Fetch returns null but after page refresh returns object. How to fix it?

I have an array of 500 posts id. I need to get an array of the first 100 posts. So I do the following:

BASE_URL = 'https://hacker-news.firebaseio.com/v0'

    const checkResponse = (response: Response) => {
      return response.ok ? response.json() : Promise.reject(`Some error`);
    const fetchStoryIdList = async (): Promise<any> => {
      try {
        const response = await fetch(`${BASE_URL}/newstories.json`);
        const idJson: number[] = await checkResponse(response);
        return idJson;
      } catch (error) {
        const fetchStoryList = async () => {
          const idList = await fetchStoryIdList(); // idList is an array of 500 ids
          const promises: IStory[] = idList.slice(0, 100).map(async (id: number) => {
            try {
              const response = await fetch(`${BASE_URL}/item/${id}.json`);
              const storyData: IStory = await checkResponse(response);
              return storyData;
            } catch (err) {
          const storyList = await Promise.all(promises);
          console.log('storyList:', storyList);
          return storyList;


Sometimes API call for a single post data returns null. So I get an array of posts and null. Then its renders in component and crashes because of null. After app crashes I manually refresh page and API calls fire again but this time everyting is fine.

For exapmple fetch request for post with id 28359987 returns null but after I refresh page new Api call returns post for the same id…after a while a get null again for another id…then refresh page and null is gone. How to fix that?

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You might have had an api error where it fails for a certain request. Although as can be seen in this codesandbox example – it’s always working https://codesandbox.io/s/crazy-knuth-dbldy?file=/src/App.tsx

As for removing the null value you can append .filter(Boolean) since the null results are useless to you

// don't forget those () around await
const storyList = (await Promise.all(promises)).filter(Boolean)