Test Subscription

stripe.php

if ( 'invoice.payment_succeeded' == $event->type ) {
    $user_id      = $wpdb->get_var( "SELECT `user_id` FROM $wpdb->usermeta WHERE `meta_key` = '_stripe_subscription_id' AND `meta_value`='$invoice->subscription'" );
    $period_start = date( 'Y-m-d H:i:s', $invoice->period_start );
    $period_end   = date( 'Y-m-d H:i:s', $invoice->period_end );
    $order_id     = get_user_meta( $user_id, 'product_order_id', true );

    if ( $invoice->paid ) {
        update_user_meta( $user_id, 'product_pack_startdate', $period_start );
        update_user_meta( $user_id, 'product_pack_enddate', $period_end );
        update_user_meta( $user_id, 'can_post_product', '1' );
        update_user_meta( $user_id, 'has_pending_subscription', false );

        if ( !empty( $invoice->charge ) ) {
            update_post_meta( $order_id, '_stripe_subscription_charge_id', $invoice->charge );
        }
    }
}