This tutorial demonstrates how to setup testing with Mocha, Chai, and Sinon in Node.js. Whereas the previous tutorial has already shown you how to setup your Node.js application, this tutorial sets up a testing environment for your Node.js project. Let's dive into it by setting up Mocha with Chai and Sinon as testing framework. Node.js with Mocha…
Since React Hooks have been released, function components can use state and side-effects. There are two hooks that are used for modern state management in React: useState and useReducer. This tutorial goes step-by-step through a useReducer example in React for getting you started with this React Hook for state management. Reducer in React If…
The concept of a Reducer became popular in JavaScript with the rise of Redux as state management solution for React . But no worries, you don't need to learn Redux to understand Reducers. Basically reducers are there to manage state in an application. For instance, if a user writes something in an HTML input field, the application has to manage…
Since React Hooks have been released, function components in React can use state and side-effects. There are two main hooks that are used for modern state management in React : useState and useReducer. This tutorial doesn't explain both React hooks in detail, but explains their different use case scenarios. There are many people who ask me…
If you are new to React, most likely you want to know how to display a list of items in React's JSX syntax. This tutorial for List components in React gives you a step by step walkthrough on how to render a list of simple primitives, how to render a list of complex objects, and how to update the state of your list in React. How to display a list of…
There are quite a lot of articles about React out there speaking about controlled and uncontrolled components without explaining them. It has been quite similar for my articles, whereas I always tried to add at least one or two sentences explaining them, but in the end, I thought it would be great to have a brief tutorial just showing a simple…
Everyone dealing with React knows about this warning: Warning: Each child in a list should have a unique "key" prop. It shows up in your development tools of your browser and it's one of the warnings you encounter very early in your React career. The following list component results in this warning: The warning says we only need to add a key…
If you haven't used state management excessively in React Function Components , this tutorial may help you to get a better understanding of how React Hooks -- such as useState, useReducer, and useContext -- can be used in combination for impressive state management in React applications. In this tutorial, we will almost reach the point where…
So much has been said about the appropriate way to style modern web apps. There's the general and oldest method of styling at document level - creating a style.css file and linking to it in the HTML file and more recently the method of styling in JS. This is popularly known as CSS-in-JS. CSS-in-JS is a styling approach that abstracts the CSS…
React Hooks were introduced to React to make state and side-effects available in React Function Components. Before it was only possible to have these in React Class Components; but since React's way of implementing Components has changed over the years , we have the class component's features available with React Hooks in React Function Components…
