JavaScript's Array.map function failing to return a value

Here is a snippet of code from an api endpoint in nextJS that retrieves the corresponding authors for a given array of posts. Each post in the array contains an "authorId" key. The initial approach did not yield the expected results:

const users = posts.map(async (post) => await prisma.user.findUnique({ where: { id: post.authorId }}));

Dissatisfied with the outcome, I decided to try a more traditional method which proved successful:

    const users = []
    for (let i = 0; i < posts.length; i++) {
            const user = await prisma.user.findUnique({
                where: {
                    id: posts[i].authorId,
                },
            });
            users.push(user);
        }

I initially suspected the issue might be related to the arrow syntax or implicit return, so I made adjustments as follows:

        const getUsers = async (post: Post) => {
            const user = await prisma.user.findUnique({
                where: {
                    id: post.authorId,
                },
            });
            console.log(user);
            return user;
        };
        const users = posts.map(getUsers);

Although the user object was successfully logged to the console, it still did not return the expected value, resulting in an array filled with empty objects matching the size of the posts array. Can anyone identify where I may have gone wrong?

Note that in this scenario, I am utilizing Prisma as an ORM.

Answer №1

The two code snippets you provided do not have the same functionality.

When using the getUsers function, it returns a Promise since it is an asynchronous function that resolves with a user. Therefore, in your last example, the variable users contains an array of promises. To achieve your intended outcome, you should consider utilizing the following code snippet:

const users = await Promise.all(posts.map(getUsers));

This allows you to concurrently retrieve all users from the array of promises.

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Issue encountered in Angularjs during upgrade process from version 1.2.27 to 1.4.7

Recently, I upgraded my app from using AngularJS 1.2.27 to version 1.4.7, but now I am encountering an error in the AngularJS file. SyntaxError: Unexpected token : (angular.js:12477) at Function (native) at Object.sd. ...

Integration of Mocha with WebStorm

WebStorm offers a useful feature that adds a small arrow next to describe() and it() keywords when writing tests with Mocha, allowing for easy manual execution. However, there is a challenge: I require additional setup before each test, leading me to use ...

Is there a way to serve server-side rendered content exclusively to search engine crawlers like Google Bot, without SSR for regular users in Next.js?

With a staggering number of users visiting the site every day, we are making strides to enhance our visibility on Google by implementing SSR (which may sound unbelievable) and achieving a richer preview when content is shared on messaging platforms. As th ...

Is it possible to utilize the identical schema.prisma file on two distinct servers in order to produce the exact Prisma client?

Can I use Prisma to read and write to my database from an API server, as well as have a separate stand-alone node server that only writes to the database without exposing any endpoints? The documentation I've reviewed so far indicates that you need to ...

Passing backend variables/data to AngularJS in Express JS

As a newcomer to express js, I appreciate your patience with me. I've been diving into "MEAN Web Development" by Amos Q. Haviv and finding it to be an excellent read. However, there's one part that's leaving me puzzled. It seems that in or ...

Is it possible for .getElementByClassName to identify Ajax.GET elements?

I've run into a problem that I need help with: The issue arises when I have an API that makes an Ajax GET request. In the success function, it creates a button, a div, and several span elements with information inside, each with its own class. The GE ...

Animation showing on the progress bar is not correctly halted

I am encountering a problem with handling an animation of a progress bar in my code. The issue arises when I pause the animation, as it seems to slightly backtrack instead of pausing at the correct position upon clicking a button. Can someone help identify ...

Is there a way to retrieve the chosen value from a select element?

How do I retrieve the chosen value from a select element? In my select.component.ts file: export class PfSelectComponent implements OnInit { constructor() { } ngOnInit() { } @Input() options : Array<Object>; } Contents of select.compon ...

modified a file using express framework

I am attempting to utilize mongoDB in order to update the status of an existing document. Despite my backend successfully receiving the routes, the mongoDB update process is not functioning as expected. router.post('/orders_drivers', function (r ...

Generating a string indicating the range of days chosen

Imagine a scenario where there is a selection of days available to the user (they can choose multiple). The list includes Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, and Saturday, each with an associated number from 0 to 6. For instance, Sunday ...

Utilizing for loop and specific string selectors in an undefined AJAX post request

Greetings fellow developers! I have been exploring jquery/ajax and here is what I've put together: $(function() { $("#moreAdd").click(function() { var dataString = []; var selector = '#repeat0'; var row; for(var i=0;$ ...

having trouble compiling a react js file with webpack

One of my files, app.js, contains the following code snippet: handlePageClick = (data) => { let selected = data.selected; let offset = Math.ceil(selected * this.props.perPage); this.setState({offset: offset}, () => { this.setStat ...

The best location for storing Typescript files within an ASP.NET Core project

My Typescript app is built on AngularJS 2 with ASP.NET Core, and currently I store my TS files in the wwwroot directory. While this setup works well during development, I am concerned about how it will function in production. I aim to deploy only minified ...

Designing a photo frame slider for a unique touch

My skills in javascript and jQuery are limited, but I am looking to create a customizable slider. While exploring options like Flexslider (), I found it challenging to meet the following specifications: Eliminate color gaps between thumbnails Enable thu ...

Why does my jQuery code target all the text values?

Looking to grab a specific table cell number and multiply it by an input value on focusout, but having trouble with the selector grabbing all cells with "front" in the name. Check out the code below: jquery $(document).ready(function(){ $(".percent") ...

Can Vuejs functions be triggered using a jQuery event trigger?

I am currently attempting to trigger a change event within a Vue component. Within the component template, there is a select element. When I try to use jQuery to trigger a change event on this element, the Vue component does not seem to detect it. Here i ...

Top method for transferring the result of a function to descendant components in Vue

In my parent component, I have a data object named config structured like this: data() { return { config: { Groups: [ { name: "A", Types: [ { mask: 1234, name: ...

Issues with router middleware functionality in Node.js hinder proper operations

Currently, I am working with Nodejs and utilizing "Express js". One of the tasks at hand involves implementing a "Router Middleware" function. With my current code setup, whenever I access "http://localhost:3000", the "router middle" functionality is tri ...

What steps should I follow to enable webview autocomplete for a login form on Ionic's Capacitor in iOS?

I am trying to figure out how to activate the autocomplete feature for a login form in Capacitor when using Ionic React. The issue arises when bundling the web app in Capacitor, as the autocomplete functionality seems to disappear. Although it works on Saf ...

Leveraging the reset function with the $meteor.object

Currently, I am working on a straightforward controller utilizing the angular-meteor starter project. controller("PartyDetailsCtrl", function($scope, $stateParams, $meteor) { $scope.party = $meteor.object(Parties, $stateParams.partyId); $scope.save = ...