@brillout/jpp v0.1.3
JSON++
Same as JSON but with added support for:
Date
undefined
NaN
Inifinity
RegExp
JSON is great but is lacking for some (crucial) JavaScript types such as Date
:
const assert = require('assert');
let obj = {
time: new Date(),
};
assert(obj.time.constructor===Date);
// JSON converts dates to strings
obj = JSON.parse(JSON.stringify(obj));
assert(obj.time.constructor===String);
Whereas JSON++ supports Date
:
const assert = require('assert');
const parse = require('@brillout/jpp/parse');
const stringify = require('@brillout/jpp/stringify');
let obj = {
time: new Date(),
};
assert(obj.time.constructor===Date);
// JSON++ preserves Date
obj = parse(stringify(obj));
assert(obj.time.constructor===Date);
Usage
// npm install @brillout/jpp
const parse = require('@brillout/jpp/parse');
const stringify = require('@brillout/jpp/stringify');
const obj = {
hello: 'from the future',
time: new Date('2042-01-01'),
};
// Serialize with JSON++
const obj_serialized = stringify(obj);
// Deserialize a JSON++ string
const obj_deserialized = parse(obj_serialized);
JSON++'s stringify
and parse
have the exact same interface than JSON.stringify
and JSON.parse
.
So you can use all JSON's options.
Full example
Example exposing all differences between JSON and JSON++.
// /examples/jpp.js
const assert = require('assert');
const parse = require('@brillout/jpp/parse');
const stringify = require('@brillout/jpp/stringify');
const obj = {
date: new Date(),
undefined: undefined,
NaN: NaN,
Infinity: Infinity,
regexp: /^\d+$/g,
};
// All of `obj` can be serialized with JSON++
const obj_jpp = parse(stringify(obj))
assert(obj_jpp.date.getTime()===obj.date.getTime());
assert(obj_jpp.undefined===undefined && 'undefined' in obj_jpp);
assert(isNaN(obj_jpp.NaN));
assert(obj_jpp.Infinity===Infinity);
assert(obj_jpp.regexp.toString()===obj.regexp.toString());
// JSON cannot serialize any of `obj`
const obj_json = JSON.parse(JSON.stringify(obj))
// JSON converts dates to strings
assert(obj_json.constructor!==Date);
// JSON removes properties with a value of `undefined`
assert(!('undefined' in obj_json));
// JSON converts `NaN` to `null`
assert(obj_json.NaN===null);
// JSON converts `Infinity` to `null`
assert(obj_json.Infinity===null);
// JSON converts RegExp to an empty object
assert(obj_json.regexp.constructor===Object && Object.keys(obj_json.regexp).length===0);
To run the example:
$ git clone git@github.com:brillout/jpp.git
$ cd jpp
$ npm install
$ npm run link
$ node ./examples/jpp.js
The npm run link
is required to be able to self require('@brillout/jpp')
.
How it works
Let's see how JSON++ serializes an object:
// /examples/inspect.js
const stringify = require('@brillout/jpp/stringify');
const obj = {
date: new Date(),
undefined: undefined,
NaN: NaN,
Infinity: Infinity,
regexp: /^\d+$/g,
};
// We use the second argument `2` to have a prettified JSON++ string.
// (Same as in `JSON.stringify(obj, undefined, 2)`).
console.log(stringify(obj, undefined, 2));
// Prints:
/*
{
"date": "@brillout/jpp:tYpE|Date|2018-11-14T17:39:09.245Z",
"undefined": "@brillout/jpp:tYpE|undefined",
"NaN": "@brillout/jpp:tYpE|NaN",
"Infinity": "@brillout/jpp:tYpE|Infinity",
"regexp": "@brillout/jpp:tYpE|RegExp|/^\\d+$/g"
}
*/
JSON++ is based on JSON while using prefixed strings for unsupported types.
The string @brillout/jpp:tYpE
is used as a unique prefix to denote our special strings and make sure that regular strings are not converted.
@brillout/jpp
uses the native JSON.parse
and JSON.stringify
functions while modifying the serialization of unsupported types.