promise-utils.js

export const executeAndReturn = (fn) => {
  return (argument) => {
    fn();
    return argument;
  }
};

usage.js

// Without executeAndReturn utility

const myFn = () => console.log('my fancy calculation')
Promise.resolve('my resolved promise')
  .then((value) => { 
    myFn(); 
    return value; 
  })
  .then((promiseValue) => console.log(promiseValue));

// => "my fancy calculation"
// => "my resolved promise"

// With executeAndReturn utility
import { executeAndReturn } from 'promise-utils.js';

const myFn = () => console.log('my fancy calculation')
Promise.resolve('my resolved promise')
  .then(executeAndReturn(myFn))
  .then((promiseValue) => console.log(promiseValue));
  
// => "my fancy calculation"
// => "my resolved promise"