Add spec for CatalogItem serializer

engines/dfc_provider/app/serializers/dfc_provider/catalog_item_serializer.rb

@@ -28,7 +28,7 @@ module DfcProvider
     def references
       {
         '@type' => '@id',
-        '@id' => "/supplied_products/#{object.product_id}"
+        '@id' => reference_id
       }
     end
 
@@ -44,7 +44,7 @@ module DfcProvider
       dfc_provider_routes.api_dfc_provider_enterprise_supplied_product_url(
         enterprise_id: object.product.supplier_id,
         id: object.product_id,
-        host: root_url
+        host: host
       )
     end
   end

engines/dfc_provider/spec/serializers/dfc_provider/catalog_item_serializer_spec.rb

@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe DfcProvider::CatalogItemSerializer do
+  let!(:product) { create(:simple_product ) }
+  let!(:variant) { product.variants.first }
+
+  subject { described_class.new(variant) }
+
+  describe '#id' do
+    it 'returns the expected value' do
+      expect(subject.id).to eq(
+        DfcProvider::Engine.routes.url_helpers.api_dfc_provider_enterprise_catalog_item_url(
+          enterprise_id: product.supplier_id,
+          id: variant.id,
+          host: 'http://test.host'
+        )
+      )
+    end
+  end
+
+  describe '#references' do
+    it 'returns the expected value' do
+      expect(subject.references).to eq(
+        {
+          "@id" =>
+            DfcProvider::Engine.routes.url_helpers.api_dfc_provider_enterprise_supplied_product_url(
+              enterprise_id: product.supplier_id,
+              id: product.id,
+              host: 'http://test.host'
+            ),
+          "@type" => "@id"
+        }
+      )
+    end
+  end
+end