OAuth2: oauth2Guard: Set access token on Express request

[vlaurin]

As part of the oauth2 guard, when the access token is extracted, set it as property req.accessToken so it can be consumed easily by subsequent middlewares.

Example

import express from 'express';
import {
  cachedJwtKeySupplier,
  defaultJwtKeySupplier,
  defaultJwtVerifier,
  defaultUserInfoRetriever,
  oauth2Guard,
} from '@quickcase/node-toolkit';

const jwtKeySupplier = cachedJwtKeySupplier()(defaultJwtKeySupplier({jwksUri: 'https://...'}));

const app = express();

app.use(oauth2Guard({
  jwtVerifier: defaultJwtVerifier(jwtKeySupplier),
  userInfoRetriever: defaultUserInfoRetriever({userInfoUri: 'https://...'}),
}));

app.use((req, res, next) => {
  // req.accessToken = 'eyeyeye...'; <--- new property
  // req.grantedAuthorities = ['caseworker', 'caseworker-jid'];
  // req.userClaims = {
  //   sub: '',
  //   ...
  // };
  next();
});