JAVASCRIPT

what is a promise

// Promise is a special type of object that helps you work with asynchronous operations.
// Many functions will return a promise to you in situations where the value cannot be retrieved immediately.

const userCount = getUserCount();
console.log(userCount); // Promise {<pending>}

// In this case, getUserCount is the function that returns a Promise. If we try to immediately display the value of the userCount variable, we get something like Promise {<pending>}.
// This will happen because there is no data yet and we need to wait for it.

is promise

import isPromise from 'is-promise';

isPromise(Promise.resolve());//=>true
isPromise({then:function () {...}});//=>true
isPromise(null);//=>false
isPromise({});//=>false
isPromise({then: true})//=>false