@47ng/codec

Universal conversion of Uint8Array from/into UTF-8, base64url and hex in the browser and Node.js

Usage no npm install needed!

<script type="module">
  import 47ngCodec from 'https://cdn.skypack.dev/@47ng/codec';
</script>

README

@47ng/codec

NPM MIT License Continuous Integration Coverage Status Dependabot Status

Universal conversion of Uint8Array from/into UTF-8, base64url and hex in the browser and Node.js

Installation

$ yarn add @47ng/codec
# or
$ npm i @47ng/codec

Features

Available codecs:

Watch out ! utf8 uses a different convention than the other codecs (encode and decode are swapped), to reflect how TextEncoder and TextDecoder behave.

Support

  • Node.js: >=11.x
  • Browser: See caniuse for TextEncoder / TextDecoder

Examples

import { b64, hex, utf8 } from '@47ng/codec'

b64.encode(utf8.encode('Hello, World !')) // SGVsbG8sIFdvcmxkICE=
hex.encode(b64.decode('SGVsbG8sIFdvcmxkICE=')) // 48656c6c6f2c20576f726c642021
utf8.decode(hex.decode('48656c6c6f2c20576f726c642021')) // Hello, World !

b64.decode('SGVsbG8sIFdvcmxkICE=') // <Buffer 48 65 6c 6c 6f 2c 20 57 6f 72 6c 64 20 21>

Documentation

UTF-8

  • utf8.encode: Convert an UTF-8 string into an array of bytes (Uint8Array)
  • utf8.decode: Convert an array of bytes into an UTF-8 string

Examples:

import { utf8 } from '@47ng/codec'

const uint8Array = utf8.encode('Hello, World!')
// Uint8Array [72, 101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33]

const backToText = utf8.decode(uint8Array)
// 'Hello, World!'

Base 64

  • b64.encode: Convert an array of bytes into a base64url string
  • b64.decode: Convert a base64 string into an array of bytes
  • b64.urlSafe: Convert a standard base64 string to base64url
  • b64.urlUnsafe: Convert a base64url string to standard base64 dictionary

Note: For decoding, any dictionary is supported, and trailing padding (=) is optional.

Examples:

import { b64, utf8 } from '@47ng/codec'

const uint8Array = b64.decode('8J-Ri_CfjI0')
// Uint8Array [240, 159, 145, 139, 240, 159, 140, 141]

// Encoding always emits padding
const backToBase64 = b64.encode(uint8Array)
// '8J-Ri_CfjI0='

const asText = utf8.decode(uint8Array)
// '👋🌍'

Hex

  • hex.encode: Convert an array of bytes into a hex string
  • hex.decode: Convert a hex string into an array of bytes

Note: Decoding accepts any case (lowercase, uppercase, mixed).

Examples:

import { hex } from '@47ng/codec'

const uint8Array = hex.decode('48656C6C6F2C20576f726c642021')
// Uint8Array [72, 101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33]

// Encoding is always lowercase
const backToBase64 = hex.encode(uint8Array)
// '48656c6c6f2c20576f726c642021'

Utilities

The library exports convenience methods for hex to/from base64 conversions:

import { hexToBase64url, base64ToHex } from '@47ng/codec'

const hex = base64ToHex('SGVsbG8sIFdvcmxkICE=')
// 48656c6c6f2c20576f726c642021

const b64 = hexToBase64url('48656c6c6f2c20576f726c642021')
// SGVsbG8sIFdvcmxkICE=

As well as encoder / decoder objects with strong TypeScript types, to help you build your own encoders & decoders:

import { encoders, decoders, Encoding } from '@47ng/codec'

// type Encoding = 'base64' | 'utf8' | 'hex'

function convert(
  input: string,
  inputEncoding: Encoding,
  outputEncoding: Encoding
): string {
  const decoder = decoders[inputEncoding]
  const encoder = encoders[outputEncoding]
  return encoder(decoder(input))
}

convert('Hello, World!', 'utf8', 'base64')
// SGVsbG8sIFdvcmxkICE

convert('Hello, World!', 'utf8', 'hex')
// 48656c6c6f2c20576f726c642021

License

MIT - Made with ❤️ by François Best - Donations welcome 🙏