Assigning value in Scss and run if then else on it

I am trying to conditionally add '|' to a menu if it has been toggled or not.

$my_boolean = aria-expanded;
@if $my_boolean == true {
    .nav-secondary .genesis-nav-menu > .menu-item > a::after {
        content: "";
        padding-left: 8px;
    }
} @else {
    .nav-secondary .genesis-nav-menu > .menu-item > a::after {
        content: "|";
        padding-left: 8px;
    }
}