Problem
class User {
  async constructor(userId) {
    const user = await getUser(userId)
    this.id = user.id;
    this.name = user.name;
    this.email = user.email;
  }
  ...
}
Solution

JavaScript doesn’t allow class constructors to be async. We have to do any async actions outside of a constructor. Static class methods can help with this.

class User {
  static async init(userId) {
    const user = await getUser(userId);
    return new User(user);
  }
  constructor(user) {
    this.id = user.id;
    this.name = user.name;
    this.email = user.email;
  }
}

const me = await User.init(1)