<tr id="<%= spree_dom_id(variant) %>">
  <td class="image text-center">
    <% if variant.images.present? %>
      <%= image_tag variant.images.first.attachment.url(:mini) %>
    <% end %>
  </td>
  <td> <%= variant.sku_and_options_text %> </td>
  <td>
    <table class="table table-bordered no-marginb">
      <thead>
        <th> <%= Spree.t('sale_price_active') %></th>
        <th> <%= Spree.t('price') %> </th>
        <th> <%= Spree.t('sale_price') %> </th>
        <th> <%= Spree.t('sale_price_start_at') %> </th>
        <th> <%= Spree.t('sale_price_end_at') %> </th>
        <th> <%= Spree.t('sale_price_enabled') %> </th>
        <th class="actions text-center"></th>
      </thead>
      <tbody>
        <%= render partial: "sale_price", collection: variant.sale_prices, locals: { product: product, variant: variant } %>
      </tbody>
    </table>
  </td>
</tr>

<tr id="<%= spree_dom_id(variant) %>">
  <td class="image text-center">
    <% if variant.images.present? %>
      <%= image_tag variant.images.first.attachment.url(:mini) %>
    <% end %>
  </td>
  <td> <%= variant.sku_and_options_text %> </td>
  <td>
    <%- if variant.sale_prices.any? %>
      <table class="table table-bordered no-marginb">
        <thead>
          <th> <%= Spree.t('sale_price_active') %></th>
          <th> <%= Spree.t('price') %> </th>
          <th> <%= Spree.t('sale_price') %> </th>
          <th> <%= Spree.t('sale_price_start_at') %> </th>
          <th> <%= Spree.t('sale_price_end_at') %> </th>
          <th> <%= Spree.t('sale_price_enabled') %> </th>
          <th class="actions text-center"></th>
        </thead>
        <tbody>
          <%= render partial: "sale_price", collection: variant.sale_prices, locals: { product: product, variant: variant } %>
        </tbody>
      </table>
    <%- else %>
      <div class="no-objects-found alert alert-info">
        <%= Spree.t(:no_resource_found, resource: plural_resource_name(Spree::SalePrice)) %>
      </div>
    <% end %>
  </td>
</tr>

Add "No Sale Prices found" box when a variant has no sale prices
Add "No Sale Prices found" box when a variant has no sale prices
