jsonesc

Json Escape

Json Escape use escape character as prefix of string value to store types that normally not allowed in JSON

asc character 0x1b is used for the escaping

examples

// import JsonEsc from 'jsonesc';
const JsonEsc = require('jsonesc').default;

JsonEsc.stringify( [
  NaN,
  -Infinity,
  new Date(),
  new Uint8Array([1,2,3,4])
] );
// returns:
[
 "\u001bNaN",
 "\u001b-Inf",
 "\u001bDate:2018-02-07T19:07:18.207Z",
 "\u001bBin:6Fa-A"
]

Advantage

JsonEsc allows additional data types to be serialized in JSON, such as binary date (Uint8Array) and Date, while still keeps the verbose nature of JSON.
This makes JsonEsc much easier to debug and trouble shoot than binary formats like BSON and MsgPack

Performance

Modern browsers and nodejs are hightly optimized for JSON. This allows JsonEsc to be encoded and decoded faster than the other 2 formats in most of the cases.

benchmark result

Benchmark on Chrome 67 with sample data

Chrome 67, Firefox59, Edge 42
Time are all in ms, smaller is better

	Encode Chrome	Decode Chrome	Encode Firefox	Decode Firefox	Encode Edge	Decode Edge
JsonEsc	0.1161	0.1606	0.1394	0.1553	0.0899	0.0753
MsgPack	0.2465	0.1191	0.8663	0.2313	0.5752	0.2653
BSON	0.1255	0.1170	0.3634	0.6124	0.27005	0.37705

Custom Types

JsonEsc's register API make it really simple to add custom type into json encoding/decoding

// custom type
class MyClass {
  constructor(str) {
    this.myStr = str;
  }
}

let myJson = new JsonEsc();
myJson.register('My', MyClass,
  // custom encoder
  (obj) => obj.myStr,
  // custom decoder
  (str) => new MyClass(str)
);

myJson.stringify(new MyClass("hello"));
// "\u001bMy:hello"