Course overview

How to work with course materials

Introduction

Setting up Developer Environment

Setting up Initial Project

How to Use ESLint and Prettier Together in a React Project

How to Configure React to Use TypeScript

How to Add Jest to a React Project for Automated Testing

Setting up developer environment

Building React Hooks: API Considerations and Best Practices

How to Implement a Custom useBoolean React Hook

Testing a Custom useBoolean Hook With React Testing Library

How to Implement a Custom useMap Hook With Tests

How to Quickly Import Custom React Hooks With an Index File

Implement an Object Returning API With a react-hanger Clone

Development of custom hooks

CommonJS vs ES6: An Intro to JavaScript Module Systems

What is Transpilation? An Intro to Transpilers vs Compilers

An Intro to Transpilers: ESBuild, Babel, and SWC Compared

What are Babel Transforms and Plugins?

A Beginner's Guide to JavaScript Bundlers

How to Simplify Bundling React Code With Microbundle

How to Add TypeScript Build Steps to React

How to Implement Babel Build Steps in a React App

Conclusion

Preparing code for publishing

Add Continuous Integration to a React Build With GitHub Actions

How to Automatically Generate a React App Changelog

How to Publish a React Library to NPM With GitHub Actions

Publishing the Code

In this course we’ll build a set of custom reusable hooks, a mini react-hanger clone, essentially going from nothing to a fully-automated publishing pipeline that follows the best practices.  We will cover common Hooks APIs every React developer should know, then dive straight into implementing Custom React Hooks, similar to what you will find in leading React libraries in the open source React ecosystem.

## Why this course
React Hooks promise to eliminate the difficulties of sharing state without writing class-based components. The challenge is that Hooks do away with the lifecycle methods and class-based semantics of state management that many React developers were familiar with.  Learning React Hooks on your own can be time consuming, confusing and frustrating.  With that in mind, The newline Guide to Creating a React Hooks Library, was created to provide a complete tutorial that fully covers React Hooks.  Within a few hours you'll have a strong grasp on React Hooks and how to implement them.

## Course Topics
This course packs practical hands-on-instruction using and building React Hooks, along with the best practices you need to build wider React Hooks libraries others across your organization can use.
The first module provides an overview of the React Hooks library project we’ll build, and we'll set up a complete environment with tools for library development.
The subsequent modules then take you through building with React Hooks and creating your React Hooks library, including:
- Hooks API fundamentals
- Developing custom React Hooks
- How to write reusable React Hooks
- Common React Hooks mistakes to avoid in your code
- Transpilers and bundlers for JavaScript libraries
- Using GitHub Actions to test, build, and lint your library
- Publish your React Hooks library to NPM

We’ll use tools including React, TypeScript, Babel, as well as GitHub Actions to build, test, and package a React Hooks library available for others to download from NPM.  Ultimately, build your own React Hooks library and learn the best practices that will make your code reusable. With these skills, you can contribute more confidently to any React codebase using React Hooks, and make your team more productive.

This course is a complete step-by-step guide to coding custom React Hooks and building a Hooks library from scratch.  Confidently master React Hooks, a transformative update added since React version 16.8, that makes it much easier to reuse code as your React codebase grows.

The newline Guide to Creating a React Hooks Library

Common React Hooks mistakes to avoid in your code

Transpilers and bundlers for JavaScript libraries

Using GitHub Actions to test, build, and lint your library

Custom plugins enable users to extend the base official functionality of Babel - for transpilers this means some pluggable transforms. So what exactly is a transform?

If you're advanced enough, you may know about 

 and how to manipulate them. This is exactly what Babel plugins do, but this topic is way too advanced and may take another course to cover in depth. So let's try to put it simply. Babel plugins are functions that simply 

take code in a format that is easy to operate on and outputs another code, based on logic provided by a developer.

, by finding their usages in the code. Why is this needed? Because with CommonJS modules, import of any function from 

 internals to the bundle. So to optimize that without affecting the code, this plugin comes in to save the day. You may argue, - "But isn't it will be handled automatically? Lodash is mega popular, isn't it not comes in ES Modules format that handles it all automatically?". And you will be right, about your assumption, as most of the libraries do support both CJS and ESM, but not 

 in ES Modules format, you need to install and import 

 package. Why it's two different packages? I have no idea, but this is how it is. Either way hopefully these particular optimizations will soon be obsolete as Parcel, Webpack and Rollup have all introduced CommonJS tree-shaking functionality in their latest versions.

Shall we do another example of the plugin?
There is also a 

 which make some dynamic code static if it's possible to predict. A good example would be 

 functions, which lighten or darken original color by a percentage. So code like:

---
title: "What are Babel Transforms and Plugins?"
slug: transforms-and-plugins
isPublicLesson: false
---

Custom plugins enable users to extend the base official functionality of Babel - for transpilers this means some pluggable transforms. So what exactly is a transform?

If you're advanced enough, you may know about **abstract syntax trees (ASTs)** and how to manipulate them. This is exactly what Babel plugins do, but this topic is way too advanced and may take another course to cover in depth. So let's try to put it simply. Babel plugins are functions that simply _take code in a format that is easy to operate on and outputs another code, based on logic provided by a developer._

Let's look at an example, starting with `babel-plugin-lodash`, which changes wildcard imports like `import _ from 'lodash'` or `import { map, merge } from 'lodash'` to make them more precise, for example `import map from 'lodash/map'` and `import merge from 'lodash/merge'`, by finding their usages in the code. Why is this needed? Because with CommonJS modules, import of any function from `lodash` directly takes _all_ `lodash` internals to the bundle. So to optimize that without affecting the code, this plugin comes in to save the day. You may argue, - "But isn't it will be handled automatically? Lodash is mega popular, isn't it not comes in ES Modules format that handles it all automatically?". And you will be right, about your assumption, as most of the libraries do support both CJS and ESM, but not `lodash`, to have `lodash` in ES Modules format, you need to install and import `lodash-es` package. Why it's two different packages? I have no idea, but this is how it is. Either way hopefully these particular optimizations will soon be obsolete as Parcel, Webpack and Rollup have all introduced CommonJS tree-shaking functionality in their latest versions.