/**
* Test setting custom fields.
* @since 2.7.0
*/
public function test_set_custom_fields()
{
$coupon = WC_Helper_Coupon::create_coupon();
$coupon_id = $coupon->get_id();
$meta_value = time() . '-custom-value';
$coupon->add_meta_data('my-custom-field', $meta_value, true);
$coupon->save();
$coupon = new WC_Coupon($coupon_id);
$this->assertEquals($meta_value, $coupon->get_meta('my-custom-field'));
}