Learn A11y, Firebase and Particle

Web accessibility (also referred to as a11y) is the design and creation of websites that can be used by everyone. Accessibility support is necessary to allow assistive technology to interpret web pages.

React fully supports building accessible websites, often by using standard HTML techniques.

Erin Doyle is an expert in creating accessible React applications and has developed a course that will give you a concrete process for auditing react apps for accessibility. In this course, you will go through different tools and libraries to audit components in a React app.

Fast, easy and reliable testing for anything that runs in a browser.

cypress

Auditing React Apps for Accessibility 

Protect yourself from unexpected charges by learning how to use Firebase emulators. 

By using Firebase emulators you no longer have to create a second dev firebase project to avoid using production data. You also don't run the risk of having a cloud function crash and run up a huge bill.

In this course, you'll learn how to set up and use Firebase's authentication, function, and Firestore emulators. You will also learn how to safely set up Cloud Function emulation, import seed data into your emulators, and disable the emulators in production.  

By the end of this course, you'll be able to confidently set up a safe environment for testing in your own applications!

firebase

Local App Development with the Firebase Emulator Suite

AngularJS is an open-source JavaScript framework, maintained by Google, that assists with running single-page applications. Its goal is to augment web-based applications with model–view–controller (MVC) capability, in an effort to make both development and testing easier.

angularjs

The Firebase Forge provides a convenient GUI for visualizing and manipulating your data in real-time. Be sure to check out [this lesson](https://egghead.io/lessons/angularjs-get-started-with-firebase-and-angularfire) for getting Firebase setup.

Updating Real-Time Data with Firebase Forge

When using Firebase collections in your AngularJS application, you have access to a handy set of events emitted by the collection when changes in your data occur. Be sure to check out the [first lesson](https://egghead.io/lessons/angularjs-get-started-with-firebase-and-angularfire) in this series for the project source code.

Firebase Event Handling

Firebase provides a real-time syncing backend for your AngularJS applications in very few lines of code. In this lesson, you'll learn how to get started integrating it into your app.

Get Started with Firebase and AngularFire

Data has relationships, and Firebase allows you to define those relationships in your AngularJS applications.

Firebase Data Relationships

Firebase has several ways to provide authentication for your AngularJS application. In this lesson, Lukas will look at the most basic email/password approach.

Firebase Basic Authentication Part 1

React is one of the web’s most popular frameworks for building JavaScript applications. 

If you know what you’re doing, React can drastically simplify how you build, use, and maintain code.

Whether you’re a React newbie or you’re ready for advanced techniques, you can level-up with egghead. Explore our in-depth courses, lessons, and community resources to build more powerful applications and crack open your career.

react

React becomes incredibly powerful when coupled with a real-time backend like Firebase. See how easy it is to bring the two together and chat with Star Wars characters while you're at it.

React and Firebase with ReactFire

Authenticating with Firebase creates a 24 hour session for the user. This allows you to fetch the current session for the user, as well as logout the user and destroy the session.

Firebase Basic Authentication Part 2

particle

Before powering up the Particle Photon we are going to look at what each of the components are on the board.

Particle Photon Component Overview

🔥 Firebase provides several easy-to-use authentication methods that we can use to handle auth in React apps. 

In this lesson, we will cover how to authenticate a user via an email and password. This is done using `createUserWithEmailAndPassword` function available to us from the `firebase` library. 

You'll need firebase configured in your application which you can [read about here.](https://dev.to/farazamiruddin/react-firebase-add-firebase-to-a-react-app-4nc9)

Authenticate a User in React with Firebase

Building a component library is a great way to gain efficiencies in creating accessible React apps and Storybook is a great tool for doing that. Using the accessibility add-on to Storybook you can test your components in isolation for accessibility issues before composing them into an application.

If you can write and test each of these components initially with accessibility in mind then you now have:

* A library of reusable components with accessibility baked in.
* You won’t need to solve the same problems over and over again.

## Resources
* https://storybook.js.org/
* https://www.npmjs.com/package/@storybook/addon-a11y

Audit Component Accessibility Using Storybook

AngularFire is the officially supported AngularJS binding for Firebase. Firebase is a backend service that provides data storage, file storage, authentication, and static website hosting for your Angular app.

angularfire

You'll learn the 2 Observables that Firebase Authentication provides to subscribe to the authentication state of your application, `authState` and `user`.

You'll see how they both return the same `User` object from Firebase Authentication.

And you'll learn that the difference is that `authState` triggers when the user logs in, or logs out of the application, while `user` is called both of those times, and also is called when Firebase refreshes the user's authentication token.

As a personal guideline, if I need to do an operation when the user's token is refreshed (_for example, update a 3rd party service_) I'll use `user`, if not, I'll default to `authState`.

Choose Between authState or user to Subscribe to Firebase Authentication State Changes

We can add accessibility testing to our `jest` unit tests with `jest-axe` which gives us:

* An easy way to automate accessibility auditing.
* The flexibility to audit at any level of our code, as low as an element and as high as a component representing an entire page of our app.
* A safety net for any accessibility regressions.

Here we'll see how to use `jest-axe` with `ReactDOM` to render components for `jest-axe` to audit for accessibility.

## Resources
* https://github.com/nickcolley/jest-axe

Render Components with ReactDOM to Write Tests with Jest and jest-axe

“a11y” stands for “accessibility.” It is a numeronym, with 11 representing the count of letters between the letter a and the letter y.

Accessibility is broken down into 4 categories of disability: visual, cognitive, auditory, motor. 

Regardless of the category of disability, accessibilities aim in web development is to make applications and websites usable for everyone.

a11y

To automate running Lighthouse audits on our application we can add the use of the Lighthouse CI tool to our Continuous Integration suite using GitHub Actions.  By making use of the Lighthouse CI GitHub App we can add to the checks in every Pull Request a report with the score from the audit run on each URL we configure for Lighthouse to audit.

## Resources
* https://github.com/GoogleChrome/lighthouse-ci/blob/main/docs/getting-started.md
* https://github.com/GoogleChrome/lighthouse-ci/blob/main/docs/configuration.md
* https://github.com/apps/lighthouse-ci

Automate Lighthouse Audits with GitHub Actions

JavaScript® (often shortened to JS) is a lightweight, interpreted, object-oriented language with first-class functions, most known as the scripting language for Web pages, but used in many non-browser environments as well such as node.js or Apache CouchDB. It is a prototype-based, multi-paradigm scripting language that is dynamic, and supports object-oriented, imperative, and functional programming styles.

javascript

You’ve probably heard of Lighthouse before as it comes bundled with Chrome DevTools for performing a number of audits on things such as performance, SEO, best practices as well as accessibility. 

We can also use Lighthouse locally on our machines to test our application's rendered pages for accessibility issues before committing changes by using the Lighthouse CI CLI.

## Resources
* https://github.com/GoogleChrome/lighthouse-ci
* https://github.com/GoogleChrome/lighthouse-ci/blob/main/docs/configuration.md

Audit an App's Rendered Pages Locally with Lighthouse CI CLI

The pluggable linting utility for JavaScript and JSX.

eslint

We can leverage GitHub Actions to automate the running of all of our accessibility auditing tools as part of a Continuous Integration (CI) workflow. 

Auditing tools will only catch a percentage of potential accessibility issues, it is no replacement for manual testing.  But being able to automate the auditing will add efficiencies to our testing and provide an early warning system that can be run much more frequently than it’s practical to perform manual testing.  Additionally, we can use our CI suite as a safety net to prevent code changes that break accessibility from being able to be merged.

## Resources
* https://app.egghead.io/lessons/react-set-up-eslint-to-audit-accessibility-issues-in-react
* https://docs.cypress.io/guides/continuous-integration/github-actions#Basic-Setup
* https://github.com/cypress-io/github-action

Automate Accessibility Audits with GitHub Actions

To audit our app for accessibility issues at runtime we can use Cypress to run our application in a browser environment and then with the aid of the axe-core `cypress-axe` library we can analyze the current page for any accessibility issues.

## Resources
* https://www.cypress.io/
* https://github.com/component-driven/cypress-axe
* https://mochajs.org/#bdd
* https://www.chaijs.com/guide/styles/

Write E2E Tests for Accessibility Using aXe-core and Cypress

To audit our app for accessibility issues at runtime we can use Selenium WebDriver to run our application in a browser environment and then with the aid of the aXe-core `webdriverjs` library we can analyze the current page for any accessibility issues.

## Resources
* https://www.selenium.dev/documentation/getting_started/installing_browser_drivers/
* https://github.com/dequelabs/axe-core-npm/blob/develop/packages/webdriverjs/README.md 

Test Accessibility at Runtime with Selenium WebDriver and aXe-Core

We can add accessibility testing to our `jest` unit tests with `jest-axe` which gives us:

* An easy way to automate accessibility auditing.
* The flexibility to audit at any level of our code, as low as an element and as high as a component representing an entire page of our app.
* A safety net for any accessibility regressions.

Here we'll see how to use `jest-axe` with `enzyme` to render the components for `jest-axe` to audit for accessibility.

Enzyme is a JavaScript Testing utility for React that makes it easier to test your React Components' output. You can also manipulate, traverse, and in some ways simulate runtime given the output.

## Resources
* jest-axe: https://github.com/nickcolley/jest-axe
* enzyme: https://enzymejs.github.io/enzyme

Write Unit Tests for Accessibility Using jest-axe and enzyme

We can add accessibility testing to our `jest` unit tests with `jest-axe` which gives us:

* An easy way to automate accessibility auditing
* the flexibility to audit at any level of our code, as low as an element and as high as a component representing an entire page of our app
* A safety net for any accessibility regressions

Here we'll see how to use `jest-axe` with `react-testing-library` to render the components for `jest-axe` to audit for accessibility.

The React Testing Library is a very light-weight solution for testing React components. It provides light utility functions on top of react-dom and react-dom/test-utils, in a way that encourages better testing practices.

## Resources
* jest-axe: https://github.com/nickcolley/jest-axe
* react-testing-library: https://testing-library.com/docs/react-testing-library/intro/