WooCommerce Additional Information - if empty, hide

add_filter( 'woocommerce_product_tabs', 'am_ninja_remove_product_tabs', 98 );

function am_ninja_remove_product_tabs( $tabs ) {

    global $product;
    $id = $product->get_id(); // change this to $product->id fro WC less than 2.7

    $my_custom_data = get_post_meta($id, 'am_ninja', true );  

    if(empty($my_custom_data)) {
        unset( $tabs['additional_information'] );   // Remove the additional information tab
    }

    return $tabs;
}

//Removing product data tabs
add_action('init', 'tws_remove_product_tabs');

function tws_remove_product_tabs() {
  remove_action('woocommerce_after_single_product_summary', 'woocommerce_output_product_data_tabs', 10);
}

//Adding product additional info in summary - if it's empty hide it
add_action('woocommerce_single_product_summary', 'woocommerce_product_additional_information_tab', 25);

function woocommerce_product_additional_information_tab() {
  global $product;
  if ($product - > has_attributes() || $product - > has_dimensions() || $product - > has_weight()) { // Check if product has attributes, dimensions or weight 
    return $tabs;
    wc_get_template('single-product/tabs/additional-information.php');
  }
}

   [1]: https://docs.woocommerce.com