in-memory-website

A static website. In memory. You can save your website to a file, serve it, or upload it to S3.

What's a "static" website? "Static" means this:

• Only GET and HEAD requests are valid.
• The response for a given endpoint never changes.
• There are no errors. (A server may return 404 errors, and a server may receive erroneous HTTP requests; but those aren't website errors.)

Why "in memory"? Because it's crazy-fast for small websites. And it's better than storing the website as a bunch of files:

• A website doesn't have "folders": it has "paths". /foo can be an HTML file, and /foo/bar can also be an HTML file. See? /foo is not a folder.
• A website doesn't just return file contents: it also returns HTTP headers. Those headers aren't derived from the file contents.
• A website can have redirects.

How do you take advantage? Use a framework that outputs a "static website" in this format. This package provides the tools to develop and deploy within milliseconds.

Usage

First, npm install --save in-memory-website

Now, build your in-memory website. It can be as simple as this, my-website.js:

'use strict'
 
const StaticWebsite = require('in-memory-website').StaticWebsite
const website = new StaticWebsite([
  { path: '/hello-world', headers: { 'Content-Type': 'text/plain; charset=utf-8' }, body: Buffer.from('Hello, World!') }
])
 
// ... now let's see what we can do with this website.

Local website

Now you can serve the website locally. The 404 error page is a directory listing, and any response with a Location header becomes a 301 Moved Permanently.

// ... continuing above program
const DevServer = require('in-memory-website').HttpServer
const server = new HttpServer(website)
server.listen(3000) // and browse to http://localhost:3000

Saving a website as a file

You can dump the website to a file, and then reload it later:

// ... continuing above program
const fs = require('fs')
fs.writeFileSync('my-website.bin', website.toBuffer())
 
// ... and in a later program
const website2 = StaticWebsite.fromBuffer(fs.readFileSync('my-website.bin'))

Lightning-fast development server

Want to code a website? Good. Here's the pattern for you. It involves three scripts:

1. build.js: builds a website; outputs to stdout

#!/usr/bin/env node
'use strict'
 
const StaticWebsite = require('in-memory-server').StaticWebsite
const validate = require('in-memory-server').validate
 
// Normally our website generator would be more complex. Potentially it will
// be asynchronous. It may throw an error. Make this script exit with a
// non-zero error code if there's a problem.
const website = new StaticWebsite([
  {
    path: '/hello-world',
    headers: { 'Content-Type': 'text/plain; charset=utf-8' },
    body: Buffer.from('Hello, World!')
  }
])
 
// We have utilities to avoid common mistakes. Choose the mistakes you want
// to avoid; make this script exit with a non-zero error code if there's a
// problem.
const validationError = validate.headersAreUseful(website)
if (validationError) throw validationError
 
// No problem? Write the website to stdout and exit with a zero error code
// (the default).
process.stdout.write(website.toBuffer())

This is your framework: the program that builds your entire website. It outputs the website to process.stdout and exits with status code 0. If it fails (for instance, your framework has a syntax error), the error is output to process.stderr.

2. dev.js: serves a website; rebuilds automatically

#!/usr/bin/env node
'use strict'
 
const DevServer = require('in-memory-server').DevServer
 
const server = new DevServer(`${__dirname}/build.js`)
 
// In this dev environment, let's rebuild the website every time a file changes
const chokidar = require('chokidar') // https://github.com/paulmillr/chokidar
chokidar.watch([ 'src' ])
  .on('change', () => server.queueBuild())
  .on('add', () => server.queueBuild())
  .on('unlink', () => server.queueBuild())
  // queueBuild() is "debounced": if 10 files change very quickly, we only
  // rebuild once.
 
server.listen(3000, err => {
  if (err) throw err
  console.log('Listening at http://localhost:3000')
})
 
server.listenForLiveReload() // and use http://livereload.com/extensions/

This is your development environment: the program you run in the background while you work. It's a web server, at http://localhost:3000. It has some nifty features:

• Its "404 Not Found" page links to all the valid endpoints
• When build.js returns a status code that isn't 0, every endpoint is a 500 Internal Server Error with debugging information.
• It queues HTTP requests while rebuilding; those HTTP requests will complete when the build finishes.
• If you use a LiveReload browser extension the page will refresh whenever you change a file. That means you'll see the results of your code changes immediately -- be they error messages or bugfixes.

3. deploy.js: sends a website to a production server

#!/usr/bin/env node
'use strict'
 
const child_process = require('child_process')
const StaticWebsite = require('in-memory-website').StaticWebsite
const S3Uploader = require('in-memory-website').S3Uploader
 
// Throws error if build.js fails
const websiteData = child_process.execFileSync(`${__dirname}/build.js`)
const website = StaticWebsite.fromBuffer(websiteData)
 
S3Uploader.uploadWebsiteToBucket(website, 'my-bucket', {}, err => {
  if (err) throw err
})

Lightning-fast production server

Hosting on S3 is cheap and fast. TODO add tutorial.

Backup production server

We supply Express middleware to help you build your own web server. For instance:

#!/usr/bin/env node
'use strict'
 
const express = require('express')
const StaticWebsite = require('in-memory-website').StaticWebsite
const ExpressApp = require('in-memory-website').ExpressApp
 
const websiteData = require('fs').readFileSync('websiteDumpedSomewhere.data')
const website = StaticWebsite.fromBuffer(websiteData)
 
const app = express()
app.use(ExpressApp(website))
 
app.listen(3000, () => { console.log('Listening at http://localhost:3000') })

License

Copyright (c) 2017 The Huffington Post, released under the MIT license. See LICENSE.