@lachenmayer/buffer-json v1.0.1

buffer-json

npm install @lachenmayer/buffer-json

const BJSON = require('@lachenmayer/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.

API

stringify(value[, space])

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

parse(text)

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

replacer(key, value)

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: '' }.

reviver(key, value)

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

History

This is a fork of https://github.com/jprichardson/buffer-json/ - I initially forked the module because it crashed when used with objects where some values are null or undefined. Looking deeper into it I noticed that it was using the deprecated Buffer constructor and other deprecated methods from mocha. I decided to fix the bugs, simplify the logic, and bring it up to date with current APIs (ie. using Buffer.from(...) instead of new Buffer and using tape for tests).

Related modules

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

License

MIT