Apollo VueJS - Token Re-authorisation

apolloExampleTokenReAuthorise.js

import {ApolloLink} from "apollo-link";
import {ApolloClient} from "apollo-client";
import {createHttpLink} from 'apollo-link-http';
import {HttpLink} from "apollo-link-http";
import {InMemoryCache} from "apollo-cache-inmemory";


const customFetch = (uri, options) => {
  
    // set a reference to the refresh promise
    this.refreshingPromise = null;

    // run the initial request
    let initialRequest = fetch(uri, options);

    // return the initial requests promise
    return initialRequest.then((response) => {
        return (response);
    }).then((json) => {

        // check if we have a none empty json
        // and if we have 403 error (Forbidden)
        if (json && json.status === 403) {

            // if we don't already have have promising
            // create one that refreshes the token
            if (!this.refreshingPromise) {
                // attach logic to get refresh token that returns a promise
                // something like:
                // this.refreshingPromise = fetch('/o/token/', { method: 'POST' })
                //  .then((refresh_token) => {
                //      return refresh_token
                //   })
                // })
            }

            // wait for refresh token to complete then here we can get the new token
            // and assigned it to `authorization` headers and re-run the same fetch
            return this.refreshingPromise.then((response) => {
                this.refreshingPromise = null;

                let newAccessToken = response.accessToken;

                options.headers.authorization = `Bearer ${newAccessToken}`;

                return fetch(uri, options);
            }).catch((errors)=>{
                // otherwise error
                // here you can also run the logout() method
                // as we have now failed again.
                console.error(errors);
                return false;
            })
        }

        // else if everything good
        // simply return the response
        return json;
    });
};

const httpLink = createHttpLink({
    uri: '/graphql',
    fetch: customFetch, // create a custom fetch
});

const authLink = new ApolloLink((operation, forward) => {
    // get the authentication token 
    let accessToken = localStorage.getItem('token');
    accessToken = accessToken ? `Bearer ${accessToken}` : null;

    operation.setContext({
        headers: {authorization: accessToken}
    });

    return forward(operation)
});

const client = new ApolloClient({
  link: authLink.concat(httpLink),
  cache: new InMemoryCache()
});