json-s v0.1.0
JSON-S
JSON-Serializer
Same as JSON but with added support for:
Date
undefined
NaN
Inifinity
RegExp
JSON is a great serializer.
But it is lacking for some JavaScript types such as Date
:
const assert = require('assert');
let obj = {
time: new Date('2042-01-01'),
};
// JSON converts dates to strings
assert(obj.time.constructor===Date);
obj = JSON.parse(JSON.stringify(obj));
assert(obj.time.constructor===String);
assert(obj.time==='2042-01-01T00:00:00.000Z');
Whereas with JSON-S:
const assert = require('assert');
const JSON = require('json-s');
let obj = {
time: new Date('2042-01-01'),
};
// JSON-S preserves Date
assert(obj.time.constructor===Date);
obj = JSON.parse(JSON.stringify(obj));
assert(obj.time.constructor===Date);
assert(obj.time.getTime()===new Date('2042-01-01').getTime());
Contents
Usage
// npm install json-s
const parse = require('json-s/parse');
const stringify = require('json-s/stringify');
const obj = {
hello: 'from the future',
time: new Date('2042-01-01'),
};
// Serialize with JSON-S
const obj_serialized = stringify(obj);
// Deserialize a JSON-S string
const obj_deserialized = parse(obj_serialized);
The JSON-S functions 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-S.
// /examples/json-s.js
const assert = require('assert');
const parse = require('json-s/parse');
const stringify = require('json-s/stringify');
const obj = {
date: new Date(),
undefined: undefined,
NaN: NaN,
Infinity: Infinity,
regexp: /^\d+$/g,
};
// All of `obj` can be serialized with JSON-S
const obj2 = parse(stringify(obj))
assert(obj2.date.getTime()===obj.date.getTime());
assert(obj2.undefined===undefined && 'undefined' in obj2);
assert(isNaN(obj2.NaN));
assert(obj2.Infinity===Infinity);
assert(obj2.regexp.toString()===obj.regexp.toString());
// JSON cannot serialize any of `obj`
const obj3 = JSON.parse(JSON.stringify(obj))
// JSON converts dates to strings
assert(obj3.constructor!==Date);
// JSON removes properties with a value of `undefined`
assert(!('undefined' in obj3));
// JSON converts `NaN` to `null`
assert(obj3.NaN===null);
// JSON converts `Infinity` to `null`
assert(obj3.Infinity===null);
// JSON converts RegExp to an empty object
assert(obj3.regexp.constructor===Object && Object.keys(obj3.regexp).length===0);
To run the example:
$ git clone git@github.com:brillout/json-s
$ cd json-s
$ npm install
$ npm run link
$ node ./examples/json-s.js
The npm run link
is required to be able to self require('json-s')
.
How it Works
Let's see how JSON-S serializes an object:
// /examples/inspect.js
const JSON = require('json-s');
const obj = {
date: new Date(),
undefined: undefined,
NaN: NaN,
Infinity: Infinity,
regexp: /^\d+$/g,
};
// We use the second argument `2` to have a prettified JSON-S string.
// (Same as in JSON's `JSON.stringify(obj, undefined, 2)`).
console.log(JSON.stringify(obj, undefined, 2));
// Prints:
/*
{
"date": "json-s:tYpE|Date|2018-11-14T17:39:09.245Z",
"undefined": "json-s:tYpE|undefined",
"NaN": "json-s:tYpE|NaN",
"Infinity": "json-s:tYpE|Infinity",
"regexp": "json-s:tYpE|RegExp|/^\\d+$/g"
}
*/
JSON-S is based on JSON while using prefixed strings for unsupported types.
The string json-s:tYpE
is used as a unique prefix to denote our special strings and make sure that regular strings are not converted.
json-s
uses the native JSON.parse
and JSON.stringify
functions while modifying the serialization of unsupported types.
5 years ago
5 years ago