Add lookup of variants by semantic id

app/models/spree/variant.rb

@@ -170,6 +170,11 @@ module Spree
                                           select("spree_variants.id") })
     end
 
+    def self.linked_to(semantic_id)
+      includes(:semantic_links).references(:semantic_links)
+        .where(semantic_links: { semantic_id: }).first
+    end
+
     def tax_category
       super || TaxCategory.find_by(is_default: true)
     end

spec/models/spree/variant_spec.rb

@@ -488,6 +488,19 @@ RSpec.describe Spree::Variant do
     end
   end
 
+  describe ".linked_to" do
+    let!(:variant_unlinked) { create(:variant) }
+    let!(:variant_linked) { create(:variant, semantic_links: [link]) }
+    let!(:variant_linked_unrelated) { create(:variant, semantic_links: [unrelated_link]) }
+    let(:link) { SemanticLink.new(semantic_id: "#my_precious") }
+    let(:unrelated_link) { SemanticLink.new(semantic_id: "#other") }
+
+    it "finds a variant by link" do
+      expect(Spree::Variant.linked_to("#my_precious"))
+        .to eq variant_linked
+    end
+  end
+
   describe "generating the product and variant name" do
     let(:product) { variant.product }