Are you facing challenges using a function that returns a promise inside a forEach loop due to the asynchronous nature of the function? It seems like the forEach loop completes before the promise can finish fetching or manipulating the data.
Below is a code snippet highlighting this issue:
var todaysTopItemsBySaleFrequency = [];
listOfItemIdsAndSaleFrequency.forEach((item) => {
Product.findById(item.itemId).then((foundItem) => {
var fullItemData = foundItem.toJSON();
fullItemData.occurrences = item.occurrences;
todaysTopItemsBySaleFrequency.push(fullItemData);
});
});
return res.status(200).json(todaysTopItemsBySaleFrequency);
The array todaysTopItemsBySaleFrequency is returned to the client empty because the findById function from mongoose returns a promise and does not fully populate the array before sending the response back to the client.