Superagent cache middleware

app.js

/**
 * Module dependencies
 */
var request = require("superagent")
  , cache = require("./cache");
 
// Add the cache to the default middleware
request.middleware.push(cache());
 
request
  .get("/api")
  .end(function(err, res){
    // Should hit the server
    console.log(res.body);
    
    request
      .get("/api")
      .end(function(err, res){
        // Should not hit the server but still return the same response
        console.log(res.body);
      });
  });

cache.js

/**
 * Module dependencies
 */
 
/**
 * Cache
 */
var cache = {};
 
/**
 * Cache middleware
 * 
 * @return {Function}
 * @api public
 */
module.exports = function() {
  return function(req, next) {
    if(cache[req.url]) {
      req.emit("response", cache[req.url]);
      return req.emit("end");
    }
    
    next(null, function(res, prev){
      if(res.ok) {
        cache[req.url] = res;
      }
      prev();
    });
  }
}