dmikester1•2y ago

✅ – dmikester1 – 16-27 Oct 12

Once again, here I am struggling with async/await and promises. I have a Node endpoint that ran a bunch of code to read some files from a directory and do some processing and it was all working just fine. Then I realized I needed to abstract that code out so I could call it from multiple places. And now I cannot get a result back from that endpoint. I know it has to do with how I am handling the promises.

19 Replies

dmikester1•2y ago

Here is the endpoint code:

router.get('/getMisfitCount', async (req, res) => {
    console.log('getting misfit count...');
    let misfitCountData = null;
    try {
        misfitCountData = await getMisfitCount();
        console.log({ misfitCountData });
    } catch (e) {
        console.log({ e });
    }
    res.send(misfitCountData);
});

router.get('/getMisfitCount', async (req, res) => {
    console.log('getting misfit count...');
    let misfitCountData = null;
    try {
        misfitCountData = await getMisfitCount();
        console.log({ misfitCountData });
    } catch (e) {
        console.log({ e });
    }
    res.send(misfitCountData);
});

and here is getMisfitCount():

const getMisfitCount = () => {
  const misfitsFolder = process.env.MISFITS_FOLDER;

  const EXTENSION = '.json';
  fs.promises.readdir(misfitsFolder)
    .then((files) => {
      const targetFiles = files.filter((file) => {
        return path.extname(file).toLowerCase() === EXTENSION;
      });
      let misfitReasons = {};
      targetFiles.forEach((file, index) => {
      const rawdata = fs.readFileSync(misfitsFolder + '/' + file);
      const misfitData = JSON.parse(rawdata);
      // some more logic/processing here
      console.log('sending back results');
      return { count: 5, misfitResultsMsg: 'hi there' };
})
.catch((e) => {
  console.log({ e });
  return { count: 0, misfitResultsMsg: '' };
});
};

const getMisfitCount = () => {
  const misfitsFolder = process.env.MISFITS_FOLDER;

  const EXTENSION = '.json';
  fs.promises.readdir(misfitsFolder)
    .then((files) => {
      const targetFiles = files.filter((file) => {
        return path.extname(file).toLowerCase() === EXTENSION;
      });
      let misfitReasons = {};
      targetFiles.forEach((file, index) => {
      const rawdata = fs.readFileSync(misfitsFolder + '/' + file);
      const misfitData = JSON.parse(rawdata);
      // some more logic/processing here
      console.log('sending back results');
      return { count: 5, misfitResultsMsg: 'hi there' };
})
.catch((e) => {
  console.log({ e });
  return { count: 0, misfitResultsMsg: '' };
});
};

when I log out misfitCountData in the endpoint, it is undefined and gets output before I see sending back:...

Unknown User•2y ago

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dmikester1•2y ago

targetFiles gets used a few lines down: targetFiles.forEach((file, index) => {

Unknown User•2y ago

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dmikester1•2y ago

I understand that. I am not accessing targetFiles outside the function.

Unknown User•2y ago

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dmikester1•2y ago

that }); is closing the files.filter block

Unknown User•2y ago

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dmikester1•2y ago

yeah, sorry about that

Unknown User•2y ago

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dmikester1•2y ago

shoot, i deleted my return when i was cleaning up my code

Unknown User•2y ago

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dmikester1•2y ago

i edited the function to show my return i see 'sending back results' after i see 'getting misfit count...'

Unknown User•2y ago

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dmikester1•2y ago

ohhh, so you are saying i need to do return fs.promises.readdir(misfitsFolder)....

Unknown User•2y ago

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dmikester1•2y ago

holy crap, that was it! thank you so much!!! struggled way too long on that one! 🙂

reactibot•2y ago

This question has an answer! Thank you for helping 😄 If you have a followup question, you may want to reply to this thread so other members know they're related. https://discord.com/channels/102860784329052160/565213527673929729/1029792352363106324

reactibot•2y ago

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