json-stringify-extended

JSON.stringify any data types

Purpose

• stringify primitive js types properly without limitation
• manipulate objects while serializing
• get control on circular reference
• use custom types not yet defined (e.g. enums)
• avoid quotes if not needed

Installing

npm i json-stringify-extended

Quick start

const stringify = require('json-stringify-extended')

const data = {
  a: 'basic set, default options',
  b: 1,
  c: true,
  d: function (a, b) { console.log(a + b) },
  e: {a: 0, b: 0.1, c: -2},
  f: ['a', 'b', 'c'],
  g: new Date('2017-01-01'),
  h: /a|b/,
  i: null,
  j: Infinity,
  k: NaN,
  l: undefined,
  m: stringify.deferred('my.enum.VALUE'),
  n: Buffer.from('7468697320697320612074c3a97374', 'hex'),
  o: Symbol('cross'),
  p: new Map([[1, 'Rico'], [2, 'Mimi']]),
  q: new Set(['cuori', 'quadri', 'picche', 'fiori'])
}

console.log(stringify(data))

// output
{
  a:"basic set, default options",
  b:1,
  c:true,
  d:function (a, b) { console.log(a + b) },
  e:{
    a:0,
    b:0.1,
    c:-2
  },
  f:[
    "a",
    "b",
    "c"
  ],
  g:new Date("2017-01-01T00:00:00.000Z"),
  h:/a|b/,
  i:null,
  j:Infinity,
  k:NaN,
  l:undefined,
  m:my.enum.VALUE,
  n:Buffer.from("dGhpcyBpcyBhIHTDqXN0"),
  o:Symbol("cross"),
  p:new Map([
    [
      1,
      "Rico"
    ],
    [
      2,
      "Mimi"
    ]
  ]),
  q:new Set([
    "cuori",
    "quadri",
    "picche",
    "fiori"
  ])
}

Supported types

• string
• number
• boolean
• function
• Object
• Array
• Date
• RegExp
• Buffer
• Symbol
• Map
• Set
• null
• Infinity
• NaN
• undefined
• Not-yet defined using stringify.deferred

API docs

stringify (data[, options])

stringify data into string

data

Type: any

options

Type: Object

Parameters to configure result format.

You can also use this prepared options:

• stringify.options.json format to regular JSON format
• stringify.options.standadjs format using standadjs rules
• stringify.options.compact format without folding, quotes and spaces

example

const data = {a: 'string', b: false, c: [0, 1, 2]}
console.log (stringify (data, stringify.options.compact))
// output
{a:'string',b:false,c:[0,1,2]}

options.filter

Type: function(key:string, value:string) return boolean
Default: null

Use the function to filter key and/or value of each element.
Return true to save element or false to discard.
filter applies before replace.

example

const data = {
 user: 'alice',
 password: 'it-s-a-secret',
 id: 1,
 meta: ['1', 1],
 greet: function() { return 'hi' }
}
const options = {
 filter: function (key, value) {
   if (key === 'password') {
     return false
   }
   if (value === 1) {
     return false
   }
   if (typeof value === 'function') {
     return false
   }
   return true
 }
}
console.log(stringify(data, options))
// output
{
 user:"alice",
 meta:[
   "1"
 ]
}

options.replace

Type: function(key:string, value:string) return {key, value}
Default: null

Use the function to replace key and/or value of each element.
Have to return an object {key, value}.
filter applies before replace.

example

const data = {
 user: 'alice',
 password: 'it-s-a-secret',
 id: 1,
 meta: ['1', 1]
}
const options = {
 replace: function (key, value) {
   if (key === 'password') {
     return {key: 'secret', value: '***'}
   }
   if (value === 1) {
     return {key, value: 'one'}
   }
   return {key, value}
 }
}
console.log(stringify(data, options))
// output
{
 user:"alice",
 secret:"***",
 id:"one",
 meta:[
   "1",
   "one"
 ]
}

options.safe

Type: boolean
Default: false

Works in safe mode, so it will not throws exception for circularity.

options.endline

Type: string
Default: \n

Endline string should contain spacing chars as \n or \r\n. Set to empty string '' for one line output.

options.spacing

Type: string
Default: (two spaces)

Indentation string should contains only spacing chars as \t or spaces .

options.compress

Type: boolean
Default: false

Compress data for function and Date. Note: in version < 2.0.0 also discard null and undefined values.

options.keyQuote

Type: string
Default: null

The character to be used for quote is the “ key, the default is null, meaning no quotes in keys. And " or ' or null means there is a quote.

options.valueQuote

Type: string
Default: '

The character to be used for quote values default is '. Must be " or '.

options.keySpace

Type: boolean
Default: false

Add a space between key: and value.

options.discard

Type: boolean
Default: false

Discard values null and undefined.

Changelog

v. 2.2.0

• support Map and Set types

v. 2.1.0

• support Symbol type
• 100% code coverage
• drop node < 10

v. 2.0.0

• separate compress and discard option (to keep object keys on compress)

License

The MIT License (MIT)

Copyright (c) 2017-2020 Simone Sanfratello

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.