Webtask to swap auth0 ID token for stream.io one

webtask.js

"use latest";
import jwt from 'jsonwebtoken';

export default function(ctx, cb) {
  const authSecret = ctx.data.AUTH0_CLIENT_SECRET;
  const streamSecret = ctx.data.STREAM_CLIENT_SECRET;
  const token = ctx.data.token;
  const userId = jwt.verify(token, new Buffer(authSecret, 'base64')).sub;
  const slug = ctx.data.feed;
  
  const payload = {
    resource: '*',
    action: '*',
    feed_id: `${slug}${userId}`
  };
  
  const signed = jwt.sign(payload, streamSecret, { noTimestamp: true });
  
  cb(null, signed); 
}