Add test, change error message wording

app/models/scheme.rb

@@ -212,7 +212,7 @@ class Scheme < ApplicationRecord
     required_attributes = attribute_names - %w[id created_at updated_at old_id old_visible_id confirmed end_date sensitive secondary_client_group total_units has_other_client_group]
 
     if confirmed == true && required_attributes.any? { |attribute| self[attribute].blank? }
-      errors.add :base, "Please answer all the required questions"
+      errors.add :base
     end
   end
 end

config/locales/en.yml

@@ -65,6 +65,8 @@ en:
               invalid: "Select if this scheme provides for another client group"
             arrangement_type:
               invalid: "Select who provides the support services used by this scheme"
+            base:
+              invalid: "You must answer all the required questions for this scheme"
         location:
           attributes:
             startdate:

spec/requests/schemes_controller_spec.rb

@@ -557,13 +557,22 @@ RSpec.describe SchemesController, type: :request do
 
     context "when signed in as a data coordinator" do
       let(:user) { FactoryBot.create(:user, :data_coordinator) }
-      let(:scheme_to_update) { FactoryBot.create(:scheme, owning_organisation: user.organisation) }
+      let(:scheme_to_update) { FactoryBot.create(:scheme, owning_organisation: user.organisation, confirmed: nil) }
 
       before do
         sign_in user
         patch "/schemes/#{scheme_to_update.id}", params:
       end
 
+      context "when confirming the scheme" do
+        let(:params) { { scheme: { owning_organisation_id: user.organisation.id, arrangement_type: "V", confirmed: true, page: "check-answers" } } }
+
+        it "does not allow the scheme to be confirmed" do
+          expect(response).to have_http_status(:unprocessable_entity)
+          expect(page).to have_content(I18n.t("activerecord.errors.models.scheme.attributes.base.invalid"))
+        end
+      end
+
       context "when params are missing" do
         let(:params) do
           { scheme: {