async-await-sample.js

// Async function
var getNum = function(){
  return new Promise((resolve, reject) => {
    // resolve(1);
    reject('not found');
  });
}

// A function that contains an async-call
async function asyncFun (){
  var value = await getNum()
    .then(x => x + 1)
    .then(x => x + 1)
    .then(x => x + 1)
    .catch(err => Object({error: err}));
  return value;
}

// Invoke the function
asyncFun()
  .then(r => console.log(r))
  .catch(r => console.err(r));