index.js

'use strict';

var Future = require('data.future');
var url = require('url');
var _ = require('lodash');

module.exports = exports = function makeRouter(route, handler, parent) {
  var router = function routeHandler(oreq, ores, onext) {
    if (onext == null) {
      onext = function next(req, res) {
        return Future.of(res);
      };
    }

    if (parent == null) {
      if (oreq.path == null || oreq.query == null) {
        var data = url.parse(oreq.url, true);

        oreq.path = data.pathname;
        oreq.query = data.query;
      }

      return onext(oreq, ores);
    }

    return parent(oreq, ores, function next(req, res) {
      var path = req.path;

      // skip if route doesn't match
      if (path.toLowerCase().substr(0, route.length) !== route.toLowerCase()) {
        return onext(req, res);
      }

      // skip if route match does not border '/', '.' or end
      var c = path[route.length];
      if (c !== undefined && c !== '/' && c !== '.') {
        return onext(req, res);
      }

      var removed;

      // trim off the part of the url that matches the route
      if (route.length !== 0 && route !== '/') {
        removed = route;

        var fqreq = _.clone(req);
        fqreq.url = sliceAtRemoved(req.url);
        fqreq.path = sliceAtRemoved(req.path);

        return handler(fqreq, res, function next(nreq, nres) {
          var fqreq = _.clone(nreq);
          fqreq.url = insertRemoved(nreq.url);
          fqreq.path = insertRemoved(nreq.path);

          return onext(nreq, nres);
        });
      }

      return handler(req, res, onext);

      function sliceAtRemoved(path) {
        path = path.slice(removed.length);

        if (path[0] === '/') {
          return path;
        } else {
          return '/' + path;
        }
      }

      function insertRemoved(path) {
        if (removed[removed.length] === '/') {
          return removed + path.slice(1);
        } else {
          return removed + path;
        }
      }
    });
  };

  router.use = function(route, fn) {
    if (typeof route !== 'string') {
      fn = route;
      route = '/';
    }

    if (route[route.length - 1] === '/') {
      route = route.slice(0, -1);
    }

    return makeRouter(route, fn, router);
  };

  router.useAll = function(routes) {
    return reduce(function(router, route) {
      if (typeof route === 'function') {
        return router.use(route);
      } else {
        return router.use(route[0], route[1]);
      }
    }, router, routes);
  };

  return router;
};

function reduce(fn, data, array) {
  var index = -1;
  var length = array.length;

  while (index++ < length) {
    data = fn(data, array[index]);
  }

  return data;
}