Multitab Token Refresh

When using single-use refresh tokens with multiple browser tabs,
a race condition between tabs may occur when it's time to refresh.

This little package solves this problem by using the Web Locks API to synchronize requests for an access token, from multiple browser tabs.
If the access token needs refreshing, it is refreshed while the lock is held.
This ensures that a refresh token is only used once.

Additionally, this package can provide updates on login/logout events to peer tabs, so that they may transition to an appropriate state.

Setup

We use Axios as an HTTP client in the example.

``javascript
// ApiService.js
import Axios from "axios";
import {
fromJwt,
TokenService,
Tokens,
createAxiosAuthRequestInterceptor,
} from "@weareyipyip/multitab-token-refresh";

// ApiClient will be used for requests that don't require an access token
const ApiClient = Axios.create();

// you need to process your own login/refresh response body format and create a new Tokens object from it
// you can use the fromJwt helper function to do so
function authResponseToTokens(resp) {
const {
data: { access, refresh },
} = resp;
const tokens = fromJwt({ accessToken: access, refreshToken: refresh });
return tokens;
}

// define a function that can refresh tokens based on a refreshToken and returns a new Tokens object on success
function refreshTokens(refreshToken) {
return (
ApiClient.post("/refresh", null, {
headers: { authorization: Bearer ${refreshToken} },
})
// on success, map the response to a Tokens object
.then(authResponseToTokens)
// on refresh failure, rethrow the error
// note that we take care to only call setLoggedOut on 401, so that sessions are
// not logged-out on temporary errors like 503 Service Unavailable
.catch((authError, setLoggedOut) => {
if (authError?.response?.status === 401) setLoggedOut();
throw authError;
})
);
}

// Create a TokenService instance
const myTokenService = new TokenService(refreshTokens);

// on login, your need to notify the TokenService of the new status
function onLogin(response) {
myTokenService.setStatus(authResponseToTokens(response));
return response;
}

// your login function
function login(username, password) {
return ApiClient.post("/login", { username, password }).then(onLogin);
}

// AuthApiClient will be used for all requests that require an access token
const AuthApiClient = Axios.create();
const axiosAuthRequestInterceptor =
createAxiosAuthRequestInterceptor(myTokenService);
AuthApiClient.interceptors.request.use(axiosAuthRequestInterceptor);

// on logout, notify the TokenService (regardless of success)
function logout() {
return AuthApiClient.post("/logout")
.then(() => myTokenService.setLoggedOut())
.catch(() => myTokenService.setLoggedOut());
}

// now you're good to go
AuthApiClient.get("/very_secure_endpoint");
`

Reload peer tabs on login/logout

If you want all browser tabs of your application to reflect logged-in or logged-out status,
you can force a reload of peer tabs using subscribeToPeerTabUpdates.
This opt-in behavior can be enabled by simply calling this function anywhere during initialization,
for example after setting the refresh callback:

`javascript
import { subscribeToPeerTabUpdates } from "@weareyipyip/multitab-token-refresh";

const myTokenService = new TokenService(refreshTokens);
subscribeToPeerTabUpdates(myTokenService);
`

Integrate with Vuex

Example for Vue/Vuex 2, but works for Vue/Vuex 3 as well. Will work across tabs.

`javascript
// store.js
import Vue from "vue";
import Vuex from "vuex";
import { createVuexPlugin } from "@weareyipyip/multitab-token-refresh";
import { myTokenService } from "./ApiService";

Vue.use(Vuex);

export default new Vuex.Store({
plugins: [createVuexPlugin(myTokenService, "updateAuthStatus")],

state: {
loggedIn: false,
},

mutations: {
updateAuthStatus: (state, { loggedIn }) => {
state.loggedIn = loggedIn;
},
},
});
``