generateDeferredPromise.ts

function generateDeferredPromise<T>(): {
  promise: Promise<T>;
  reject: (reason?: unknown) => void;
  resolve: (value: T | PromiseLike<T>) => void;
} {
  let resolve!: (value: T | PromiseLike<T>) => void;
  let reject!: (reason?: unknown) => void;
  const promise = new Promise<T>((res, rej) => {
    [resolve, reject] = [res, rej];
  });
  return { promise, reject, resolve };
}