Use class_name as attributes instead of class itself

.rspec_status

 example_id                                 | status | run_time        |
 ------------------------------------------ | ------ | --------------- |
-./spec/shotengai/models_spec.rb[1:1:1:1]   | passed | 0.36278 seconds |
-./spec/shotengai/models_spec.rb[1:1:1:2]   | passed | 0.24106 seconds |
-./spec/shotengai/models_spec.rb[1:1:2:1]   | passed | 0.19389 seconds |
-./spec/shotengai/models_spec.rb[1:1:2:2]   | passed | 0.19885 seconds |
-./spec/shotengai/models_spec.rb[1:1:2:3]   | passed | 0.22058 seconds |
-./spec/shotengai/models_spec.rb[1:1:3:1]   | passed | 0.202 seconds   |
-./spec/shotengai/models_spec.rb[1:1:3:2]   | passed | 0.20022 seconds |
-./spec/shotengai/models_spec.rb[1:1:3:3]   | passed | 0.20972 seconds |
-./spec/shotengai/models_spec.rb[1:1:4:1]   | passed | 0.23258 seconds |
-./spec/shotengai/models_spec.rb[1:1:5:1]   | passed | 0.23735 seconds |
-./spec/shotengai/models_spec.rb[1:1:5:2:1] | passed | 0.23552 seconds |
-./spec/shotengai/models_spec.rb[1:1:5:2:2] | passed | 0.25856 seconds |
+./spec/shotengai/models_spec.rb[1:1:1:1]   | passed | 0.36006 seconds |
+./spec/shotengai/models_spec.rb[1:1:1:2]   | passed | 0.19221 seconds |
+./spec/shotengai/models_spec.rb[1:1:2:1]   | passed | 0.19696 seconds |
+./spec/shotengai/models_spec.rb[1:1:2:2]   | passed | 0.17745 seconds |
+./spec/shotengai/models_spec.rb[1:1:2:3]   | passed | 0.17437 seconds |
+./spec/shotengai/models_spec.rb[1:1:3:1]   | passed | 0.19322 seconds |
+./spec/shotengai/models_spec.rb[1:1:3:2]   | passed | 0.1998 seconds  |
+./spec/shotengai/models_spec.rb[1:1:3:3]   | passed | 0.2012 seconds  |
+./spec/shotengai/models_spec.rb[1:1:4:1]   | passed | 0.22549 seconds |
+./spec/shotengai/models_spec.rb[1:1:5:1]   | passed | 0.19514 seconds |
+./spec/shotengai/models_spec.rb[1:1:5:2:1] | passed | 0.25054 seconds |
+./spec/shotengai/models_spec.rb[1:1:5:2:2] | passed | 0.22609 seconds |
 ./spec/shotengai/models_spec.rb[1:2:1:1]   | passed | 0.22996 seconds |
 ./spec/shotengai/models_spec.rb[1:2:1:2]   | passed | 0.2075 seconds  |
 ./spec/shotengai/models_spec.rb[1:2:2:1]   | passed | 0.46901 seconds |

lib/shotengai.rb

 require "shotengai/version"
 require 'rails'
 require 'active_record'
-Dir['./lib/shotengai/*'].each { |f| require f }
+Dir['./lib/shotengai/*.rb'].each { |f| require f }
 
 module Shotengai
   # Your code goes here...

lib/shotengai/buyer.rb

@@ -6,7 +6,8 @@ module Shotengai
     end
 
     class_methods do
-      def can_shopping_with klass, options={}
+      def can_shopping_with klass_name, options={}
+        klass = Object.const_get(klass_name)
         unless Shotengai::Order <=> klass # 为子类
           raise ArgumentError.new('You can only buy the class inherit from Shotengai::Order') 
         end

lib/shotengai/cart.rb

@@ -24,7 +24,8 @@ module Shotengai
     default_scope { where(status: 'cart') } 
 
     class << self
-      def can_buy *good_classes
+      def can_buy *good_class_names
+        good_classes = good_class_names.map { |name| Object.const_get(name) }
         # 所有snapshot
         has_many :snapshots, -> { 
             where(type: good_classes.map { |good_class| "#{good_class.name}Snapshot" }) 

lib/shotengai/order.rb

@@ -41,7 +41,6 @@ module Shotengai
     end
 
     def fill_snapshot
-      p 'cmm   222'
       ActiveRecord::Base.transaction {
         self.snapshots.each(&:copy_info)
       }
@@ -80,7 +79,8 @@ module Shotengai
         super
       end
 
-      def can_buy *good_classes
+      def can_buy *good_class_names
+        good_classes = good_class_names.map { |name| Object.const_get(name) }
         # 所有snapshot
         has_many :snapshots, -> { 
             where(type: good_classes.map { |good_class| "#{good_class.name}Snapshot" }) 
@@ -102,7 +102,7 @@ module Shotengai
           ) 
         end
 
-        self.cart_class.can_buy *good_classes
+        self.cart_class.can_buy *good_class_names
       end
     end
   end

spec/shotengai/models_spec.rb

@@ -29,12 +29,12 @@ RSpec.describe 'Shotengai Models' do
       class OtherGood < Shotengai::Product; end
 
       class TestOrder < Shotengai::Order
-        can_buy ::TestGood
+        can_buy 'TestGood'
       end
 
       class TestBuyer < ActiveRecord::Base
         include Shotengai::Buyer
-        can_shopping_with ::TestOrder
+        can_shopping_with 'TestOrder'
         
         ActiveRecord::Base.connection.create_table(:test_buyers) unless ActiveRecord::Base.connection.table_exists?(:test_buyers)
       end