First take at adding a voucher to an order

Use voucher.create_adjustment to add an adjustment to the order
Currently doesn't take into account tax part

app/controllers/split_checkout_controller.rb

@@ -22,6 +22,9 @@ class SplitCheckoutController < ::BaseController
   before_action :hide_ofn_navigation, only: [:edit, :update]
 
   def edit
+    #  TODO Calculate percent amount covered by the voucher for display purposes
+    @voucher_adjustment = @order.vouchers.first
+
     redirect_to_step_based_on_order unless params[:step]
     check_step if params[:step]
     recalculate_tax if params[:step] == "summary"
@@ -30,6 +33,8 @@ class SplitCheckoutController < ::BaseController
   end
 
   def update
+    return add_voucher if payment_step? and params[:order][:voucher_code]
+
     if confirm_order || update_order
       return if performed?
 
@@ -179,10 +184,30 @@ class SplitCheckoutController < ::BaseController
     selected_shipping_method.first.require_ship_address == false
   end
 
+  def add_voucher
+    # Fetch Voucher
+    voucher = Voucher.find_by(code: params[:order][:voucher_code], enterprise: @order.distributor)
+
+    if voucher.nil?
+      @order.errors.add(:voucher, I18n.t('split_checkout.errors.voucher_not_found'))
+      return render_error
+    end
+
+    # Create adjustment
+    # TODO add tax part of adjustement
+    voucher.create_adjustment(voucher.code, @order)
+
+    redirect_to checkout_step_path(:payment)
+  end
+
   def summary_step?
     params[:step] == "summary"
   end
 
+  def payment_step?
+    params[:step] == "payment"
+  end
+
   def advance_order_state
     return if @order.complete?
 

app/views/split_checkout/_payment.html.haml

@@ -6,9 +6,12 @@
 
       .checkout-input.voucher
         .two-columns-inputs.voucher
-          = f.text_field :voucher_code, { placeholder: t("split_checkout.step2.voucher.placeholder"), class: "voucher" }
-          - # TODO: enable button when code entered
-          = f.submit t("split_checkout.step2.voucher.apply"), class: "button cancel voucher", disabled: true 
+          -if @voucher_adjustment.present?
+            = "Voucher used: #{@voucher_adjustment.label}"
+          - else
+            = f.text_field :voucher_code, { placeholder: t("split_checkout.step2.voucher.placeholder"), class: "voucher" }
+            - # TODO: enable button when code entered
+            = f.submit t("split_checkout.step2.voucher.apply"), class: "button cancel voucher", disabled: false 
         
     %div.checkout-title
       = t("split_checkout.step2.payment_method.title")

config/locales/en.yml

@@ -2091,6 +2091,7 @@ en:
       select_a_shipping_method: Select a shipping method
       select_a_payment_method: Select a payment method
       no_shipping_methods_available: Checkout is not possible due to absence of shipping options. Please contact the shop owner.
+      voucher_not_found: Not found
   order_paid: PAID
   order_not_paid: NOT PAID
   order_total: Total order

spec/system/consumer/split_checkout_spec.rb

@@ -729,6 +729,24 @@ describe "As a consumer, I want to checkout my order" do
           it "shows voucher input" do
             expect(page).to have_content "Apply voucher"
           end
+
+          describe "adding voucher to the order" do
+            context "voucher doesn't exist" do
+              it "show an error" do
+                fill_in "Enter voucher code", with: "non_code"
+                click_button("Apply")
+
+                expect(page).to have_content("Voucher Not found")
+              end
+            end
+
+            it "adds a voucher to the order" do
+              fill_in "Enter voucher code", with: voucher.code
+              click_button("Apply")
+
+              expect(page).to have_content("Voucher used: some_code")
+            end
+          end
         end
       end