vitest-dynamodb-lite/lib/utils.ts

fast dynamodb mock on local for vitest

import { vi } from "vitest";

export const isPromise = <R>(p: unknown | Promise<R>): p is Promise<R> =>
  !!p && Object.prototype.toString.call(p) === "[object Promise]";

export const isFunction = <F>(f: unknown | (() => F)): f is () => F =>
  !!f && typeof f === "function";

const convertToNumbers = (
  keys: Array<string | number | symbol>,
  value: string | number,
): number | string => {
  if (!Number.isNaN(Number(value)) && keys.some((v) => v === Number(value))) {
    return Number(value);
  }

  return value;
};

// credit: https://stackoverflow.com/a/62362002/1741602
export const omit = <T extends object, K extends [...(keyof T)[]]>(
  obj: T,
  ...keys: K
): { [P in Exclude<keyof T, K[number]>]: T[P] } => {
  return (Object.getOwnPropertySymbols(obj) as Array<keyof T>)
    .concat(
      Object.keys(obj).map((key) => convertToNumbers(keys, key)) as Array<
        keyof T
      >,
    )
    .filter((key) => !keys.includes(key))
    .reduce((agg, key) => ({ ...agg, [key]: obj[key] }), {}) as {
    [P in Exclude<keyof T, K[number]>]: T[P];
  };
};

// stolen from https://github.com/testing-library/dom-testing-library/blob/master/src/helpers.js
export const runWithRealTimers = <T, R>(
  callback: () => T | Promise<R>,
): T | Promise<R> => {
  const usingFakeTimers = vi.isFakeTimers();

  if (usingFakeTimers) {
    vi.useRealTimers();
  }

  const callbackReturnValue = callback();

  if (isPromise(callbackReturnValue)) {
    return callbackReturnValue.then((value) => {
      if (usingFakeTimers) {
        vi.useFakeTimers();
      }

      return value;
    });
  }

  if (usingFakeTimers) {
    vi.useFakeTimers();
  }

  return callbackReturnValue;
};

export const sleep = (time: number): Promise<void> =>
  new Promise((resolve) => setTimeout(resolve, time));