npm install buffer-json

const BJSON = require('buffer-json')

const str = BJSON.stringify({ buf: Buffer.from('hello') })
// => '{"buf":{"type":"Buffer","data":"base64:aGVsbG8="}}'

BJSON.parse(str)
// => { buf: <Buffer 68 65 6c 6c 6f> }

The Buffer class in Node.js is used to represent binary data. JSON does not specify a way to encode binary data, so the Node.js implementation of JSON.stringify represents buffers as an object of shape { type: "Buffer", data: [<bytes as numbers>] }. Unfortunately, JSON.parse does not turn this structure back into a Buffer object:

$ node
> JSON.parse(JSON.stringify({ buf: Buffer.from('hello world') }))
{ buf:
   { type: 'Buffer',
     data: [ 104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100 ] } }

JSON.stringify and JSON.parse accept arguments called replacer and reviver respectively which allow customizing the parsing/encoding behavior. This module provides a replacer which encodes Buffer data as a base64-encoded string, and a reviver which turns JSON objects which contain buffer-like data (either as arrays of numbers or strings) into Buffer instances. All other types of values are parsed/encoded as normal.

Convenience wrapper for JSON.stringify with the replacer described below.

Convenience wrapper for JSON.parse with the reviver described below.

A replacer implementation which turns every value that is a Buffer instance into an object of shape { type: 'Buffer', data: 'base64:<base64-encoded buffer content>' }. Empty buffers are encoded as { type: 'Buffer', data: '' }.

A reviver implementation which turns every object of shape { type: 'Buffer', data: <array of numbers or string> } into a Buffer instance.

• buffer-json-encoding: an abstract-encoding compatible JSON encoder/decoder which uses this module.

MIT