Show inline errors for product fields

The form helper () doesn't work for this case, but it seems we can call it directly like this instead. I'd like to fix the helper, but got stuck this time.

app/views/admin/products_v3/_table.html.haml

@@ -41,8 +41,10 @@
             %td.align-left.header
               = product_form.hidden_field :id
               = product_form.text_field :name, 'aria-label': t('admin.products_page.columns.name')
+              = error_message_on product, :name
             %td.align-right
               = product_form.text_field :sku, 'aria-label': t('admin.products_page.columns.sku')
+              = error_message_on product, :sku
             %td.align-right
               .content
                 = product.variant_unit.upcase_first

spec/system/admin/products_v3/products_spec.rb

@@ -201,7 +201,7 @@ describe 'As an admin, I can see the new product page' do
       visit admin_products_v3_index_url
     end
 
-    it "can update product and variant fields" do
+    it "updates product and variant fields" do
       within row_containing_name("Apples") do
         fill_in "Name", with: "Pommes"
         fill_in "SKU", with: "POM-00"
@@ -236,7 +236,7 @@ describe 'As an admin, I can see the new product page' do
       expect(page).to have_content "Changes saved"
     end
 
-    it "can discard changes and reload latest data" do
+    it "discards changes and reloads latest data" do
       within row_containing_name("Apples") do
         fill_in "Name", with: "Pommes"
       end
@@ -262,6 +262,28 @@ describe 'As an admin, I can see the new product page' do
         expect(page).to have_field "SKU", with: "APL-10" # Updated value shown
       end
     end
+
+    it "shows errors for product fields" do
+      within row_containing_name("Apples") do
+        fill_in "Name", with: ""
+        fill_in "SKU", with: "A" * 256
+      end
+
+      expect {
+        click_button "Save changes"
+        product_a.reload
+      }.to_not change { product_a.name }
+
+      # (there's no identifier displayed, so the user must remember which product it is..)
+      within row_containing_name("") do
+        expect(page).to have_field "Name", with: ""
+        expect(page).to have_content "can't be blank"
+        expect(page).to have_field "SKU", with: "A" * 256
+        expect(page).to have_content "is too long"
+      end
+      pending
+      expect(page).to have_content "Please review the errors and try again"
+    end
   end
 
   def expect_page_to_be(page_number)