some helper functions

helpers.ts

function randomBoolean() {
  return Math.random() < 0.5;
}

function chunkArray<T>(array: T[], chunkSize: number): T[][] {
  return Array.from(
    { length: Math.ceil(array.length / chunkSize) },
    (_, index) => array.slice(index * chunkSize, (index + 1) * chunkSize),
  );
}

async function simulateHttpRequest<T>(payload: T): Promise<T> {
  // return dummyPromise()
  //   .then(() => fetch("https://jsonplaceholder.typicode.com/posts"))
  //   .then((res) => res.json())
  //   .then(() => payload);
  return fetch("https://jsonplaceholder.typicode.com/posts")
    .then((res) => res.json())
    .then(() => payload);
}

function bytes2MB(bytes: number): number {
  return bytes / (1024 * 1024);
}

async function dummyPromise(dur: number = -1) {
  const maxSeconds = 3;
  const defaultDur = Math.random() * 1000 * maxSeconds;
  return new Promise((resolve, reject) => {
    setTimeout(
      () => {
        if (randomBoolean()) {
          resolve(undefined);
        } else {
          reject("some reason");
        }
      },
      dur < 0 ? defaultDur : dur,
    );
  });
}