README.md

jwt-utils

A small package to perform JWT token operations (store, get, decode, get expiration date, check if expired, validate, remove from storage).

Installation

yarn add @around25/jwt-utils

Usage

Initialize the package and then import in wherever you need it. The constructor takes a single config object as parameter. The storageSystem property is required.

import TokenService from '@around25/jwt-utils'

const TokenUtils = new TokenService({
  storageSystem: window.localStorage
});

export default TokenUtils

In the React environment, it can be either window.localStorage or window.sessionStorage. And it's totally synchronous.

store(token)

Stores token using the specified storage system. Token must be a string.

// Take a properly formatted JWT token
const token = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6IjEiLCJuYW1lIjoiSm9obiBEb2UiLCJleHAiOjE1MjU3MDAxNjE1NjJ9.qGB98H-4th9E0yTVHH235A4kCgFyKt5jIVgekk4fcp4'

TokenUtils.store(token);

get()

Retrieves the stored token if set, undefined otherwise.

const token = TokenUtils.get();

// eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6IjEiLCJuY...

decode(token)

Decodes a token. A falsy token will return {}.

const decodedToken = TokenUtils.decode(token);

// {
//   id: 1,
//   name: "John Doe",
//   exp: 1525700161562
// }

getExpirationDate(token)

Returns expiration date as unix timestamp (ms) or null if the exp property is not defined in the decoded token.

const expirationDate = TokenUtils.getExpirationDate(token);

// 1525700161562

isExpired(token)

Returns a boolean value specifying if token is expired or not.

const isExpired = TokenUtils.isExpired(token);

isValid(token)

Checks if token is valid, simply by checking its existence. You can optionally use a validation function as a secondary param. In that case, the validation function should return a boolean value.

const isValid = TokenUtils.isValid(token, validationFunc);

remove(token)

Removes token from storage

TokenUtils.remove(token);

Usage with React Native

In the React Native environment, store, get and remove methods return promises (due to the async nature of the storage system).

import { AsyncStorage } from 'react-native'
import TokenService from 'jwt-utils'

export default new TokenService({
  storageSystem: AsyncStorage
});

const result = await TokenUtils.store(token);
// true

const token = await TokenUtils.get();
// eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6IjEiLCJuY...

Dependencies

This package depends on jwt-decode for token decoding.