Add order price test

app/models/order_item.rb

@@ -13,7 +13,7 @@ class OrderItem < ActiveRecord::Base
   belongs_to :product
 
   validates :product, presence: true
-  validates :count, presence: true, numericality: { only_integer: true, greater_than_or_equal_to: 0 }
+  validates :count, presence: true, numericality: { only_integer: true, greater_than: 0 }
 
   after_create :remove_from_stock
 

spec/factories/order_items.rb

@@ -11,6 +11,7 @@
 FactoryGirl.define do
   factory :order_item do
     order
-    product
+    association :product, factory: :product
+    count { 1 + rand(5) }
   end
 end

spec/factories/orders.rb

@@ -15,8 +15,11 @@ require 'faker'
 FactoryGirl.define do
   factory :order do
     user
-    before(:create) do |order|
-      order.order_items << build(:order_item, order: order)
+    transient do
+      products_count 1
+    end
+    before(:create) do |order, evaluator|
+      order.order_items << create_list(:order_item, evaluator.products_count, order: order)
     end
   end
 end

spec/factories/products.rb

@@ -24,7 +24,7 @@ FactoryGirl.define do
   factory :product do
     name { Faker::Name.name }
     price_cents { rand 120 }
-    stock { rand 30 }
+    stock { 30 + rand(30) }
     calories { rand 20 }
     avatar { Identicon.data_url_for name }
   end

spec/models/order_item_spec.rb

@@ -24,6 +24,11 @@ describe OrderItem do
         @order_item.count = -5
         expect(@order_item).to_not be_valid
       end
+
+      it 'should not be 0' do
+        @order_item.count = 0
+        expect(@order_item).to_not be_valid
+      end
     end
   end
 

spec/models/order_spec.rb

@@ -37,9 +37,19 @@ describe Order do
     end
 
     it 'should change the orders_count' do
-      expect(@user.reload.orders_count).to eq(1)
-      @order.cancel
-      expect(@user.reload.orders_count).to eq(0)
+      expect{@order.cancel}.to change{@user.reload.orders_count}.by(-1)
+    end
+  end
+
+  describe 'price' do
+    it 'should be calculated from order_items' do
+      @order = build :order, products_count: 0
+      sum = (create_list :product, 1 + rand(10)).map do |p|
+        create(:order_item, order: @order, product: p, count: 1 + rand(5)) do |oi|
+          @order.order_items << oi
+        end
+      end.map{ |oi| oi.count * oi.product.price_cents }.sum
+      expect(@order.price_cents).to eq(sum)
     end
   end
 end