Welcome to the Guide to Building a Company Component Library course.

Course Welcome

The different types of component libraries and their uses.

An Intro to Component Libraries and Design Systems

Syllabus

How to setup your environment to complete this course.

Environment setup

Introduction

Which React Components to Build? An Atomic Design Guide

Which UI Elements Should be Turned Into React Components?

Choose React Dependencies for a Maintainable Component Library

Shared components

How to Host an NPM Package in GitHub for Free

How to Add Storybook to React to Test Component Library Locally

How to Keep React Code Consistent With Prettier and ESLint

Library creation

Build a Custom React Button Component With forwardRef API

Build a Custom Design System With React Styled Components

Validate React Props With PropTypes and TypeScript

Shared component patterns

How to Design Compound Components With React Context

How to Design Custom React Field Components With useUniqueID

How to Extend Styled Component Styles With New Style Props

Advanced patterns

How to Test React Component Libraries With ts-jest

How to Build Tests For React Button Components

How to Build Accessibility Tests For React Field Components

Component testing

The Best Ways to Bundle React Modules Into Packages

Build process

Setting Up Continuous Integration for a React Component Library With GitHub Actions

Deployment and automation

This course will teach you how to create a flexible, private, enterprise-grade component library using React.

Since its introduction in 2013, React has become one of the [most used front-end frameworks](https://2019.stateofjs.com/front-end-frameworks/). Its component-based architecture and flexibility has made it the framework of choice for those needing to share code across multiple teams.

However, the same flexibility that has helped React grow in popularity also creates many challenges when creating shared assets and tooling. Some of the most commonly asked questions include:

- What components should be shared?
- How do I choose which dependencies to include in my library?
- Which component APIs and design patterns allow for the most flexibility?
- How do I document and build my components?
- How should I be testing my library?
- Where do I deploy my components for internal use?

This course will teach you how to create a flexible, private, enterprise-grade
component library using React.

The newline Guide to Building a Company Component Library

How to identify potential shared components in an existing codebase

Importance of choosing your libraries dependencies

How to create an NPM library from scratch with TypeScript and Storybook

Basic and advanced API patterns for shared components

How to build and deploy a modern NPM package to a private NPM registry

 we will be testing each compound component to ensure that it applies the correct accessibility attributes.

// File: src/fields/Field.spec.tsx

import React from 'react';
import { render, screen } from '@testing-library/react';
import { Field } from './Field';

describe('Field', () => {
  describe('Label', () => {
    it('applies unique ID to htmlFor attribute', () => {});
  });

  describe('Input', () => {
    it('applies unique ID to id attribute', () => {});
  });

  describe('TextArea', () => {
    it('applies unique ID to id attribute', () => {});
  });
});

If Jest is no longer running, start it in 

 component receives a unique ID applied as a 

 attribute. If we were to implement a test now, every render of the component would create a unique result for that ID. Let's test that by adding the following:

it('applies unique ID to htmlFor attribute', () => {
  render(
    <Field>
      <Field.Label>Label</Field.Label>
    </Field>
  );

  screen.debug();
});

 is a utility that will display the current DOM structure of the rendered test. Every time we save the test you can see the unique 

 value change. To help make our tests more predictable we will be creating a 

---
title: How to Build Accessibility Tests For React Field Components
privateVideoUrl: https://fullstack.wistia.com/medias/2rcwqq36wj
---

For our `Field` we will be testing each compound component to ensure that it applies the correct accessibility attributes.

## Create `Field` tests

First we need to create `Field.spec.tsx` with the following content:

```bash
touch src/fields/Field.spec.tsx
```

```tsx
// File: src/fields/Field.spec.tsx

import React from 'react';
import { render, screen } from '@testing-library/react';
import { Field } from './Field';

describe('Field', () => {
  describe('Label', () => {
    it('applies unique ID to htmlFor attribute', () => {});
  });

  describe('Input', () => {
    it('applies unique ID to id attribute', () => {});
  });

  describe('TextArea', () => {
    it('applies unique ID to id attribute', () => {});
  });
});
```

If Jest is no longer running, start it in `--watch` mode.

```bash
npm run test -- --watch
```

## Mocking custom hooks

Our first test is asserting that a `Field.Label` component receives a unique ID applied as a `for` attribute. If we were to implement a test now, every render of the component would create a unique result for that ID. Let's test that by adding the following:

```tsx
it('applies unique ID to htmlFor attribute', () => {
  render(
    <Field>
      <Field.Label>Label</Field.Label>
    </Field>
  );

  screen.debug();
});
```

`screen.debug()` is a utility that will display the current DOM structure of the rendered test. Every time we save the test you can see the unique `for` value change. To help make our tests more predictable we will be creating a [manual mock](https://jestjs.io/docs/manual-mocks) for the `useUniqueID` utility.

How to Build Accessibility Tests For React Field Components

Masterclasses

Tutorials

Fullstack React with TypeScript