Articles page 1

MongoDB GeoJSON Schema Validation

If you want to save the location of someone, something, or somewhere, you'll need to store its coordinates. In this article we'll be looking…

How To Mock Fetch in Jest

Making HTTP requests in tests isn't a great idea in most situations... it can slow your tests down, is unreliable, and the API you are…

How to use Reduce in JavaScript

The reduce function of an Array is one of the most versatile functions in JavaScript. With it you can accomplish a lot of the functions…

How to Publish an NPM Package

Publishing an NPM package with TypeScript has never been easier with the help of tsdx , a wonderful package from Jared Palmer , who also…

Leaflet Marker Clustering

Performance can begin to degrade pretty quickly when you are trying to show large amounts of data on a map. Even at hundreds of markers…

Google Maps Marker Clustering

Performance can begin to degrade pretty quickly when you are trying to show large amounts of data on a map. Even at hundreds of markers…

Mapbox Marker Clustering

Performance can begin to degrade pretty quickly when you are trying to show large amounts of data on a map. Even at hundreds of markers…

Replacing Redux with React Hooks

Redux has been the go-to way to manage state within your React application for years. It's popularity is due in large part because when it…

How Does SWR Work?

SWR is a great package from Zeit to help make it easier to fetch remote data with hooks. It is based on the stale-while-revalidate RFC…

Secrets and Environment Variables in Next.js and Now

Zeit has great documentation, but it took me a while to understand the difference between environment variables (secrets) on the serverless…

Serverless OG Image

If you've ever pasted a URL from an article on dev.to into Slack, Twitter, Facebook or LinkedIn, you'll notice they have an awesome social…

Iterate over Objects in JavaScript

How do you iterate over objects in JavaScript? In this article we'll answer this question by showing 3 alternatives. The data we'll be using…

Tagged Template Literals

I kept seeing Tagged Template Literals in a number of popular libraries, but I didn't understand how they worked. This article explores…

Using the useEffect hook

useEffect is meant to handle any sort of "side effect" (making a change in some external system, logging to the console, making an HTTP…

Generating TypeScript Types from GraphQL Schema in Apollo

GraphQL is a typed language, so why redefine all of the types ourselves inside our TypeScript code when we should be able to take…

Async Axios in React Testing Library

In this article we'll take a look at how to handle async code in React Testing Library, specifically at how to test and mock a call using…

Firing Events in React Testing Library

In this article we'll see how to fire and test events in our React components using the React Testing Library. With React Testing Library it…

Introduction to the React Testing Library

React Testing Library is an amazing yet simple testing library from Kent Dodds . It works alongside the testing library Jest to provide…

React Hooks with Apollo GraphQL

With React 16.7 we were introduced to hooks . A way to allow things like state, refs, and lifecycle functions to live inside functional…

Using apollo-link-rest to use GraphQL with your RESTful endpoints

So you've updated your React code to use GraphQL, but there's those 2 RESTful API endpoints that you still have to integrate with... what do…

React and Purity

React gets its name from being reactive to changes in your data. When data changes, the UI reacts to those changes to re-render the page to…

How to use GraphQL with React

GraphQL is an amazing new(ish) paradigm for communicating with APIs, made popular by Facebook but since then used by many companies…

Map, Reduce, Filter, and Pie Charts

Data comes in all sorts and sizes, and one of the key skills a developer can have is how to convert it into the required format and shape…

Mocking Axios in Jest + Testing Async Functions

In our tests we don't want to perform an actual HTTP request. To start with it is slow, but there are certain calls you really can't make…

Testing Asynchronous Components with Mocks in Jest

In this article below we will test a component which runs asynchronous code inside of its componentDidMount lifecycle event. We'll look at…

Introducing the React Context API

The new React Context API is touted (at least on Twitter and a number of articles) as solving the need to use a state management tool…

Error Boundaries and Render Props

Error boundaries were introduced in React 16.2 and provide a sort of declarative try/catch pattern for you to handle errors which occur…

Testing React with Jest, Enzyme, and Sinon

In this article we'll look at how to get up and running with testing React in a create-react-app . We'll look at how to configure your…

Introduction to React Motion Tutorial

React Motion is an animation library loved within the React community. I have to say that having some experience with libraries like GSAP…

Easy MobX and Redux Comparison

In this article/video we'll start with a simple React app made with create-react-app that uses component state (setState) as its state…