Add Api::CouponCodesController#destroy endpoint

api/app/controllers/spree/api/coupon_codes_controller.rb

@@ -3,8 +3,8 @@
 module Spree
   module Api
     class CouponCodesController < Spree::Api::BaseController
-      before_action :load_order, only: :create
-      around_action :lock_order, only: :create
+      before_action :load_order
+      around_action :lock_order
 
       def create
         authorize! :update, @order, order_token
@@ -20,6 +20,20 @@ def create
         end
       end
 
+      def destroy
+        authorize! :update, @order, order_token
+
+        @order.coupon_code = params[:id]
+        @handler = PromotionHandler::Coupon.new(@order).remove
+
+        if @handler.successful?
+          render 'spree/api/promotions/handler', status: 200
+        else
+          logger.error("remove_coupon_code_error=#{@handler.error.inspect}")
+          render 'spree/api/promotions/handler', status: 422
+        end
+      end
+
       private
 
       def load_order

api/config/routes.rb

@@ -68,7 +68,7 @@
         put :apply_coupon_code
       end
 
-      resources :coupon_codes, only: :create
+      resources :coupon_codes, only: [:create, :destroy]
     end
 
     resources :zones

api/spec/requests/spree/api/coupon_codes_controller_spec.rb

@@ -56,5 +56,50 @@ module Spree
         end
       end
     end
+
+    describe '#destroy' do
+      let(:promo) {
+        create(:promotion_with_item_adjustment,
+               code: 'tenoff',
+               per_code_usage_limit: 5,
+               adjustment_rate: 10)
+      }
+
+      let(:promo_code) { promo.codes.first }
+      let(:order) { create(:order_with_line_items, user: current_api_user) }
+
+      before do
+        post spree.api_order_coupon_codes_path(order), params: { coupon_code: promo_code.value }
+        delete spree.api_order_coupon_code_path(order, promo_code.value)
+      end
+
+      context 'when successful' do
+        it 'removes the coupon' do
+          expect(response.status).to eq(200)
+          expect(order.reload.promotions).to eq([])
+          expect(json_response).to eq({
+            "success" => I18n.t('spree.coupon_code_removed'),
+            "error" => nil,
+            "successful" => true,
+            "status_code" => "coupon_code_removed"
+          })
+        end
+      end
+
+      context 'when unsuccessful' do
+        it 'returns an error' do
+          delete spree.api_order_coupon_code_path(order, promo_code.value)
+
+          expect(response.status).to eq(422)
+          expect(order.reload.promotions).to eq([])
+          expect(json_response).to eq({
+            "success" => nil,
+            "error" => I18n.t('spree.coupon_code_not_present'),
+            "successful" => false,
+            "status_code" => "coupon_code_not_present"
+          })
+        end
+      end
+    end
   end
 end

core/app/models/spree/promotion_handler/coupon.rb

@@ -25,6 +25,20 @@ def apply
         self
       end
 
+      def remove
+        if promotion.blank?
+          set_error_code :coupon_code_not_found
+        elsif !promotion_exists_on_order?(order, promotion)
+          set_error_code :coupon_code_not_present
+        else
+          promotion.remove_from(order)
+          order.recalculate
+          set_success_code :coupon_code_removed
+        end
+
+        self
+      end
+
       def set_success_code(status_code)
         @status_code = status_code
         @success = I18n.t(status_code, scope: 'spree')
@@ -56,6 +70,7 @@ def promotion_code
       def handle_present_promotion(promotion)
         return promotion_usage_limit_exceeded if promotion.usage_limit_exceeded? || promotion_code.usage_limit_exceeded?
         return promotion_applied if promotion_exists_on_order?(order, promotion)
+
         unless promotion.eligible?(order, promotion_code: promotion_code)
           self.error = promotion.eligibility_errors.full_messages.first unless promotion.eligibility_errors.blank?
           return (error || ineligible_for_this_order)

core/config/locales/en.yml

@@ -1177,6 +1177,9 @@ en:
     coupon_code_max_usage: Coupon code usage limit exceeded
     coupon_code_not_eligible: This coupon code is not eligible for this order
     coupon_code_not_found: The coupon code you entered doesn't exist. Please try again.
+    coupon_code_not_present: The coupon code you are trying to remove is not present
+      on this order.
+    coupon_code_removed: The coupon code was successfully removed from this order.
     coupon_code_unknown_error: This coupon code could not be applied to the cart at
       this time.
     create: Create