Replace dependency on canonical-rails with tag helper

template.rb

@@ -65,7 +65,6 @@
   end
 
   gem 'responders'
-  gem 'canonical-rails'
   gem 'solidus_support'
   gem 'truncate_html'
   gem 'view_component', '~> 3.0'
@@ -105,7 +104,6 @@
   directory 'public', 'public'
 
   copy_file 'config/initializers/solidus_auth_devise_unauthorized_redirect.rb'
-  copy_file 'config/initializers/canonical_rails.rb'
   copy_file 'config/routes/storefront.rb'
   copy_file 'config/tailwind.config.js'
   create_file 'app/assets/builds/tailwind.css'

templates/app/helpers/layout_helper.rb

@@ -0,0 +1,36 @@
+module LayoutHelper
+  # Generates a simple canonical tag based on the request path, preserving allowed
+  # parameters. For collection actions, a trailing slash is added to the href.
+  # For more advanced use cases, consider using the `canonical-rails` gem.
+  #
+  # @see https://github.com/jumph4x/canonical-rails
+  # @see https://developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls
+  #
+  # @param host [String] the host to use in the canonical URL
+  # @param collection_actions [Array<String>] the actions that will include a trailing slash
+  # @param allowed_parameters [Array<Symbol>] the parameters to preserve in the canonical URL
+  # @return [String] the generated link rel="canonical" tag
+  def simple_canonical_tag(
+    host: current_store&.url,
+    collection_actions: %w[index],
+    allowed_parameters: [:keywords, :page, :search, :taxon]
+  )
+    path_without_extension = request.path
+      .sub(/\.#{params[:format]}$/, "")
+      .sub(/\/$/, "")
+
+    href = "#{request.protocol}#{host}#{path_without_extension}"
+
+    trailing_slash = request.params.key?('action') &&
+      collection_actions.include?(request.params['action'])
+    href += '/' if trailing_slash
+
+    query_params = params.select do |key, value|
+      value.present? && allowed_parameters.include?(key.to_sym)
+    end.to_unsafe_h
+
+    href += "?#{query_params.to_query}" if query_params.present?
+
+    tag(:link, rel: :canonical, href: href)
+  end
+end

templates/app/views/layouts/storefront.html.erb

@@ -5,7 +5,7 @@
     <title><%= title %></title>
     <meta name="viewport" content="width=device-width, initial-scale=1">
     <%== meta_data_tags %>
-    <%= canonical_tag(current_store.url) %>
+    <%= simple_canonical_tag %>
     <%= csrf_meta_tags %>
 
     <%= stylesheet_link_tag "tailwind", "data-turbo-track": "reload" %>

templates/spec/system/template_rendering_spec.rb

@@ -7,14 +7,80 @@
     Capybara.ignore_hidden_elements = true
   end
 
+  let!(:taxon) {
+    taxonomy = create :taxonomy, name: "Solidus Brand"
+    create :taxon, name: "Accessories", taxonomy: taxonomy, parent: taxonomy.root
+  }
+
   before do
     Capybara.ignore_hidden_elements = false
+
+    Spree::Store.create!(
+      code: 'spree',
+      name: 'My Spree Store',
+      url: 'spreestore.example.com',
+      mail_from_address: '[email protected]',
+      default: true
+    )
   end
 
   it 'layout should have canonical tag referencing site url' do
-    Spree::Store.create!(code: 'spree', name: 'My Spree Store', url: 'spreestore.example.com', mail_from_address: '[email protected]')
-
     visit root_path
+
     expect(find('link[rel=canonical]')[:href]).to eql('http://spreestore.example.com/')
   end
+
+  it "renders a canonical tag for products index page with keywords query string" do
+    create(:product_in_stock, name: 'Solidus Mug', price: 10.00)
+
+    visit products_path(keywords: 'solidus')
+
+    expect(page).to have_content('Solidus Mug')
+
+    expect(
+      find('link[rel=canonical]')[:href]
+    ).to eql('http://spreestore.example.com/products/?keywords=solidus')
+  end
+
+  it "renders a canonical tag for the products index with a taxon query string" do
+    create(:product_in_stock, name: 'Solidus Mug', taxons: [taxon])
+
+    visit products_path(keywords: 'solidus', taxon: taxon.id)
+
+    expect(page).to have_content('Solidus Mug')
+
+    expect(
+      find('link[rel=canonical]')[:href]
+    ).to eql("http://spreestore.example.com/products/?keywords=solidus&taxon=#{taxon.id}")
+  end
+
+  it "renders a canonical tag for taxon pages with a search filter query string" do
+    create(:product_in_stock, name: 'Solidus Mug', taxons: [taxon])
+
+    visit nested_taxons_path(taxon)
+
+    within "#sidebar_products_search" do
+      check "Under $10.00"
+      click_on "Search"
+    end
+    expect(page).to have_content "No products found"
+
+    expect(
+      URI::decode_uri_component find('link[rel=canonical]')[:href]
+    ).to eql(
+      "http://spreestore.example.com/t/solidus-brand/accessories?search[price_range_any][]=Under+$10.00"
+    )
+  end
+
+  it "renders a canonical tag for taxon pages with multiple pages of search results" do
+    create(:product_in_stock, name: 'Solidus Mug 1', taxons: [taxon])
+    create(:product_in_stock, name: 'Solidus Mug 2', taxons: [taxon])
+
+    visit nested_taxons_path(taxon, per_page: 1, page: 2)
+
+
+    expect(
+      find('link[rel=canonical]')[:href]
+    ).to eql("http://spreestore.example.com/t/solidus-brand/accessories?page=2")
+  end
 end