reverse_route.js

function reverse_route(ctx) {
    var paths = [];
    var router = ctx;
    var params = ctx.params || {};
    paths.unshift(router.route.path);

    while (!router.isRoot && router.$parent) {
        router = router.$parent;
        Object.assign(params, router.params);
        if (router) paths.unshift(router.route.path);
    }

    var path = paths.reduce((ps, p) => ps + p.replace('/:__child_path__(.*)?', ''), '')
        .replace(new RegExp('\/\/', 'g'), '/');
    return { path, params };
}