• support node and headless chrome
• support requiring npm modules from node_modules
• support session as well as one shoot evaluation
• babel support
• wait for promises to resolve
• no need to return
• avoid using let or const

• session
• file
• babel

#+BEGIN_SRC javascript
new Date
#+END_SRC

#+RESULTS:
: 2016-11-26T05:23:47.867Z

if the code block yields a promise, it will be inspected after resolution, the default timeout is 5 seconds

#+BEGIN_SRC javascript
fetch = require('node-fetch')

fetch('https://api.github.com/repos/zweifisch/ob-coffee/languages')
  .then(res => res.json())
#+END_SRC

#+RESULTS:
: { 'Emacs Lisp': 4069, JavaScript: 184 }

requires `babel-cli`

#+BEGIN_SRC javascript :babel
import fetch from 'node-fetch'

(async () => {
  let res = await fetch('https://api.github.com/repos/zweifisch/ob-javascript/languages')
  return res.json()
})()
#+END_SRC

#+RESULTS:
: { 'Emacs Lisp': 3993, JavaScript: 864 }

if the code block yields buffer or stream, and :file is specified, the result will be written to disk

#+BEGIN_SRC javascript :file canvas.png
Canvas = require('canvas')
canvas = new Canvas(100, 100)
ctx = canvas.getContext('2d')

ctx.arc(50, 50, 50, -Math.PI * 0.5, Math.PI, false)
ctx.fillStyle = '#0ff'
ctx.fill()

canvas.toBuffer()
#+END_SRC

#+RESULTS:

#+BEGIN_SRC javascript :session http://gnu.org
document.querySelector('title').text
#+END_SRC

#+RESULTS:
: The GNU Operating System and the Free Software Movement