Hide the discount code on the Easy Digital Downloads checkout and show the discount name instead

edd-hide-discount-code.php

<?php
/**
 * Show EDD discount name instead of code in checkout summary.
 */
function my_custom_edd_discount_display( $discount_html, $discount ) {

	$discount = edd_get_discount_by_code( $discount );

	if ( ! $discount ) {
		return $discount_html;
	}

	$discount_html = str_replace( $discount . '&nbsp;', $discount->name . '&nbsp;', $discount_html );

	return $discount_html;
}

add_filter( 'edd_get_cart_discount_html', 'my_custom_edd_discount_display', 10, 2 );