How to check if a coupon has granted free shipping in Woocommerce? - woocommerce

Question

ORIGINAL QUESTION:
We need to know if a coupon has specifically granted free shipping.
In my test scenario I have two coupons applied to the cart, one with free shipping and one without. The var_dump clearly shows one coupon like this:
["free_shipping"]=>
bool(true)
However, when using
echo "<p>Free shipping: ".(int)$coupon->free_shipping."</p>";
It always displays 0.
I can't figure out what I am doing wrong.
Here's the code:
add_action('woocommerce_before_cart_totals', 'check_free_shipping_on_coupon');
function check_free_shipping_on_coupon() {
global $woocommerce;
if ( ! empty( $woocommerce->cart->applied_coupons ) ) {
$my_coupon = $woocommerce->cart->get_coupons() ;
foreach($my_coupon as $coupon){
if ( $post = get_post( $coupon->id ) ) {
echo "<p>ID: ".$coupon->id . "</p>";
echo "<p>Code: ".$coupon->code."</p>";
echo "<p>Amount: ".$coupon->amount."</p>";
if ( !empty( $post->post_excerpt ) ) {
echo "<p>Excerpt: ".$post->post_excerpt."</p>";
}
echo "<p>Free shipping: ".(int)$coupon->free_shipping."</p>";
if ( (int)$coupon->free_shipping == '1'){//I want to do stuff here;
}
//Dump everything for reference
echo '<pre>' , var_dump($coupon) , '</pre>';
}
}
}
}
UPDATE:
I found another question here: Set all shipping methods cost to zero for a Free shipping coupon in Woocommerce that had a code snippet that solved my question, but in a very different way. I am still curious why my original code did not work.
Working code:
//Check if a coupon has granted free shipping
add_action('woocommerce_before_cart_totals', 'rnr_check_free_shipping_on_coupon');
function rnr_check_free_shipping_on_coupon() {
$applied_coupons = WC()->cart->get_applied_coupons();
foreach( $applied_coupons as $coupon_code ){
$coupon = new WC_Coupon($coupon_code);
if($coupon->get_free_shipping()){
echo 'You have a free shipping coupon!';
}
}
}