JSFiddle - React, Tailwind, and code Playground

JavaScript

var maybePromise = Math.random() > 0.5 ? 10 : Promise.resolve(10);

var definitelyPromise = Promise.resolve(maybePromise);

// equivalent to
var definitelyPromise2 = new Promise(function(fulfill, reject) {
  if (maybePromise instanceof Promise) {
    maybePromise.then(fulfill, reject);
  } else {
    fulfill(maybePromise);
  }
});

// also equivalent?
var definitelyPromise3 = new Promise(function(fulfill, reject) {
  if (maybePromise instanceof Promise) {
    fulfill(maybePromise);
  } else {
    fulfill(maybePromise);
  }
});

definitelyPromise3.
then(function(x) {
  console.log('Accepted' + x);
}).
catch(function(reason) {
  console.log("Rejected:" + reason)
});