How to get result from Promise?

Question

JavaScript

Hello.
The following structure does not work:

async function openDb() {
      return await window.indexedDB.open('test1', 1)
  }

  openDb().then(data => {
    console.log(data.result)
  }).catch(e => {
    console.log(e)
  })

Mistake:

Failed to read the 'result' property from 'IDBRequest': The request has not finished.

BUT it works like this:

async function openDb() {
      return await window.indexedDB.open('test1', 1)
  }

  openDb().then(data => {
    setTimeout(function() {
      console.log(data.result)
    }, 1000)
  }).catch(e => {
    console.log(e)
  })

How to remove the crutch in the form of setTimeout and make this case return result to me?