Standing Orders: adding routing and controller action for deleting standing line items

app/controllers/admin/standing_line_items_controller.rb

@@ -7,6 +7,11 @@ module Admin
 
     respond_to :json
 
+    respond_override destroy: { json: {
+      success: lambda { render nothing: true, :status => 204 },
+      failure: lambda { render json: { errors: @standing_line_item.errors.full_messages }, status: :unprocessable_entity }
+    } }
+
     def build
       return render json: { errors: ['Unauthorised'] }, status: :unauthorized unless @shop
       if @variant

app/models/spree/ability_decorator.rb

@@ -257,6 +257,9 @@ class AbilityDecorator
       user.enterprises.include?(standing_order.shop)
     end
     can [:admin, :build], StandingLineItem
+    can [:destroy], StandingLineItem do |standing_line_item|
+      user.enterprises.include?(standing_line_item.standing_order.shop)
+    end
   end
 
   def add_relationship_management_abilities(user)

config/routes.rb

@@ -179,7 +179,7 @@ Openfoodnetwork::Application.routes.draw do
 
     resources :standing_orders, only: [:index, :new, :create, :edit, :update]
 
-    resources :standing_line_items, only: [], format: :json do
+    resources :standing_line_items, only: [:destroy], format: :json do
       post :build, on: :collection
     end
   end

spec/controllers/admin/standing_line_items_controller_spec.rb

@@ -95,4 +95,30 @@ describe Admin::StandingLineItemsController, type: :controller do
       end
     end
   end
+
+  describe "destroy" do
+    let!(:standing_order) { create(:standing_order_with_items) }
+    let!(:item) { standing_order.standing_line_items.first }
+    let!(:user) { create(:user) }
+    let(:params) { { format: :json, id: item.id } }
+
+    context 'as an enterprise user' do
+      before { allow(controller).to receive(:spree_current_user) { user } }
+
+      context "that does not manage the relevant shop" do
+        it "returns an error" do
+          spree_post :destroy, params
+          expect(response).to redirect_to spree.unauthorized_path
+        end
+      end
+
+      context 'that manages that relevant shop' do
+        before { standing_order.shop.update_attributes(owner: user) }
+
+        it 'removes the item' do
+          expect{ spree_post :destroy, params }.to change{standing_order.standing_line_items.count}.by(-1)
+        end
+      end
+    end
+  end
 end

spec/factories.rb

@@ -149,6 +149,15 @@ FactoryGirl.define do
     begins_at { 1.month.ago }
   end
 
+  factory :standing_order_with_items, parent: :standing_order do |standing_order|
+    standing_line_items { create_list(:standing_line_item, 3) }
+    before(:create) do |standing_order, proxy|
+      oc = standing_order.schedule.order_cycles.first
+      ex = create(:exchange, :order_cycle => oc, :sender => standing_order.shop, :receiver => standing_order.shop, :incoming => false, :pickup_time => 'time', :pickup_instructions => 'instructions')
+      standing_order.standing_line_items.each { |sli| ex.variants << sli.variant }
+    end
+  end
+
   factory :standing_line_item, :class => StandingLineItem do
     standing_order
     variant