async-await-express-route.js

const asyncMiddleware = fn => (req, res, next) => {
  Promise.resolve(fn(req, res, next).catch(next);
};

const getUser = async (req, res, next) => {
  const { id } = req.params;
  const user = await User.findById(id);
}

router.get("/user/:id", asyncMiddleware(getUser));