promise.finally.without.finally.js

const promise = new Promise(resolve => {
  setTimeout(()=>resolve('success'));
});

const startOperation = () => { console.log('start'); };
const finishOperation = () => { console.log('finish'); };

startOperation();

promise
.then(
  result => { 
    console.log('success', result); 
    finishOperation(); // Finish in success branch 
  }, 
  error => { 
    console.log('success', error); 
    finishOperation(); // Finish in fail branch 
  }
);