Is it possible to await a class in javascript? [duplicate]

Question

The keyword await makes JavaScript wait until that promise settles and returns its result.

I noticed its possible to await a function

var neonlight = await neon();

Is it possible to await a class?

Example

var neonlight = await new Neon(neon_gas);

Answer 1

Technically .. Yes, If the constructor returns a Promise and as long as the await is inside an async function, here's an example ( might not be the best, actually it's a bad practice to have a constructor function return a Promise , but it's just to get this to work ):

class Test {
  constructor() {
    return new Promise((res, rej) => {      
      this.getData().then(({userId, title}) => {
        this.userId = userId;
        this.title = title;
        
        res(this);
      });
    });
  }
  
  getData(){
    return fetch('https://jsonplaceholder.typicode.com/todos/1')
      .then(response => response.json())      
  }
  
  greet(){    
    console.log('hello');
  }
}


(async() => {
  const x = await new Test();
  console.log(x.userId, ' : ', x.title);
})();