Node 10 memory leak with domains & Express

test.js

'use strict';

const domain = require('domain');
const app = require('express')();

app.use((req, res, next) => {
  let requestDomain = domain.create();

  requestDomain.add(req);
  requestDomain.on('error', next);

  requestDomain.run(() => {
    next();
  });
});

app.get('/', (req, res) => {
  req.cachedPromise = new Promise(resolve => {
    let tenMebibyteString = 'a'.repeat(10 * 1024 * 1024);
    resolve(tenMebibyteString);
  });

  res.send('hi');
});

app.listen(5000);