Add factory for orders

lib/rex/order.rb

@@ -1,16 +1,14 @@
 module Rex
   class Order
     attr_accessor(
-      :next_order,
-      :remaining_amount
-    )
-
-    attr_reader(
       :id,
       :is_buy,
       :price,
       :user_id,
-      :amount
+      :amount,
+      :previous_order,
+      :next_order,
+      :remaining_amount
     )
 
     def initialize(attrs = {})
@@ -23,6 +21,7 @@ module Rex
       @remaining_amount = attrs[:amount]
 
       @next_order = nil
+      @previous_order = nil
     end
 
     def filled?

spec/factories/orders.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :order, class: Rex::Order do
+    sequence(:id) { |i| i }
+    sequence(:user_id) { |i| i }
+    sequence(:is_buy) { |i| (i % 2).zero? }
+    sequence(:price) { 100 }
+    sequence(:amount) { 20 }
+  end
+end

spec/order_spec.rb

@@ -3,9 +3,7 @@
 RSpec.describe Rex::Order do
   describe "#filled?" do
     let(:order) do
-      instance = described_class.new(
-        amount: 100
-      )
+      instance = build(:order)
       instance.remaining_amount = remaining_amount
       instance
     end