Re add test for invalid cloned products

There is no easy way to make the original product invalid, but we can
make sure the cloned product will be invalid. The cloned product add
"COPe OF " in front of the product's name, so by starting with a name
that's long enough, the cloned product will have a name longer that 255
char and will then be invalid.

spec/lib/spree/core/product_duplicator_spec.rb

@@ -68,6 +68,21 @@
   end
 
   describe "errors" do
+    context "with invalid product" do
+      # Name has a max length of 255 char, when cloning a product the cloned product has a name
+      # starting with "COPY OF <product.name>". So we set a name with 254 char to make sure the
+      # cloned product will be invalid
+      let(:product) {
+        create(:product).tap{ |v| v.update_columns(name: "l" * 254) }
+      }
+
+      subject { Spree::Core::ProductDuplicator.new(product).duplicate }
+
+      it "raises RecordInvalid error" do
+        expect{ subject }.to raise_error(ActiveRecord::ActiveRecordError)
+      end
+    end
+
     context "invalid variant" do
       let(:variant) {
         # tax_category is required when products_require_tax_category

spec/models/spree/product_spec.rb

@@ -17,6 +17,13 @@ module Spree
           expect(clone.sku).to eq ""
           expect(clone.image).to eq product.image
         end
+
+        it 'fails to duplicate invalid product' do
+          # cloned product will be invalid
+          product.update_columns(name: "l" * 254)
+
+          expect{ product.duplicate }.to raise_error(ActiveRecord::ActiveRecordError)
+        end
       end
 
       context "product has variants" do

spec/system/admin/products_v3/actions_spec.rb

@@ -260,6 +260,21 @@ def expect_other_columns_visible
           end
         end
       end
+
+      it "shows error message when cloning invalid record" do
+        # The cloned product will be invalid
+        product_a.update_columns(name: "L" * 254)
+
+        # The page has not been reloaded so the product's name is still "Apples"
+        click_product_clone "Apples"
+
+        expect(page).to have_content "Unable to clone the product"
+
+        within "table.products" do
+          # Products does not include the cloned product.
+          expect(all_input_values).not_to match /COPY OF #{('L' * 254)}/
+        end
+      end
     end
 
     describe "delete" do