Promise class that returns promises that can be directly resolved or rejected via `.resolve(data)` or `.reject(data)`

rpromise.js

'use strict'

// prints "0ms", then "1000ms", then "2000ms", ...
function main () {
  for (let i = 0; i < 5; i++) {
    const pr = new RPromise()
    const millis = i * 1000

    setTimeout(() => pr.resolve(`${millis}ms`), millis)
    pr.then(data => console.log(data))
  }
}

// creates promises with resolve() and reject() methods
class RPromise {
  constructor () {
    const promise = new Promise((resolve, reject) => {
      this.resolve = resolve
      this.reject = reject
    })

    this.then = (fn) => promise.then(fn)
    this.catch = (fn) => promise.catch(fn)
  }
}

if (require.main === module) main()