promise-utils.ts

const getFinishedState = async (s: [string], p: Promise<any>) => {
  try {
    await p;
    s[0] = 'resolved';
  } catch (e) {
    s[0] = 'rejected';

    // Don't swallow error
    return p;
  }
};

// p-state replacement
export const state = async (p: Promise<any>): Promise<'rejected' | 'resolved' | 'pending'> => {
  const res = ['pending'] as [string];
  getFinishedState(res, p);
  await nextTick;
  return res[0] as any;
};

// p-waterfall replacement, change for loop to for of for other types of iterable
export const waterfall = (tasks: (value: any) => any, initialValue?: any): any => {
  let res = Promise.resolve(initialValue);
  for (let i = 0; i < tasks.length; i++) res = res.then(tasks[i]);
  return res;
}

// p-is-promise replacement
export const isThenable = <T>(p: any): p is PromiseLike<T> =>
  p !== null &&
  typeof p === 'object' &&
  !Array.isArray(p) &&
  Object.hasOwn(p, 'then');