import { cancelable } from './cancellable-promise.utils';

type CbLike<T> = (res: (res: T) => void) => void;

export const promisify = async <T>(
  cb: CbLike<T>,
  _this?: Object
): Promise<T> => {
  return cancelable(
    new Promise<T>((res) => {
      let _cb = cb;

      if (_this) {
        _cb = cb.bind(_this);
      }

      _cb((_r) => res(_r));
    })
  );
};