A JSON parser that isn't strict.


A JSON parser that can parse "bad" JSON. Mostly, this is about avoiding the need to quote everything!

Strict JSON requires you to do this:

{ "foo":"bar", "red":1 }

The JavaScript language itself is a little easier:

{ foo:"bar", red:1, }

But if you really want to be lazy, jsonic lets you say:

foo:bar, red:1,

See below for the relaxed JSON rules.

This module is used by the Seneca framework to provide an abbreviated command syntax.

If you're using this module, feel free to contact me on twitter if you have any questions! :) @rjrodger

Current Version: 0.2.2

Tested on: node 0.10, 0.11, 0.12, iojs, Chrome 43, Safari 7, Firefox 38

var jsonic = require('jsonic')
// parse a string into a JavaScript object
var obj = jsonic('foo:1, bar:zed')
// prints { foo: '1', bar: 'zed' }
console.dir( obj )
npm install jsonic

Relaxed Rules

JSONIC format is just standard JSON, with a few rule relaxations:

  • You don't need to quote property names: { foo:"bar baz", red:255 }
  • You don't need the top level braces: foo:"bar baz", red:255
  • You don't need to quote strings with spaces: foo:bar baz, red:255
  • You do need to quote strings if they contain a comma or closing brace or square bracket: icky:"_,}]_"
  • You can use single quotes for strings: Jules:'Cry "Havoc," and let slip the dogs of war!'
  • You can have trailing commas: foo:bar, red:255,


The jsonic module provides a stringify method:

console.log( jsonic.stringify( {a:"bc",d:1} ) ) // prints {a:bc,d:1}  

The stringify method converts a plain JavaScript object into a string that can be parsed by jsonic. It has two parameters:

  • value: plain object
  • options: optional options object

For example, you can limit the depth of the object tree printed:

console.log( jsonic.stringify( {a:{b:{c:1}}}, {depth:2} ) ) // prints {a:{b:{}}}  

NOTE: jsonic.stringify is intended for debug printing, not data exchange, so the defaults are conservative in the amount of data printed

The options are:

  • depth: default: 3; maximum depth of sub-objects printed; NOTE: there is no infinite-cycle protection, just this finite depth
  • maxitems: default: 11; maximum number of array elements or object key/value pairs printed
  • maxchars: default: 111; maximum number of characters printed
  • omit: default:__[]__; omit listed keys from objects
  • exclude: default:__['$']__; omit keys from objects if they contain any of the listed values

The parser uses PEG.js and is an extension of the example JSON parser included in that project.