Allow fast checkout without re-accepting old terms

We did that for the shop's terms already and now do it for the platform
terms as well.

app/helpers/terms_and_conditions_helper.rb

@@ -23,6 +23,19 @@ module TermsAndConditionsHelper
     current_order.distributor.terms_and_conditions.file?
   end
 
+  def all_terms_and_conditions_already_accepted?
+    platform_tos_already_accepted? && terms_and_conditions_already_accepted?
+  end
+
+  def platform_tos_already_accepted?
+    customer_terms_and_conditions_accepted_at = spree_current_user&.
+      customer_of(current_order.distributor)&.terms_and_conditions_accepted_at
+
+    customer_terms_and_conditions_accepted_at.present? &&
+      (customer_terms_and_conditions_accepted_at >
+       TermsOfServiceFile.updated_at)
+  end
+
   def terms_and_conditions_already_accepted?
     customer_terms_and_conditions_accepted_at = spree_current_user&.
       customer_of(current_order.distributor)&.terms_and_conditions_accepted_at

app/models/terms_of_service_file.rb

@@ -13,4 +13,10 @@ class TermsOfServiceFile < ApplicationRecord
   def self.current_url
     current&.attachment&.url || Spree::Config.footer_tos_url
   end
+
+  # If no file has been uploaded, we don't know when the old terms have
+  # been updated last. So we return the most recent possible update time.
+  def self.updated_at
+    current&.updated_at || Time.zone.now
+  end
 end

app/views/checkout/_all_terms_and_conditions.html.haml

@@ -1,4 +1,4 @@
 %p
-  %input{ type: 'checkbox', id: 'accept_terms', ng: { model: "terms_and_conditions_accepted", init: "terms_and_conditions_accepted=false" } }
+  %input{ type: 'checkbox', id: 'accept_terms', ng: { model: "terms_and_conditions_accepted", init: "terms_and_conditions_accepted = #{all_terms_and_conditions_already_accepted?}" } }
   %label.small{for: "accept_terms"}
     = t('.message_html', terms_and_conditions_link: link_to( t(".terms_and_conditions"), current_order.distributor.terms_and_conditions.url, target: '_blank'), tos_link: link_to_platform_terms)

app/views/checkout/_platform_terms_of_service.html.haml

@@ -1,4 +1,4 @@
 %p
-  %input{ type: "checkbox", id: "platform_tos_accepted", ng: { model: "platform_tos_accepted", init: "platform_tos_accepted = false" } }
+  %input{ type: "checkbox", id: "platform_tos_accepted", ng: { model: "platform_tos_accepted", init: "platform_tos_accepted = #{platform_tos_already_accepted?}" } }
   %label.small{for: "platform_tos_accepted"}
     = t(".message_html", tos_link: link_to_platform_terms)

spec/features/consumer/shopping/checkout_spec.rb

@@ -200,6 +200,32 @@ feature "As a consumer I want to check out my cart", js: true do
         uncheck "Terms of service"
         expect(page).to have_button("Place order now", disabled: true)
       end
+
+      context "when the terms have been accepted in the past" do
+        before do
+          TermsOfServiceFile.create!(
+            attachment: File.open(Rails.root.join("public/Terms-of-service.pdf")),
+            updated_at: 1.day.ago,
+          )
+          customer = create(:customer, enterprise: order.distributor, user: user)
+          customer.update(terms_and_conditions_accepted_at: Time.zone.now)
+        end
+
+        it "remembers the acceptance" do
+          visit checkout_path
+
+          within "#checkout_form" do
+            expect(page).to have_link("Terms of service")
+            expect(page).to have_button("Place order now", disabled: false)
+          end
+
+          uncheck "Terms of service"
+          expect(page).to have_button("Place order now", disabled: true)
+
+          check "Terms of service"
+          expect(page).to have_button("Place order now", disabled: false)
+        end
+      end
     end
 
     context "when the seller's terms and the platform's terms have to be accepted" do

spec/models/terms_of_service_file_spec.rb

@@ -33,4 +33,22 @@ describe TermsOfServiceFile do
       expect(subject).to match /^\/system\/terms_of_service_files\/attachments.*Terms-of-service\.pdf\?\d+$/
     end
   end
+
+  describe ".updated_at" do
+    let(:subject) { TermsOfServiceFile.updated_at }
+
+    it "gives the most conservative time if not known" do
+      Timecop.freeze do
+        expect(subject).to eq Time.zone.now
+      end
+    end
+
+    it "returns the time when the terms were last updated" do
+      update_time = 1.day.ago
+      file = TermsOfServiceFile.create!(attachment: pdf, updated_at: update_time)
+
+      # The database isn't as precise as Ruby's time and rounds.
+      expect(subject).to be_within(0.001).of(update_time)
+    end
+  end
 end