path-router.js

export const createRouter = defaultCallback => ({
    _exactRoutes: {},
    _subRouters: {},
    _defaultRoute: defaultCallback
});

export const setExactRoute = (router, pathname, callback) => {
    router._exactRoutes[pathname] = callback;
};

export const setSubRouter = (router, subPath, subRouter) => {
    router._subRouters[subPath] = subRouter;
};

export const findRoute = (router, pathname) => {
    if (pathname in router._exactRoutes) {
        return fullPath => router._exactRoutes[pathname]('', fullPath);
    }

    const subrouterMatches = Object.keys(router._subRouters)
        .filter(p => pathname.startsWith(p))
        .sort((a, b) => b.length - a.length);
    for (const subrouterPath of subrouterMatches) {
        const subrouter = router._subRouters[subrouterPath];
        const tailPath = pathname.replace(subrouterPath, '');
        const callback = findRoute(subrouter, tailPath);
        if (callback) {
            return callback;
        }
    }

    if (router._defaultRoute) {
        return fullPath => router._defaultRoute(pathname, fullPath);
    }
};

export const executeRoute = (router, pathname) => findRoute(router, pathname)(pathname);