DB and model changes to make ShippingMethod distributor habtm

app/models/spree/shipping_method_decorator.rb

@@ -1,23 +1,20 @@
 Spree::ShippingMethod.class_eval do
-  belongs_to :distributor, class_name: 'Enterprise'
-  attr_accessible :distributor_id
-
-  validates_presence_of :distributor_id
+  has_and_belongs_to_many :distributors, join_table: 'distributors_shipping_methods', :class_name => 'Enterprise', association_foreign_key: 'distributor_id'
+  attr_accessible :distributor_ids
 
   scope :by_distributor, lambda {
-    joins(:distributor).
+    joins(:distributors).
     order('enterprises.name, spree_shipping_methods.name').
     select('enterprises.*, spree_shipping_methods.*')
   }
 
   def available_to_order_with_distributor_check?(order, display_on=nil)
     available_to_order_without_distributor_check?(order, display_on) &&
-      (order.distributor == self.distributor)
+      self.distributors.include?(order.distributor)
   end
   alias_method_chain :available_to_order?, :distributor_check
 
   def adjustment_label
     'Delivery'
   end
-
 end

db/migrate/20131016230055_convert_shipping_methods_distributors_to_habtm.rb

@@ -0,0 +1,37 @@
+class ConvertShippingMethodsDistributorsToHabtm < ActiveRecord::Migration
+  class Spree::ShippingMethod < ActiveRecord::Base
+    belongs_to :distributor, class_name: 'Enterprise'
+    has_and_belongs_to_many :distributors, join_table: 'distributors_shipping_methods', :class_name => 'Enterprise', association_foreign_key: 'distributor_id'
+  end
+
+  def up
+    create_table :distributors_shipping_methods, id: false do |t|
+      t.references :distributor
+      t.references :shipping_method
+    end
+    add_index :distributors_shipping_methods, :distributor_id
+    add_index :distributors_shipping_methods, :shipping_method_id
+
+    Spree::ShippingMethod.all.each do |sm|
+      sm.distributors << sm.distributor if sm.distributor_id
+    end
+
+    remove_column :spree_shipping_methods, :distributor_id
+  end
+
+  def down
+    add_column :spree_shipping_methods, :distributor_id, :integer
+    add_index :spree_shipping_methods, :distributor_id
+
+    Spree::ShippingMethod.all.each do |sm|
+      if sm.distributors.present?
+        sm.distributor = sm.distributors.first
+        sm.save!
+
+        say "WARNING: Discarding #{sm.distributors.count-1} distributors while flattening HABTM relation to belongs_to" if sm.distributors.count > 1
+      end
+    end
+
+    drop_table :distributors_shipping_methods
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20130919010513) do
+ActiveRecord::Schema.define(:version => 20131016230055) do
 
   create_table "adjustment_metadata", :force => true do |t|
     t.integer "adjustment_id"
@@ -154,6 +154,14 @@ ActiveRecord::Schema.define(:version => 20130919010513) do
     t.integer "payment_method_id"
   end
 
+  create_table "distributors_shipping_methods", :id => false, :force => true do |t|
+    t.integer "distributor_id"
+    t.integer "shipping_method_id"
+  end
+
+  add_index "distributors_shipping_methods", ["distributor_id"], :name => "index_distributors_shipping_methods_on_distributor_id"
+  add_index "distributors_shipping_methods", ["shipping_method_id"], :name => "index_distributors_shipping_methods_on_shipping_method_id"
+
   create_table "enterprise_fees", :force => true do |t|
     t.integer  "enterprise_id"
     t.string   "fee_type"
@@ -462,9 +470,9 @@ ActiveRecord::Schema.define(:version => 20130919010513) do
     t.string   "email"
     t.text     "special_instructions"
     t.integer  "distributor_id"
+    t.integer  "order_cycle_id"
     t.string   "currency"
     t.string   "last_ip_address"
-    t.integer  "order_cycle_id"
     t.integer  "cart_id"
   end
 
@@ -721,11 +729,8 @@ ActiveRecord::Schema.define(:version => 20130919010513) do
     t.boolean  "match_all"
     t.boolean  "match_one"
     t.datetime "deleted_at"
-    t.integer  "distributor_id"
   end
 
-  add_index "spree_shipping_methods", ["distributor_id"], :name => "index_spree_shipping_methods_on_distributor_id"
-
   create_table "spree_skrill_transactions", :force => true do |t|
     t.string   "email"
     t.float    "amount"

spec/factories.rb

@@ -151,7 +151,7 @@ FactoryGirl.modify do
   end
 
   factory :shipping_method do
-    distributor { Enterprise.is_distributor.first || FactoryGirl.create(:distributor_enterprise) }
+    distributors { [Enterprise.is_distributor.first || FactoryGirl.create(:distributor_enterprise)] }
     display_on ''
   end
 
@@ -168,7 +168,7 @@ FactoryGirl.modify do
   end
 
   factory :payment_method do
-    distributors { [Enterprise.is_distributor.first || FactoryGirl.create(:distributor_enterprise)] } #Always need a distributor
+    distributors { [Enterprise.is_distributor.first || FactoryGirl.create(:distributor_enterprise)] }
   end
 
 end

spec/models/spree/shipping_method_spec.rb

@@ -6,15 +6,34 @@ module Spree
       build(:shipping_method).should be_valid
     end
 
-    it "requires a distributor" do
-      build(:shipping_method, distributor: nil).should_not be_valid
+    it "can have distributors" do
+      d1 = create(:distributor_enterprise)
+      d2 = create(:distributor_enterprise)
+      sm = create(:shipping_method)
+
+      sm.distributors.clear
+      sm.distributors << d1
+      sm.distributors << d2
+
+      sm.reload.distributors.should == [d1, d2]
+    end
+
+    it "can order by distributor" do
+      d1 = create(:distributor_enterprise, name: '222')
+      d2 = create(:distributor_enterprise, name: '111')
+
+      sm1 = create(:shipping_method, distributors: [d2], name: 'ZZ')
+      sm2 = create(:shipping_method, distributors: [d1], name: 'BB')
+      sm3 = create(:shipping_method, distributors: [d1], name: 'AA')
+
+      ShippingMethod.by_distributor.should == [sm1, sm3, sm2]
     end
 
     describe "availability" do
       let(:sm) { build(:shipping_method) }
 
       it "is available to orders that match its distributor" do
-        o = build(:order, ship_address: build(:address), distributor: sm.distributor)
+        o = build(:order, ship_address: build(:address), distributor: sm.distributors.first)
         sm.should be_available_to_order o
       end