bahmutov / connect-slow

Middleware to delay answering requests based on request url, useful to diagnose website behavior based on load delays

connect-slow v0.0.0

Middleware to delay answering requests based on request url, useful to diagnose website behavior based on load delays

[![semantic-release][semantic-image] ][semantic-url]

var connect = require('connect');
var http = require('http');
var slow = require('connect-slow');
var app = connect()
    .use(connect.logger('dev'))
    .use(slow({
        url: /\.jpg$/i,
        delay: 2000
    }))
    .use(connect.static('public'));
http.createServer(app).listen(4000);
$ curl http://localhost:4000/index.html  // 1 ms
$ curl http://localhost:4000/foto.jpg    // 2001 ms

Works with Connect, Express, turtle-run. If you use Koa see koa-slow.

Why?

Controlled server-side delays allow to debug and polish website behavior, see Give browser a chance

install:

npm install connect-slow --save

slow down every requst by 1 second (default delay value)

var slow = require('connect-slow');
var app = connect()
    .use(slow())
    ...

slow down JPEG images by 500ms, let everything else be served as quick as possible

var slow = require('connect-slow');
var app = connect()
    .use(slow({
        url: /\.[jpg|jpeg]$/i,
        delay: 500
    }))
    ...

slow down JPEG images by 1000ms, slow down JavaScript files by 100ms

var slow = require('connect-slow');
var app = connect()
    .use(slow({
        url: /\.[jpg|jpeg]$/i,
        delay: 1000
    }))
    .use(slow({
        url: /\.js$/i,
        delay: 100
    }))
    ...

You can see console log of delayed urls by passing option debug

slow({
    url: /\.[jpg|jpeg]$/i,
    delay: 1000,
    debug: true
})

Related projects

• connect-pause - extremely simple delay
• koa-slow - same funtionality as connect-slow for Koa server

Small print

Author: Gleb Bahmutov © 2014

• @bahmutov
• glebbahmutov.com
• blog

License: MIT - do anything with the code, but don't blame me if it does not work.

Spread the word: tweet, star on github, etc.

Support: if you find any problems with this module, email / tweet / open issue on Github

MIT License

Copyright (c) 2014 Gleb Bahmutov

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

connect-slow's Issues

Fix unit tests

Broken due to connect logger and Q

Request-based delays

It would be useful if individual requests could specify a delay period, for example /comment/100?delay=1000. /comment/100/delay/1000 is also nice but would clearly need some URL rewriting.

This form would be useful when client and server apps are in different codebases or it is impractical to frequently modify and restart the server when testing delays on different endpoints.

What do you think? I am happy to submit a PR if you like the idea.