Introducing product brand using taxon_brand_selector

core/app/models/spree/product.rb

@@ -291,6 +291,10 @@ def gallery
       @gallery ||= Spree::Config.product_gallery_class.new(self)
     end
 
+    def brand
+      Spree::Config.brand_selector_class.new(self).call
+    end
+
     private
 
     def any_variants_not_track_inventory?

core/app/models/spree/taxon_brand_selector.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+module Spree
+  class TaxonBrandSelector
+    BRANDS_TAXONOMY_NAME = "Brands"
+
+    def initialize(product)
+      @product = product
+    end
+
+    def call
+      product.taxons
+             .joins(:taxonomy)
+             .where(spree_taxonomies: { name: BRANDS_TAXONOMY_NAME })
+             .first
+    end
+
+    private
+
+    attr_reader :product
+  end
+end

core/config/locales/en.yml

@@ -1075,6 +1075,8 @@ en:
     billing: Billing
     billing_address: Billing Address
     both: Both
+    brand: Brand
+    brands: Brands
     calculated_reimbursements: Calculated Reimbursements
     calculator: Calculator
     calculator_settings_warning: If you are changing the calculator type or preference source, you must save first before you can edit the calculator settings

core/lib/spree/app_configuration.rb

@@ -522,6 +522,13 @@ def payment_canceller
     #   Spree::StoreCreditPrioritizer.
     class_name_attribute :store_credit_prioritizer_class, default: 'Spree::StoreCreditPrioritizer'
 
+    # Allows finding brand for product.
+    #
+    # @!attribute [rw] brand_selector_class
+    # @return [Class] a class with the same public interfaces as
+    #   Spree::TaxonBrandSelector.
+    class_name_attribute :brand_selector_class, default: 'Spree::TaxonBrandSelector'
+
     # @!attribute [rw] taxon_image_style_default
     #
     # Defines which style to default to when style is not provided

core/spec/models/spree/taxon_brand_selector_spec.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Spree::TaxonBrandSelector, type: :model do
+  let(:taxonomy) { create(:taxonomy, name: "Brands") }
+  let(:taxon) { create(:taxon, taxonomy: taxonomy, name: "Brand A") }
+  let(:product) { create(:product, taxons: [taxon]) }
+
+  subject { described_class.new(product) }
+
+  describe "#call" do
+    context "when the product has a taxon under the 'Brands' taxonomy" do
+      it "returns the first taxon under 'Brands'" do
+        expect(subject.call).to eq(taxon)
+      end
+    end
+
+    context "when the product has multiple taxons under the 'Brands' taxonomy" do
+      let(:taxon_b) { create(:taxon, taxonomy: taxonomy, name: "Brand B") }
+      before { product.taxons << taxon_b }
+
+      it "returns the first taxon under 'Brands'" do
+        expect(subject.call).to eq(taxon)
+      end
+    end
+
+    context "when the product does not have a taxon under the 'Brands' taxonomy" do
+      let(:other_taxonomy) { create(:taxonomy, name: "Categories") }
+      let(:other_taxon) { create(:taxon, taxonomy: other_taxonomy, name: "Category A") }
+      let(:product) { create(:product, taxons: [other_taxon]) }
+
+      it "returns nil" do
+        expect(subject.call).to be_nil
+      end
+    end
+
+    context "when the product has no taxons" do
+      let(:product) { create(:product) }
+
+      it "returns nil" do
+        expect(subject.call).to be_nil
+      end
+    end
+  end
+end

sample/db/samples/taxons.rb

@@ -4,6 +4,7 @@
 Spree::Sample.load_sample("products")
 
 categories = Spree::Taxonomy.find_by!(name: "Categories")
+brands = Spree::Taxonomy.find_by!(name: "Brands")
 
 products = {
   solidus_bottles: "Solidus Water Bottle",
@@ -29,6 +30,29 @@
     name: "Categories",
     taxonomy: categories,
   },
+  {
+    name: "Brands",
+    taxonomy: brands
+  },
+  {
+    name: "Solidus",
+    taxonomy: brands,
+    parent: "Brands",
+    products: [
+      products[:solidus_tote],
+      products[:solidus_hoodie],
+      products[:solidus_mug_set],
+      products[:solidus_hat],
+      products[:solidus_sticker],
+      products[:solidus_notebook],
+      products[:solidus_tshirt],
+      products[:solidus_long_sleeve_tee],
+      products[:solidus_dark_tee],
+      products[:solidus_bottles],
+      products[:solidus_canvas_tote],
+      products[:solidus_cap]
+    ]
+  },
   {
     name: "Clothing",
     taxonomy: categories,