Mostrar valor do desconto em vez de Oferta nas promoções dos produtos cadastrados no Woocommerce

Basta adicionar o seguinte código no arquivo functions.php do seu tema:

/** mostrar desconto em vez do texto oferta**/
add_filter( 'woocommerce_sale_flash', 'add_percentage_to_sale_badge', 20, 3 );
function add_percentage_to_sale_badge( $html, $post, $product ) {
if( $product->is_type('variable')){
$percentages = array();

// Get all variation prices
$prices = $product->get_variation_prices();

// Loop through variation prices
foreach( $prices['price'] as $key => $price ){
// Only on sale variations
if( $prices['regular_price'][$key] !== $price ){
// Calculate and set in the array the percentage for each variation on sale
$percentages[] = round(100 - ($prices['sale_price'][$key] / $prices['regular_price'][$key] * 100));
}
}
$percentage = max($percentages) . '%';
} else {
$regular_price = (float) $product->get_regular_price();
$sale_price= (float) $product->get_sale_price();

$percentage= round(100 - ($sale_price / $regular_price * 100)) . '%';
}
return '<span class="onsale">' . esc_html__( '-', 'woocommerce' ) . ' ' . $percentage . '</span>';
}