Fix Spree::Shipment#item_cost for split shipments

api/app/views/spree/api/shipments/_small.json.jbuilder

@@ -23,7 +23,7 @@ json.cache! [I18n.locale, shipment] do
       json.(shipping_category, :id, :name)
     end
   end
-  json.manifest(shipment.manifest) do |manifest_item|
+  json.manifest(shipment.shipping_manifest_items) do |manifest_item|
     json.variant_id manifest_item.variant.id
     json.quantity(manifest_item.quantity)
     json.states(manifest_item.states)

api/app/views/spree/api/shipments/show.json.jbuilder

@@ -23,7 +23,7 @@ json.cache! [I18n.locale, @shipment] do
       json.(shipping_category, :id, :name)
     end
   end
-  json.manifest(@shipment.manifest) do |manifest_item|
+  json.manifest(@shipment.shipping_manifest_items) do |manifest_item|
     json.variant do
       json.partial!("spree/api/variants/small", variant: manifest_item.variant)
     end

backend/app/views/spree/admin/orders/confirm/_shipment_manifest.html.erb

@@ -1,4 +1,4 @@
-<% shipment.manifest.each do |item| %>
+<% shipment.shipping_manifest_items.each do |item| %>
   <tr class="stock-item" data-item-quantity="<%= item.quantity %>">
     <td class="item-image">
       <%= render 'spree/admin/shared/image',

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

@@ -337,7 +337,7 @@
             visit spree.edit_admin_order_path(order)
 
             expect(order.shipments.count).to eq(1)
-            expect(order.shipments.first.manifest.count).to eq(2)
+            expect(order.shipments.first.shipping_manifest_items.count).to eq(2)
 
             within('tr', text: line_item.sku) { click_icon 'arrows-h' }
             complete_split_to(stock_location2)

core/app/mailers/spree/carton_mailer.rb

@@ -18,7 +18,7 @@ class CartonMailer < BaseMailer
     def shipped_email(options, _deprecated_options = {})
       @order = options.fetch(:order)
       @carton = options.fetch(:carton)
-      @manifest = @carton.manifest_for_order(@order)
+      @shipping_manifest_for_order = @carton.manifest_for_order(@order)
       options = { resend: false }.merge(options)
       @store = @order.store
       subject = (options[:resend] ? "[#{t('spree.resend').upcase}] " : '')

core/app/models/spree/carton.rb

@@ -45,15 +45,27 @@ def display_shipped_at
     shipped_at.to_s(:rfc822)
   end
 
-  def manifest
-    @manifest ||= Spree::ShippingManifest.new(inventory_units: inventory_units).items
+  def shipping_manifest_items
+    @shipping_manifest_items ||= shipping_manifest.items
   end
 
-  def manifest_for_order(order)
-    Spree::ShippingManifest.new(inventory_units: inventory_units).for_order(order).items
+  alias manifest shipping_manifest_items
+  deprecate manifest: :shipping_manifest_items, deprecator: Spree::Deprecation
+
+  def shipping_manifest_for_order(order)
+    shipping_manifest.for_order(order).items
   end
 
+  alias manifest_for_order shipping_manifest_for_order
+  deprecate manifest_for_order: :shipping_manifest_for_order, deprecator: Spree::Deprecation
+
   def any_exchanges?
     inventory_units.any?(&:original_return_item)
   end
+
+  private
+
+  def shipping_manifest
+    @shipping_manifest ||= Spree::ShippingManifest.new(inventory_units: inventory_units)
+  end
 end

core/app/models/spree/shipment.rb

@@ -109,11 +109,11 @@ def add_shipping_method(shipping_method, selected = false)
     deprecate :add_shipping_method, deprecator: Spree::Deprecation
 
     def after_cancel
-      manifest.each { |item| manifest_restock(item) }
+      shipping_manifest_items.each { |item| manifest_restock(item) }
     end
 
     def after_resume
-      manifest.each { |item| manifest_unstock(item) }
+      shipping_manifest_items.each { |item| manifest_unstock(item) }
     end
 
     def backordered?
@@ -184,7 +184,7 @@ def inventory_units_for_item(line_item, variant = nil)
     end
 
     def item_cost
-      line_items.map(&:total).sum
+      manifest.sum(&:item_cost)
     end
 
     def ready_or_pending?
@@ -228,10 +228,13 @@ def selected_shipping_rate
       shipping_rates.detect(&:selected?)
     end
 
-    def manifest
-      @manifest ||= Spree::ShippingManifest.new(inventory_units: inventory_units).items
+    def shipping_manifest_items
+      @shipping_manifest_items ||= shipping_manifest.items
     end
 
+    alias manifest shipping_manifest_items
+    deprecate manifest: :shipping_manifest_items, deprecator: Spree::Deprecation
+
     def selected_shipping_rate_id
       selected_shipping_rate.try(:id)
     end
@@ -398,6 +401,10 @@ def finalize_pending_inventory_units
       Spree::Stock::InventoryUnitsFinalizer.new(pending_units).run!
     end
 
+    def shipping_manifest
+      @shipping_manifest ||= Spree::ShippingManifest.new(inventory_units: inventory_units)
+    end
+
     def after_ship
       order.shipping.ship_shipment(self, suppress_mailer: suppress_mailer)
     end

core/app/models/spree/shipping_manifest.rb

@@ -1,7 +1,11 @@
 # frozen_string_literal: true
 
 class Spree::ShippingManifest
-  ManifestItem = Struct.new(:line_item, :variant, :quantity, :states)
+  ManifestItem = Struct.new(:line_item, :variant, :quantity, :states) do
+    def item_cost
+      (line_item.price + (line_item.adjustment_total / line_item.quantity)) * quantity
+    end
+  end
 
   def initialize(inventory_units:)
     @inventory_units = inventory_units.to_a

core/app/views/spree/carton_mailer/shipped_email.html.erb

@@ -11,7 +11,7 @@
         <%= t('spree.shipment_mailer.shipped_email.shipment_summary') %>
       </p>
       <table>
-        <% @manifest.each do |item| %>
+        <% @shipping_manifest_for_order.each do |item| %>
           <tr>
             <td><%= item.variant.sku %></td>
             <td><%= item.variant.product.name %></td>

core/app/views/spree/carton_mailer/shipped_email.text.erb

@@ -5,7 +5,7 @@
 ============================================================
 <%= t('spree.shipment_mailer.shipped_email.shipment_summary') %>
 ============================================================
-<% @manifest.each do |item| %>
+<% @shipping_manifest_for_order.each do |item| %>
   <%= item.variant.sku %> <%= item.variant.product.name %> <%= item.variant.options_text %>
 <% end %>
 ============================================================

core/spec/models/spree/carton_spec.rb

@@ -83,7 +83,16 @@
   end
 
   describe "#manifest" do
-    subject { carton.manifest }
+    it "is deprecated" do
+      Spree::Deprecation.silence do
+        expect(Spree::Deprecation).to(receive(:warn))
+        Spree::Shipment.new.manifest
+      end
+    end
+  end
+
+  describe "#shipping_manifest_items" do
+    subject { carton.shipping_manifest_items }
 
     let(:carton) { create(:carton, inventory_units: [first_order.inventory_units, second_order.inventory_units].flatten) }
     let(:first_order) { create(:order_ready_to_ship, line_items_count: 1) }
@@ -97,6 +106,15 @@
   end
 
   describe "#manifest_for_order" do
+    it "is deprecated" do
+      Spree::Deprecation.silence do
+        expect(Spree::Deprecation).to(receive(:warn))
+        Spree::Carton.new.manifest_for_order(create(:order))
+      end
+    end
+  end
+
+  describe "#shipping_manifest_for_order" do
     subject { carton.manifest_for_order(first_order) }
 
     let(:carton) { create(:carton, inventory_units: [first_order.inventory_units, second_order.inventory_units].flatten) }

core/spec/models/spree/shipment_spec.rb

@@ -141,6 +141,26 @@
     it 'should equal line items final amount with tax' do
       expect(shipment.item_cost).to eql(11.0)
     end
+
+    context 'with more shipments for the same line_item' do
+      let(:order) do
+        create(
+          :order_with_line_items,
+          line_items_attributes: [{ price: 10, variant: variant, quantity: 2 }],
+          ship_address: ship_address,
+        )
+      end
+      let(:other_shipment) { order.shipments.create(stock_location_id: shipment.stock_location) }
+
+      it 'returns shipment line items amount with tax' do
+        expect(order.shipments.first.item_cost).to eql(22.0)
+        expect {
+          order.inventory_units.last.update(shipment_id: other_shipment.id)
+        }.to change { order.shipments.reload.first.item_cost }.from(22.0).to(11.0)
+
+        expect(order.shipments.second.item_cost).to eql(11.0)
+      end
+    end
   end
 
   it "#discounted_cost" do
@@ -187,21 +207,30 @@
     expect(shipment.total).to eq(8)
   end
 
-  context "manifest" do
+  describe "#manifest_items" do
     let(:order) { create(:order) }
     let(:variant) { create(:variant) }
     let!(:line_item) { order.contents.add variant }
     let!(:shipment) { order.create_proposed_shipments.first }
 
     it "returns variant expected" do
-      expect(shipment.manifest.first.variant).to eq variant
+      expect(shipment.shipping_manifest_items.first.variant).to eq variant
     end
 
     context "variant was removed" do
       before { variant.discard }
 
       it "still returns variant expected" do
-        expect(shipment.manifest.first.variant).to eq variant
+        expect(shipment.shipping_manifest_items.first.variant).to eq variant
+      end
+    end
+  end
+
+  context "manifest" do
+    it "is deprecated" do
+      Spree::Deprecation.silence do
+        expect(Spree::Deprecation).to(receive(:warn))
+        Spree::Shipment.new.manifest
       end
     end
   end

frontend/app/views/spree/checkout/_delivery.html.erb

@@ -24,7 +24,7 @@
               <th><%= t('spree.price') %></th>
             </thead>
             <tbody>
-              <% ship_form.object.manifest.each do |item| %>
+              <% ship_form.object.shipping_manifest_items.each do |item| %>
                 <tr class="stock-item">
                   <td class="item-image">
                     <%= render 'spree/shared/image',