Deferred in ES6 Promise

createDeferred.ts

interface IDeferred<T> {
  promise: () => Promise<T>,
  resolve: (result: T) => void,
  reject: (error: Error) => void
}

function createDeferred<T>(): Promise<IDeferred<T>> {
  return new Promise<IDeferred<T>>(resolveCreate => {
    const promise = new Promise<T>(function (resolve, reject) {
      resolveCreate({ promise: () => promise, resolve, reject });
    });
  });
}

function Deferred<T>() {
  let resolve, reject
  const promise = new Promise<T>((resolve0, reject0) => {
    resolve = resolve0
    reject = reject0
  })
  return {
    reject,
    resolve,
    promise
  }
}