Resolvable.ts

export interface Resolve<T> {
  (value: T | PromiseLike<T>): Resolvable<T>;
}

export interface Reject<T> {
  (reason: T | PromiseLike<T>): Resolvable<T>;
}

export interface Resolvable<T> extends Promise<T> {
  resolve: Resolve<T>;
  reject: Reject<T>;
}

export const resolvable = <T>(): Resolvable<T> => {
  let resolve: Resolve<T>;
  let reject: Reject<T>;

  let resolvable: Resolvable<T> = new Promise<T>((_resolve, _reject) => {
    resolve = _resolve as Resolve<T>;
    reject = _reject as Reject<T>;
  }) as Resolvable<T>;

  resolvable.resolve = (value) => {
    resolve(value);
    return resolvable;
  };

  resolvable.reject = (reason) => {
    reject(reason);
    return resolvable;
  };

  return resolvable;
};