fetch-retry-simple.js

// Нужно модифицировать метод fetch,
// добавив ему возможность автоматической переотправки запроса в случаи ошибки

const fetchMockReject = () => {
  return new Promise((_, reject) => {
    setTimeout(() => {
      reject("timeout error");
    }, 1000);
  });
};

//recursion 1
const withRetry1 = (retryCount) => {
  let attempts = 0;

  return new Promise((resolve, reject) => {
    const tryFetch = () => {
      attempts++;
      return fetchMockReject()
        .then((resp) => {
          resolve(resp);
        })
        .catch((err) => {
          if (attempts !== retryCount) {
            tryFetch();
          } else {
            reject(err);
          }
        });
    };
    tryFetch();
  });
};

//recursion 2
const withRetry = async (retryCount) => {
  try {
    return await fetchMockReject();
  } catch (e) {
    if (retryCount === 0) {
      throw e;
    } else {
      console.log("retries left", retryCount);
      return withRetry(retryCount - 1);
    }
  }
};

//while
const withRetry2 = (retryCount) => {
  let attempts = 0;

  return new Promise((resolve, reject) => {
    while (attempts < retryCount) {
      console.log("retry number", attempts + 1);
      attempts++;
      fetchMockReject()
        .then((resp) => resolve(resp))
        .catch((e) => {
          if (attempts === retryCount) {
            reject(e);
          }
        });
    }
  });
};

withRetry(3)
  .then(() => console.log("resolved"))
  .catch((error) => console.log(error));