Added the :selected option with the default tax category #12989

app/controllers/spree/admin/products_controller.rb

@@ -11,6 +11,7 @@ class ProductsController < ::Admin::ResourceController
       include OrderCyclesHelper
       include EnterprisesHelper
       helper ::Admin::ProductsHelper
+      helper Spree::Admin::TaxCategoriesHelper
 
       before_action :load_data
       before_action :load_producers, only: [:index, :new]

app/helpers/spree/admin/tax_categories_helper.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module Spree
+  module Admin
+    module TaxCategoriesHelper
+      def tax_category_dropdown_options(require_tax_category)
+        if require_tax_category
+          {
+            include_blank: false,
+            selected: Spree::TaxCategory.find_by(is_default: true)&.id
+          }
+        else
+          {
+            include_blank: t(:none),
+          }
+        end
+      end
+    end
+  end
+end

app/views/spree/admin/products/_tax_category_form.html.haml

@@ -1,5 +1,5 @@
 = f.field_container :tax_category_id do
   = f.label :tax_category_id, t(:tax_category)
   %br
-  = f.collection_select(:tax_category_id, Spree::TaxCategory.all, :id, :name, {:include_blank => Spree::Config.products_require_tax_category ? false : t(:none)}, {:class => "select2 fullwidth"})
+  = f.collection_select(:tax_category_id, Spree::TaxCategory.all, :id, :name, tax_category_dropdown_options(Spree::Config.products_require_tax_category), {:class => "select2 fullwidth"})
   = f.error_message_on :tax_category_id

spec/helpers/spree/admin/tax_categories_helper_spec.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+RSpec.describe Spree::Admin::TaxCategoriesHelper do
+  describe '#tax_category_dropdown_options' do
+    let!(:default_tax_category) { create(:tax_category, is_default: true) }
+    let!(:other_tax_category) { create(:tax_category, is_default: false) }
+
+    context 'when products require a tax category' do
+      it 'returns include_blank as false' do
+        options = helper.tax_category_dropdown_options(true)
+        expect(options[:include_blank]).to eq(false)
+      end
+
+      it 'returns the default tax category as selected' do
+        options = helper.tax_category_dropdown_options(true)
+        expect(options[:selected]).to eq(default_tax_category.id)
+      end
+
+      context 'when no default tax category exists' do
+        before { default_tax_category.update(is_default: false) }
+
+        it 'returns nil for the selected value' do
+          options = helper.tax_category_dropdown_options(true)
+          expect(options[:selected]).to be_nil
+        end
+      end
+    end
+
+    context 'when products do not require a tax category' do
+      it 'returns include_blank as the translated "none" string' do
+        options = helper.tax_category_dropdown_options(false)
+        expect(options[:include_blank]).to eq("None")
+      end
+
+      it 'does not include a selected tax category' do
+        options = helper.tax_category_dropdown_options(false)
+        expect(options[:selected]).to be_nil
+      end
+    end
+  end
+end