Add a generator for Google Merchant (XML)

As specified in https://support.google.com/merchants/answer/7052112.

This also adds global configuration attributes to be used in the store
feed.

Co-Authored-By: Flavio Auciello <[email protected]>
Co-Authored-By: Elia Schito <[email protected]>

lib/solidus_feeds.rb

@@ -8,3 +8,5 @@
 require 'solidus_feeds/engine'
 
 require 'solidus_feeds/publishers/s3'
+
+require 'solidus_feeds/generators/google_merchant'

lib/solidus_feeds/configuration.rb

@@ -24,6 +24,8 @@ def feeds
   end
 
   class << self
+    attr_writer :title, :link, :description, :language
+
     def configuration
       @configuration ||= Configuration.new
     end
@@ -37,5 +39,21 @@ def reset_config!
     def configure
       yield configuration
     end
+
+    def title
+      @title ||= Spree::Store.default.name
+    end
+
+    def link
+      @link ||= "https://#{Spree::Store.default.url}"
+    end
+
+    def description
+      @description ||= "Find out about new products on https://#{Spree::Store.default.url} first!"
+    end
+
+    def language
+      @language ||= 'en-us'
+    end
   end
 end

lib/solidus_feeds/generators/google_merchant.rb

@@ -0,0 +1,106 @@
+# frozen_string_literal: true
+
+require 'builder'
+
+module SolidusFeeds
+  module Generators
+    # The GoogleMerchant XML feed as described in https://support.google.com/merchants/answer/7052112.
+    class GoogleMerchant
+      attr_accessor :products, :host
+
+      def initialize(products, host:)
+        self.products = products
+        self.host = host
+      end
+
+      def call(io)
+        builder = Builder::XmlMarkup.new(target: io, indent: 0)
+        render_template(builder)
+      end
+
+      def render_template(xml)
+        xml.rss version: "2.0", "xmlns:g" => "http://base.google.com/ns/1.0" do
+          xml.channel do
+            xml.title SolidusFeeds.title
+            xml.link SolidusFeeds.link
+            xml.description SolidusFeeds.description
+            xml.language SolidusFeeds.language
+            products.find_each do |product|
+              xml.item do
+                xml.tag! 'g:id', id(product)
+                xml.tag! 'g:title', title(product)
+                xml.tag! 'g:description', description(product)
+                xml.tag! 'g:link', link(product)
+                xml.tag! 'g:image_link', image_link(product)
+                xml.tag! 'g:condition', condition(product)
+                xml.tag! 'g:price', price(product)
+                xml.tag! 'g:availability', availability(product)
+                xml.tag! 'g:brand', brand(product)
+                xml.tag! 'g:mpn', mpn(product)
+                xml.tag! 'g:google_product_category', google_product_category_id(product)
+              end
+            end
+          end
+        end
+      end
+
+      def id(product)
+        product.id
+      end
+
+      def title(product)
+        product.name
+      end
+
+      def description(product)
+        product.description
+      end
+
+      def link(product)
+        spree_routes.product_url(product, host: host)
+      end
+
+      def image_link(product)
+        return unless product.images.any?
+
+        attachment_url = product.images.first.attachment.url(:large)
+        asset_host = ActionController::Base.asset_host
+
+        URI.join(asset_host, attachment_url).to_s
+      end
+
+      # Must be "new", "refurbished", or "used".
+      def condition(product)
+        product.property("condition") || "new"
+      end
+
+      def price(product)
+        Spree::Money.new(product.price).money.format(symbol: false, with_currency: true)
+      end
+
+      # Must be "in stock", "preorder" or "out of stock"
+      def availability(product)
+        product.master.in_stock? ? 'in stock' : 'out of stock'
+      end
+
+      def brand(product)
+        product.property("brand") || SolidusFeeds.title
+      end
+
+      def mpn(product)
+        product.master.sku
+      end
+
+      def google_product_category_id(product)
+        # Must be selected from https://support.google.com/merchants/answer/1705911
+        product.property("google_product_category_id")
+      end
+
+      private
+
+      def spree_routes
+        @spree_routes ||= Spree::Core::Engine.routes.url_helpers
+      end
+    end
+  end
+end

spec/lib/solidus_feeds/generators/google_merchant_spec.rb

@@ -0,0 +1,132 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require 'stringio'
+
+RSpec.describe SolidusFeeds::Generators::GoogleMerchant do
+  subject(:generator) { described_class.new(products, host: 'https://example.com') }
+
+  let(:products) do
+    Spree::Product.where(id: [
+      create(:product, id: 123, slug: 'pro1', name: 'A product', price: 123.45, description: 'product description', sku: 'PRD1'), # rubocop:disable Layout/LineLength
+      create(:product, id: 456, slug: 'pro2', name: 'Another product', price: 678.90, description: 'another product description', sku: 'PRD2'), # rubocop:disable Layout/LineLength
+    ]).order(:id)
+  end
+  let(:product) { products.first }
+  let(:store) { instance_double(Spree::Store, name: "The Best Store", url: "example.com") }
+
+  before { allow(Spree::Store).to receive(:default).and_return(store) }
+
+  before(:each, with_images: true) do
+    allow(ActionController::Base).to receive(:asset_host).and_return('https://assets.example.com')
+    Spree::Image.create! viewable: products.first.master, attachment_file_name: 'foo.png', id: 234
+  end
+
+  describe '#call', :with_images do
+    describe 'generated XML' do
+      def expect_xml_content(xpath)
+        expect(xml.xpath(xpath, 'g' => "http://base.google.com/ns/1.0").text)
+      end
+
+      let(:xml) do
+        io = StringIO.new
+        generator.call(io)
+        Nokogiri::XML(io.string)
+      end
+
+      it 'includes the tags with the expected values' do
+        aggregate_failures do
+          expect_xml_content('//channel/title').to eq('The Best Store')
+          expect_xml_content('//channel/link').to eq('https://example.com')
+          expect_xml_content('//channel/description').to eq('Find out about new products on https://example.com first!')
+          expect_xml_content('//channel/language').to eq('en-us')
+          expect_xml_content('//channel/item[1]/g:id').to eq('123')
+          expect_xml_content('//channel/item[1]/g:title').to eq('A product')
+          expect_xml_content('//channel/item[1]/g:description').to eq('product description')
+          expect_xml_content('//channel/item[1]/g:link').to eq('https://example.com/products/pro1')
+          expect_xml_content('//channel/item[1]/g:image_link').to eq("https://assets.example.com/spree/products/234/large/foo.png") # rubocop:disable Layout/LineLength
+          expect_xml_content('//channel/item[1]/g:condition').to eq('new')
+          expect_xml_content('//channel/item[1]/g:price').to eq('123.45 USD')
+          expect_xml_content('//channel/item[1]/g:availability').to eq('out of stock')
+          expect_xml_content('//channel/item[1]/g:brand').to eq('The Best Store')
+          expect_xml_content('//channel/item[1]/g:mpn').to eq('PRD1')
+          expect_xml_content('//channel/item[1]/g:google_product_category').to eq('')
+        end
+      end
+    end
+  end
+
+  specify '#id' do
+    product = instance_double(Spree::Product, id: 789)
+
+    expect(generator.id(product)).to eq(789)
+  end
+
+  specify '#title' do
+    product = instance_double(Spree::Product, name: "Foo Bar")
+
+    expect(generator.title(product)).to eq("Foo Bar")
+  end
+
+  specify '#description' do
+    product = instance_double(Spree::Product, description: "Foo Bar")
+
+    expect(generator.description(product)).to eq("Foo Bar")
+  end
+
+  specify '#link' do
+    product = instance_double(Spree::Product, to_param: "123-my-product")
+
+    expect(generator.link(product)).to eq("https://example.com/products/123-my-product")
+  end
+
+  specify '#image_link', :with_images do
+    expect(generator.image_link(products.first)).to eq("https://assets.example.com/spree/products/234/large/foo.png")
+    expect(generator.image_link(products.second)).to eq(nil)
+  end
+
+  specify '#condition' do
+    products.first.set_property("condition", "foo-bar")
+
+    expect(generator.condition(product)).to eq("foo-bar")
+  end
+
+  specify '#price' do
+    product = instance_double(Spree::Product, price: 321.45);
+
+    expect(generator.price(product)).to eq("321.45 USD")
+  end
+
+  describe '#availability' do
+    it 'is "in stock" when available' do
+      allow(product.master).to receive(:in_stock?).and_return(true)
+
+      expect(generator.availability(product)).to eq("in stock")
+    end
+
+    it 'is "out of stock" when unavailable' do
+      allow(product.master).to receive(:in_stock?).and_return(false)
+
+      expect(generator.availability(product)).to eq("out of stock")
+    end
+  end
+
+  specify '#brand' do
+    product.set_property("brand", "foo-bar")
+
+    expect(generator.brand(product)).to eq("foo-bar")
+    expect(generator.brand(products.second)).to eq("The Best Store")
+  end
+
+  specify '#mpn' do
+    allow(product.master).to receive(:sku).and_return("FOOO_123_SKU")
+
+    expect(generator.mpn(product)).to eq("FOOO_123_SKU")
+  end
+
+  specify '#google_product_category_id' do
+    product.set_property("google_product_category_id", "123456")
+
+    expect(generator.google_product_category_id(product)).to eq("123456")
+  end
+end

spec/lib/solidus_feeds/solidus_feeds_spec.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+RSpec.describe SolidusFeeds do
+  let(:store) { instance_double(Spree::Store, name: "The Best Store", url: "example.com") }
+
+  before { allow(Spree::Store).to receive(:default).and_return(store) }
+
+  specify '.title' do
+    expect(described_class.title).to eq("The Best Store")
+  end
+
+  specify '.link' do
+    expect(described_class.link).to eq("https://example.com")
+  end
+
+  specify '.description' do
+    expect(described_class.description).to eq("Find out about new products on https://example.com first!")
+  end
+
+  specify '.language' do
+    expect(described_class.language).to eq("en-us")
+  end
+end