Microsoft graph : UnhandledPromiseRejectionWarning: PolyFillNotAvailable: Library cannot function without fetch. So, please provide polyfill for it

Question

Microsoft graph throws the below exception when initializing the client using the access token

the access token was generated just before initializing the client & also the same token works in post-man

what is that I'm doing wrong?

code

let graphClient = graph.Client.init({
        // Use the provided access token to authenticate
        // requests
        authProvider: (done) => {
            done(null, accessToken);
        }
    });

Post-man response

Answer 1

Quoting the install guide:

import @microsoft/microsoft-graph-client into your module and also you will need polyfills for fetch like isomorphic-fetch.

Here is what you need to do.

npm install isomorphic-fetch
import "isomorphic-fetch"; OR require('isomorphic-fetch');