TaxRate M-M TaxCategory

CHANGELOG.md

@@ -3,6 +3,10 @@
 - Ignore `adjustment.finalized` on tax adjustments. [\#1936](https://github.com/solidusio/solidus/pull/1936) ([jordan-brough](https://github.com/jordan-brough))
 - Deprecate `#simple_current_order`
 [\#1915](https://github.com/solidusio/solidus/pull/1915) ([ericsaupe](https://github.com/ericsaupe))
+- Transform the relation between TaxRate and TaxCategory to a Many to Many [\#1851](https://github.com/solidusio/solidus/pull/1851) ([vladstoick](https://github.com/vladstoick))
+
+  This fixes issue [\#1836](https://github.com/solidusio/solidus/issues/1836). By allowing a TaxRate to tax multiple categories, stores don't have to create multiple TaxRates with the same value if a zone doesn't have different tax rates for some tax categories.
+
 
 ## Solidus 2.2.1 (2017-05-09)
 

backend/app/views/spree/admin/tax_rates/_form.html.erb

@@ -25,8 +25,8 @@
             <%= f.collection_select(:zone_id, @available_zones, :id, :name, {}, {class: 'select2 fullwidth'}) %>
           </div>
           <div data-hook="category" class="field">
-            <%= f.label :tax_category_id, Spree::TaxCategory.model_name.human %>
-            <%= f.collection_select(:tax_category_id, @available_categories,:id, :name, {}, {class: 'select2 fullwidth'}) %>
+            <%= f.label :tax_category_ids, Spree::TaxCategory.model_name.human %>
+            <%= f.collection_select(:tax_category_ids, @available_categories, :id, :name, {}, {class: 'select2 fullwidth', multiple: "multiple"}) %>
           </div>
           <div data-hook="show_rate" class="field">
             <%= f.check_box :show_rate_in_label %>

backend/app/views/spree/admin/tax_rates/index.html.erb

@@ -29,7 +29,7 @@
       <tr data-hook="rate_header">
         <th><%= Spree::TaxRate.human_attribute_name(:zone) %></th>
         <th><%= Spree::TaxRate.human_attribute_name(:name) %></th>
-        <th><%= Spree::TaxRate.human_attribute_name(:tax_category_id) %></th>
+        <th><%= Spree::TaxRate.human_attribute_name(:tax_categories) %></th>
         <th><%= Spree::TaxRate.human_attribute_name(:amount) %></th>
         <th><%= Spree::TaxRate.human_attribute_name(:included_in_price) %></th>
         <th><%= Spree::TaxRate.human_attribute_name(:show_rate_in_label) %></th>
@@ -42,7 +42,13 @@
       <tr id="<%= spree_dom_id tax_rate %>" data-hook="rate_row" class="<%= cycle('odd', 'even')%>">
         <td class="align-center"><%=tax_rate.zone.try(:name) || Spree.t(:not_available) %></td>
         <td class="align-center"><%=tax_rate.name %></td>
-        <td class="align-center"><%=tax_rate.tax_category.try(:name) || Spree.t(:not_available) %></td>
+        <td class="align-center">
+          <% if tax_rate.tax_categories.any? %>
+            <%= tax_rate.tax_categories.map(&:name).join(", ") %>
+          <% else %>
+            <%= Spree.t(:not_available) %>
+          <% end %>
+        </td>
         <td class="align-center"><%=tax_rate.amount %></td>
         <td class="align-center"><%=tax_rate.included_in_price? ? Spree.t(:say_yes) : Spree.t(:say_no) %></td>
         <td class="align-center"><%=tax_rate.show_rate_in_label? ? Spree.t(:say_yes) : Spree.t(:say_no) %></td>

backend/spec/features/admin/configuration/tax_rates_spec.rb

@@ -12,7 +12,7 @@
 
   # Regression test for https://github.com/spree/spree/issues/535
   it "can see a tax rate in the list if the tax category has been deleted" do
-    tax_rate.tax_category.update_column(:deleted_at, Time.current)
+    tax_rate.tax_categories.first.update_column(:deleted_at, Time.current)
     click_link "Tax Rates"
 
     expect(find("table tbody td:nth-child(3)")).to have_content('N/A')

backend/spec/features/admin/orders/adjustments_spec.rb

@@ -5,7 +5,7 @@
 
   let!(:ship_address) { create(:address) }
   let!(:tax_zone) { create(:global_zone) } # will include the above address
-  let!(:tax_rate) { create(:tax_rate, amount: 0.20, zone: tax_zone, tax_category: tax_category) }
+  let!(:tax_rate) { create(:tax_rate, amount: 0.20, zone: tax_zone, tax_categories: [tax_category]) }
 
   let!(:order) do
     create(

core/app/models/spree/calculator/default_tax.rb

@@ -9,7 +9,7 @@ class Calculator::DefaultTax < Calculator
     # Orders created with Spree 2.2 and after, have them applied to the line items individually.
     def compute_order(order)
       matched_line_items = order.line_items.select do |line_item|
-        line_item.tax_category == rate.tax_category
+        rate.tax_categories.include?(line_item.tax_category)
       end
 
       line_items_total = matched_line_items.sum(&:discounted_amount)

core/app/models/spree/tax/shipping_rate_taxer.rb

@@ -23,7 +23,7 @@ def tax(shipping_rate)
 
       def tax_rates_for_shipping_rate(shipping_rate)
         applicable_rates(shipping_rate.order).select do |tax_rate|
-          tax_rate.tax_category == shipping_rate.tax_category
+          tax_rate.tax_categories.include?(shipping_rate.tax_category)
         end
       end
     end

core/app/models/spree/tax/tax_helpers.rb

@@ -17,9 +17,9 @@ module TaxHelpers
       #
       # For further discussion, see https://github.com/spree/spree/issues/4397 and https://github.com/spree/spree/issues/4327.
       def applicable_rates(order)
-        order_zone_tax_category_ids = rates_for_order(order).map(&:tax_category_id)
+        order_zone_tax_category_ids = rates_for_order(order).flat_map(&:tax_categories).map(&:id)
         default_rates_with_unmatched_tax_category = rates_for_default_zone.to_a.delete_if do |default_rate|
-          order_zone_tax_category_ids.include?(default_rate.tax_category_id)
+          (order_zone_tax_category_ids & default_rate.tax_categories.map(&:id)).any?
         end
 
         (rates_for_order(order) + default_rates_with_unmatched_tax_category).uniq
@@ -38,7 +38,9 @@ def sum_of_included_tax_rates(item)
       end
 
       def rates_for_item(item)
-        applicable_rates(item.order).select { |rate| rate.tax_category_id == item.tax_category_id }
+        applicable_rates(item.order).select do |rate|
+          rate.tax_categories.map(&:id).include?(item.tax_category_id)
+        end
       end
     end
   end

core/app/models/spree/tax_category.rb

@@ -4,7 +4,15 @@ class TaxCategory < Spree::Base
     validates :name, presence: true
     validates_uniqueness_of :name, unless: :deleted_at
 
-    has_many :tax_rates, dependent: :destroy, inverse_of: :tax_category
+    has_many :tax_rate_tax_categories,
+      class_name: Spree::TaxRateTaxCategory,
+      dependent: :destroy,
+      inverse_of: :tax_category
+    has_many :tax_rates,
+      through: :tax_rate_tax_categories,
+      class_name: Spree::TaxRate,
+      inverse_of: :tax_categories
+
     after_save :ensure_one_default
 
     def self.default

core/app/models/spree/tax_rate.rb

@@ -9,13 +9,20 @@ class TaxRate < Spree::Base
     include Spree::AdjustmentSource
 
     belongs_to :zone, class_name: "Spree::Zone", inverse_of: :tax_rates
-    belongs_to :tax_category, class_name: "Spree::TaxCategory", inverse_of: :tax_rates
+
+    has_many :tax_rate_tax_categories,
+      class_name: Spree::TaxRateTaxCategory,
+      dependent: :destroy,
+      inverse_of: :tax_rate
+    has_many :tax_categories,
+      through: :tax_rate_tax_categories,
+      class_name: Spree::TaxCategory,
+      inverse_of: :tax_rates
 
     has_many :adjustments, as: :source
     has_many :shipping_rate_taxes, class_name: "Spree::ShippingRateTax"
 
     validates :amount, presence: true, numericality: true
-    validates :tax_category_id, presence: true
 
     # Finds all tax rates whose zones match a given address
     scope :for_address, ->(address) { joins(:zone).merge(Spree::Zone.for_address(address)) }
@@ -94,10 +101,12 @@ def compute_amount(item)
     private
 
     def adjustment_label(amount)
-      Spree.t translation_key(amount),
-              scope: "adjustment_labels.tax_rates",
-              name: name.presence || tax_category.name,
-              amount: amount_for_adjustment_label
+      Spree.t(
+        translation_key(amount),
+        scope: "adjustment_labels.tax_rates",
+        name: name.presence || tax_categories.map(&:name).join(", "),
+        amount: amount_for_adjustment_label
+      )
     end
 
     def amount_for_adjustment_label

core/app/models/spree/tax_rate_tax_category.rb

@@ -0,0 +1,6 @@
+module Spree
+  class TaxRateTaxCategory < Spree::Base
+    belongs_to :tax_rate, class_name: Spree::TaxRate, inverse_of: :tax_rate_tax_categories
+    belongs_to :tax_category, class_name: Spree::TaxCategory, inverse_of: :tax_rate_tax_categories
+  end
+end

core/db/migrate/20170412103617_transform_tax_rate_category_relation.rb

@@ -0,0 +1,48 @@
+class TransformTaxRateCategoryRelation < ActiveRecord::Migration[5.0]
+  class TaxRate < ActiveRecord::Base
+    self.table_name = "spree_tax_rates"
+  end
+
+  class TaxRateTaxCategory < ActiveRecord::Base
+    self.table_name = "spree_tax_rate_tax_categories"
+  end
+
+  def up
+    create_table :spree_tax_rate_tax_categories do |t|
+      t.integer :tax_category_id, index: true, null: false
+      t.integer :tax_rate_id, index: true, null: false
+    end
+
+    add_foreign_key :spree_tax_rate_tax_categories, :spree_tax_categories, column: :tax_category_id
+    add_foreign_key :spree_tax_rate_tax_categories, :spree_tax_rates, column: :tax_rate_id
+
+    TaxRate.where.not(tax_category_id: nil).find_each do |tax_rate|
+      TaxRateTaxCategory.create!(
+        tax_rate_id: tax_rate.id,
+        tax_category_id: tax_rate.tax_category_id
+      )
+    end
+
+    remove_column :spree_tax_rates, :tax_category_id
+  end
+
+  def down
+    add_column :spree_tax_rates, :tax_category_id, :integer, index: true
+    add_foreign_key :spree_tax_rates, :spree_tax_categories, column: :tax_category_id
+
+    TaxRate.find_each do |tax_rate|
+      tax_category_ids = TaxRateTaxCategory.where(tax_rate_id: tax_rate.id).pluck(:tax_category_id)
+
+      tax_category_ids.each_with_index do |category_id, i|
+        if i.zero?
+          tax_rate.update!(tax_category_id: category_id)
+        else
+          new_tax_rate = tax_rate.dup
+          new_tax_rate.update!(tax_category_id: category_id)
+        end
+      end
+    end
+
+    drop_table :spree_tax_rate_tax_categories
+  end
+end

core/lib/spree/testing_support/factories/adjustment_factory.rb

@@ -29,7 +29,11 @@
       after(:create) do |adjustment|
         # Set correct tax category, so that adjustment amount is not 0
         if adjustment.adjustable.is_a?(Spree::LineItem)
-          adjustment.source.tax_category = adjustment.adjustable.tax_category
+          if adjustment.adjustable.tax_category.present?
+            adjustment.source.tax_categories = [adjustment.adjustable.tax_category]
+          else
+            adjustment.source.tax_categories = []
+          end
           adjustment.source.save
           adjustment.update!
         end

core/lib/spree/testing_support/factories/tax_rate_factory.rb

@@ -6,7 +6,7 @@
   factory :tax_rate, class: Spree::TaxRate do
     zone
     amount 0.1
-    tax_category
     association(:calculator, factory: :default_tax_calculator)
+    tax_categories { [build(:tax_category)] }
   end
 end

core/spec/lib/spree/core/price_migrator_spec.rb

@@ -55,7 +55,7 @@
         name: "German reduced VAT",
         included_in_price: true,
         amount: 0.07,
-        tax_category: books_category,
+        tax_categories: [books_category],
         zone: eu_zone
       )
     end
@@ -65,7 +65,7 @@
         name: "German VAT",
         included_in_price: true,
         amount: 0.19,
-        tax_category: normal_category,
+        tax_categories: [normal_category],
         zone: eu_zone
       )
     end
@@ -75,7 +75,7 @@
         name: "German VAT",
         included_in_price: true,
         amount: 0.19,
-        tax_category: digital_category,
+        tax_categories: [digital_category],
         zone: germany_zone
       )
     end
@@ -85,7 +85,7 @@
         name: "Romanian VAT",
         included_in_price: true,
         amount: 0.24,
-        tax_category: digital_category,
+        tax_categories: [digital_category],
         zone: romania_zone
       )
     end

core/spec/lib/spree/core/testing_support/factories/order_factory_spec.rb

@@ -79,7 +79,7 @@
     context 'when shipments should be taxed' do
       let!(:ship_address) { create(:address) }
       let!(:tax_zone) { create(:global_zone) } # will include the above address
-      let!(:tax_rate) { create(:tax_rate, amount: 0.10, zone: tax_zone, tax_category: tax_category) }
+      let!(:tax_rate) { create(:tax_rate, amount: 0.10, zone: tax_zone, tax_categories: [tax_category]) }
 
       let(:tax_category) { create(:tax_category) }
       let(:shipping_method) { create(:shipping_method, tax_category: tax_category, zones: [tax_zone]) }

core/spec/models/spree/calculator/default_tax_spec.rb

@@ -6,7 +6,7 @@
   let!(:zone) { create(:zone, name: "Country Zone", default_tax: default_tax, countries: [tax_rate_country]) }
   let(:tax_rate_country) { address.country }
   let(:tax_category) { create(:tax_category) }
-  let!(:rate) { create(:tax_rate, tax_category: tax_category, amount: 0.05, included_in_price: included_in_price, zone: zone) }
+  let!(:rate) { create(:tax_rate, tax_categories: [tax_category], amount: 0.05, included_in_price: included_in_price, zone: zone) }
   let(:included_in_price) { false }
   let(:default_tax) { false }
   subject(:calculator) { Spree::Calculator::DefaultTax.new(calculable: rate ) }

core/spec/models/spree/order/checkout_spec.rb

@@ -184,7 +184,7 @@ def assert_state_changed(order, from, to)
 
       it "recalculates tax and updates totals" do
         zone = create(:zone, countries: [order.tax_address.country])
-        create(:tax_rate, tax_category: line_item.tax_category, amount: 0.05, zone: zone)
+        create(:tax_rate, tax_categories: [line_item.tax_category], amount: 0.05, zone: zone)
         order.next!
         expect(order).to have_attributes(
           adjustment_total: 0.5,

core/spec/models/spree/order_capturing_spec.rb

@@ -38,7 +38,7 @@
 
       let!(:product) { create(:product, price: 10.00) }
       let!(:variant) do
-        create(:variant, price: 10, product: product, track_inventory: false, tax_category: tax_rate.tax_category)
+        create(:variant, price: 10, product: product, track_inventory: false, tax_category: tax_rate.tax_categories.first)
       end
       let!(:shipping_method) { create(:free_shipping_method) }
       let(:tax_rate) { create(:tax_rate, amount: 0.1, zone: create(:global_zone, name: "Some Tax Zone")) }

core/spec/models/spree/order_contents_spec.rb

@@ -123,7 +123,7 @@
     describe 'tax calculations' do
       let!(:zone) { create(:global_zone) }
       let!(:tax_rate) do
-        create(:tax_rate, zone: zone, tax_category: variant.tax_category)
+        create(:tax_rate, zone: zone, tax_categories: [variant.tax_category])
       end
 
       context 'when the order has a taxable address' do

core/spec/models/spree/order_updater_spec.rb

@@ -273,7 +273,7 @@ def create_adjustment(label, amount)
       describe 'tax recalculation' do
         let!(:ship_address) { create(:address) }
         let!(:tax_zone) { create(:global_zone) } # will include the above address
-        let!(:tax_rate) { create(:tax_rate, zone: tax_zone, tax_category: tax_category) }
+        let!(:tax_rate) { create(:tax_rate, zone: tax_zone, tax_categories: [tax_category]) }
 
         let(:order) do
           create(

core/spec/models/spree/price_spec.rb

@@ -133,7 +133,7 @@
   describe 'net_amount' do
     let(:country) { create(:country, iso: "DE") }
     let(:zone) { create(:zone, countries: [country]) }
-    let!(:tax_rate) { create(:tax_rate, included_in_price: true, zone: zone, tax_category: variant.tax_category) }
+    let!(:tax_rate) { create(:tax_rate, included_in_price: true, zone: zone, tax_categories: [variant.tax_category]) }
 
     let(:variant) { create(:product).master }
 

core/spec/models/spree/promotion_handler/coupon_spec.rb

@@ -255,7 +255,7 @@ def expect_adjustment_creation(adjustable:, promotion:, promotion_code:nil)
           let(:order) { create(:order, store: store) }
           let(:tax_category) { create(:tax_category, name: "Taxable Foo") }
           let(:zone) { create(:zone, :with_country) }
-          let!(:tax_rate) { create(:tax_rate, amount: 0.1, tax_category: tax_category, zone: zone )}
+          let!(:tax_rate) { create(:tax_rate, amount: 0.1, tax_categories: [tax_category], zone: zone ) }
 
           before(:each) do
             expect(order).to receive(:tax_address).at_least(:once).and_return(Spree::Tax::TaxLocation.new(country: zone.countries.first))

core/spec/models/spree/shipment_spec.rb

@@ -130,7 +130,7 @@
 
     let!(:ship_address) { create(:address) }
     let!(:tax_zone) { create(:global_zone) } # will include the above address
-    let!(:tax_rate) { create(:tax_rate, amount: 0.1, zone: tax_zone, tax_category: tax_category) }
+    let!(:tax_rate) { create(:tax_rate, amount: 0.1, zone: tax_zone, tax_categories: [tax_category]) }
     let(:tax_category) { create(:tax_category) }
     let(:variant) { create(:variant, tax_category: tax_category) }
 
@@ -548,7 +548,7 @@
   context "changes shipping rate via general update" do
     let!(:ship_address) { create(:address) }
     let!(:tax_zone) { create(:global_zone) } # will include the above address
-    let!(:tax_rate) { create(:tax_rate, amount: 0.10, zone: tax_zone, tax_category: tax_category) }
+    let!(:tax_rate) { create(:tax_rate, amount: 0.10, zone: tax_zone, tax_categories: [tax_category]) }
     let(:tax_category) { create(:tax_category) }
 
     let(:order) do