is_open
+    and_i_am_signed_in
+    and_the_referral_form_feature_is_active
+    and_i_am_a_member_of_the_public_with_an_existing_referral
+    and_i_visit_the_public_referral
+    then_i_see_the_public_referral_summary
+
+    when_i_edit_the_evidence
+    then_i_am_asked_if_i_have_evidence_to_upload
+
+    when_i_choose_yes_to_uploading_evidence
+    and_i_click_save_and_continue
+    then_i_am_asked_to_upload_evidence_files
+
+    when_i_upload_the_maximum_number_of_files
+    and_i_click_save_and_continue
+    then_i_see_a_list_of_max_uploaded_files
+    then_i_cannot_upload_another_file
+
+    when_i_click_save_and_continue
+    then_i_see_the_check_your_answers_page(
+      "Evidence and supporting information",
+      "allegation_evidence"
+    )
+    then_cannot_add_more_evidence
+  end
+
   scenario "A member of public adds evidence to referral" do
     given_the_service_is_open
     and_i_am_signed_in
@@ -311,4 +339,28 @@ def then_the_list_of_the_uploaded_files_should_be_empty
   def when_i_click_on_change_evidence
     click_on "Change if you have anything to upload"
   end
+
+  def when_i_upload_the_maximum_number_of_files
+    attach_file(
+      "Upload files",
+      FileUploadValidator::MAX_FILES.times.map {
+        Rails.root.join("spec/fixtures/files/upload1.pdf")
+      }
+    )
+  end
+
+  def then_i_cannot_upload_another_file
+    expect(page).not_to have_content("Do you want to upload another file?")
+  end
+
+  def then_cannot_add_more_evidence
+    expect(page).not_to have_content("Add more evidence")
+  end
+
+  def then_i_see_a_list_of_max_uploaded_files
+    expect(page).to have_content("Uploaded evidence")
+    within(".govuk-summary-list") do
+      expect(page).to have_link("upload1.pdf", count: 20, href: /active_storage/)
+    end
+  end
 end