Minimal NodeJS HTTP router, made for an example. Kudos to @asotirov

router.js

/* global module, console */

module.exports = function(http, port) {
  'use strict';
  var routes = {};
  var exportMethods = {};
  var middlewares = [];

  ['get', 'post', 'put', 'delete'].forEach(function(method) {
    routes[method] = routes[method] || {};
    exportMethods[method] = (function(method) {
      return function(url, callback) {
        return route(method, url, callback);
      };
    }(method));
  });

  var server = http.createServer(function(req, res) {
    var requestedUrl = req.url;
    var requestedMethod = req.method.toLowerCase();
    var routeHandler = routes[requestedMethod];

    if(!routeHandler) {
      throw new Error('Cannot handle method: ' + requestedMethod);
    }

    var handled = false;
    Object.keys(routeHandler).forEach(function(url) {
        if(requestedUrl === url) {
          handled = true;
          routeHandler[url].forEach(function(callback) {
              invoke(req, res, callback);
          });
        }
      });
    if(!handled) {
      res.writeHead(404);
      res.end("Not found");
    }
  });


  function invoke(req, res, callback) {
    invokeMiddlewares(req, res, middlewares, callback);
  }

  function invokeMiddlewares(req, res, middlewares, callback) {
    var index = 0;
    function next() {
      if(index === middlewares.length) {
        callback(req, res);
      } else {
        console.log('Executing middleware ' + index);
        middlewares[index++](req, res, next);
      }
    }
    next();
  }

  function use (middleware) {
    middlewares.push(middleware);
  }

  function route(method, url, callback) {
    var routesForMethod = routes[method];
    if(!routesForMethod) {
      throw new Error('Cannot handle method: ' + method);
    }
    routesForMethod[url] = routesForMethod[url] || [];
    routesForMethod[url].push(callback);
  }

  exportMethods.listen = server.listen.bind(server);
  exportMethods.use = use;
  return exportMethods;
};

test-router.js

var http= require("http"),
      router = require("./router")(http);

router.use(function(req, res, next) {
  var data = '';

  req.on('data', function(chunk){
    data+=chunk.toString();
  });

  req.on('end', function() {
    req.data = data;

    try {
      var body = JSON.parse(data);
      req.body=body;
      next();
    } catch(e) {
      next('Invalid JSON body.');
    }
  });
});

router.get('/panda', function(req, res) {
  res.end('Pandaaaaaa!');
});

router.post("/panda", function(req, res) {
  console.log(req.data, req.body);
  res.end("PANDALISM");
});

router.listen(8081);