fix(kit_creation): Refactor kit value calculation and update logic

Author: Olexii Kasianenko

app/models/kit.rb

@@ -55,6 +55,13 @@ def reactivate
     item.update!(active: true)
   end
 
+  def update_value_in_cents
+    kit_value_in_cents = line_items.includes(:item).reduce(0) do |sum, line_item|
+      sum + line_item.item.value_in_cents.to_i * line_item.quantity.to_i
+    end
+    update!(value_in_cents: kit_value_in_cents)
+  end
+
   private
 
   def at_least_one_item

app/services/item_update_service.rb

@@ -26,9 +26,6 @@ def call
   def update_kit_value
     return unless item.kit
 
-    kit_value_in_cents = item.kit.items.reduce(0) do |sum, i|
-      sum + i.value_in_cents.to_i * item.kit.line_items.find_by(item_id: i.id).quantity.to_i
-    end
-    item.kit.update!(value_in_cents: kit_value_in_cents)
+    item.kit.update_value_in_cents
   end
 end

app/services/kit_create_service.rb

@@ -43,11 +43,8 @@ def call
       unless item_creation_result.success?
         raise item_creation_result.error
       end
-      kit.items.update_all(visible_to_partners: kit.visible_to_partners)
-      kit_value_in_cents = kit.items.reduce(0) do |sum, i|
-        sum + i.value_in_cents.to_i * kit.line_items.find_by(item_id: i.id).quantity.to_i
-      end
-      kit.update!(value_in_cents: kit_value_in_cents)
+      kit.item.update(visible_to_partners: kit.visible_to_partners)
+      kit.update_value_in_cents
     rescue StandardError => e
       errors.add(:base, e.message)
       raise ActiveRecord::Rollback

spec/services/item_update_service_spec.rb

@@ -8,7 +8,7 @@
 
     let(:kit) { create(:kit) }
     let(:item) { create(:item, kit: kit) }
-    let(:item2) { create(:item, kit: kit) }
+    let(:line_item) { create(:line_item, item: item, quantity: 1) }
     let(:params) do
       {
         name: "Updated Item Name",
@@ -17,11 +17,9 @@
       }
     end
     let(:request_unit_ids) { [] }
-    let(:kit_value_in_cents) do
-      kit.line_items.reduce(0) do |sum, li|
-        item = Item.find(li.item_id)
-        sum + item.value_in_cents.to_i * li.quantity.to_i
-      end
+
+    before do
+      kit.line_items = [line_item]
     end
 
     context "params are ok" do
@@ -42,7 +40,7 @@
       it "updates the kit value_in_cents" do
         subject
         kit.reload
-        expect(kit.value_in_cents).to eq(kit_value_in_cents)
+        expect(kit.value_in_cents).to eq(params[:value_in_cents])
       end
     end