Learn Egghead, Eslint and Mocha

This is the video companion to the [egghead.io Instructor Guide](https://howtoegghead.com/instructor/).

Screencasting is hard! There are virtually infinite ways to produce one. For an egghead.io lesson we expect several key aspects to be met. We want to make sure that our lessons have depth and clarity. Clarity is important and starts with the technical aspects of recording your screen and voice. Once we have achieved this objective level of clarity, we dip into the stylistic aspects of recording a lesson. The style is subjective, and the goal of an egghead.io lesson is not to have an army of uniform drone producing flavorless video content for the masses.

Our mission is to make you a badass screencaster. We want to push you to another level. We've found that a small set of standard practices will create an awesome experience for the student, and eliminate frustration as we teach by providing a repeatable pattern for success. It’s not complicated. In fact, it is simple, but it isn’t easy.


This course will show you how to produce an egghead.io lesson. We strive for consistency in style, and these lessons will demonstrate the core elements that create our brand screencasts. Let’s learn how together.

Bite-size video tutorials for badass web developers.

egghead

Record Badass Screencasts for egghead.io

Miscellaneous one-off lessons on debugging, productivity hacks, and JavaScript tricks.

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

Tips and Tricks

The Chrome Developer Tools (DevTools for short), are a set of web authoring and debugging tools built into Google Chrome.

chrome-devtools

Your page is showing high CPU usage and spinning up your laptop fan, but nothing is visibly happening. What is it doing, and why is it so slow?

This lesson is a real-world performance diagnosis of this very page, right here on egghead. Two infinite (but hidden) animations were causing CPU usage to spike, and Chrome's Task Manager and Performance tools helped uncover the elements causing the problem. You'll see how to use the profiler to record a snapshot, and learn a trick for discovering animations running in the background.

Diagnose a Slow Page Using Developer Tools

codesandbox.io provides one of the fastest ways to start a new React project. In this lesson, we will take a first look at codesandbox, its interface, and the default React project it creates.

Use Codesandbox to Start a New React Application

By re-assigning a couple mouse buttons, you can drastically improve the speed you can edit your lessons in Screenflow. This lesson shows how to customize using the Logitech software, but the concept should work for any mouse customization software as well.

Faster Edits in Screenflow with Mouse Customizations

Sometimes you have an idea that you want to quickly record, but the idea of setting up a project just to get it recorded gets in your way. I'm going to walk your through scripting away the main setup pain points so that you can focus on creating content.

Automate egghead Lesson Setup with ZSH Shell Functions

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

Our first layer of defense when building accessible React applications is to add some auditing tools to our development workflow. This should include adding static analysis checking for common accessibility standards and best practices. We can get this with the latest eslint plugin: "eslint-plugin-jsx-a11y". If you are already linting your projects adding this plugin should fit very smoothly into your workflow.

## Resources
1. [List of all the rules supported by eslint-plugin-jsx-a11y](https://github.com/evcohen/eslint-plugin-jsx-a11y#supported-rules)
2. [Comparison of the difference in rules between recommended and strict mode](https://github.com/evcohen/eslint-plugin-jsx-a11y#difference-between-recommended-and-strict-mode)
3. [Background on how the Accessibility API implemented by browsers interfaces with Assistive Technologies](https://github.com/evcohen/eslint-plugin-jsx-a11y#some-background-on-wai-aria-the-ax-tree-and-browsers)

Set up ESLint to Audit Accessibility Issues in React

When making your font sizes large, your code will often get to long to fit on the screen. This lesson shows you how to use "word wrap" or "prettier print width" to adjust your code to fit within the editor.

Reformat Code to Fit the Screen

The pluggable linting utility for JavaScript and JSX.

eslint

We have a number of options to use when testing for accessibility issues concerning alternative text for images.  The react-axe library and axe browser extension will both report when an image is missing alternative text.  The tota11y browser extension will annotate any images that are missing alternative text.  Running eslint with the eslint-plugin-jsx-a11y plugin installed will report on any `<img>` elements missing an `alt` attribute.  Finally, we can use a screen reader to actually hear what is read when an image has focus.

Test for Image Alternative Text Accessibility Issues

Images must have text alternatives that describe the information or function 
represented by them so they can be read and understood by those using screen readers.

## Alternative text for images
* All `<img>` elements should have an `alt` attribute provided
    * When not provided many screen readers will fallback to reading the file name instead
* The `alt` value should not include words like _“image”_, _“picture”_ or _“icon”_
    * Screen readers are already announcing that the element is an image
* Images that are decorative only and provide no information or function to the page should be hidden from Assistive Technologies by providing an empty `alt` attribute (`alt=””`)

## References
* https://www.w3.org/WAI/tutorials/images/
* https://www.w3.org/WAI/tutorials/images/decision-tree/
* https://www.w3.org/WAI/tutorials/images/tips/
* https://www.w3.org/WAI/tutorials/images/informative/
* https://www.w3.org/WAI/tutorials/images/functional/
* https://www.w3.org/WAI/tutorials/images/textual/

Define Images with Appropriate Text Alternatives

Our accessibility auditing toolkit makes it very easy for us to test for any form controls that are missing labels or are not correctly associated with their labels.  Running Eslint with the eslint-plugin-jsx-a11y installed will show us any form controls with missing or unassociated labels.  Running react-axe or using axe to audit a web page will similarly list any of these findings.  Finally using tota11y we can annotate any form controls on a page that are missing labels.  This is definitely some of the lower hanging fruit that we can easily find and fix when making our applications accessible!

Test for Form Control Label Accessibility Issues

Labeling inputs, elements, and widgets add context and clarity for assistive technology such as screen readers.  Elements of a `<form>` such as `<input>` or `<textarea>` or `<select>` should be labelled by using a `<label>` element.  Placeholder text can be used in addition to a label but should not be used in place of a label as not all assistive technologies respect placeholder text.

Ensure Form Controls have Accessible Labels

Visual Studio Code is an integrated development environment (IDE) built and maintained by Microsoft. It is offered free of charge.

vscode

In this lesson, we will learn how to use custom ENV variables to customize the PS1 Bash/Zsh command prompt in the VS Code terminal, without affecting our custom terminal themes in other applications. We will see how this can be useful for keeping the terminal clean for screen recordings.

I'm using Zsh in this video, but this works in Bash with `~/.bashrc` as well.

Customize the PS1 Bash/Zsh Command Prompt in VS Code with Environment Variables

Lessons often have common starting points. If you're going to make lessons in bulk, it helps to create templates so you don't waste time setting them up over and over.

Create a Lesson Template

Once your lesson template is ready, it's time to create some github repos to share your code. The easiest way to do this is with Github's CLI tool called "hub".

Create Repos on Github from the CLI with hub

ZSH allows you to write functions to wrap around common commands. These allow you to easiest invoke a number of lesson creation steps by only typing out the command.

Automate Lesson Creation From Templates With ZSH Functions

Forgetting to pass an argument to a zsh function could result in creating unnecessary folders or cloning code you didn't mean to. It's best to check for arguments to prevent unwanted results.

Add Conditions to ZSH Functions to Prevent Mistakes

Once you've finished your demo locally, it's time to commit, push it to github, and share your demo online. This zsh function breaks it down into a single call.

Branch and Create a Lesson in a Single ZSH Function

Alfred is a super speed booster when it comes to common tasks. If you're going to be creating a lot of lessons from templates, Alfred can save you from even opening your terminal.

Select a Lesson Template From an Alfred Workflow

Using Alfred, you can map a global keyboard shortcut to the process of cloning a lesson template repo and firing up your demo.

Launch a New Lesson From a Keyboard Shortcut

Ripple Delete is the most common command you will perform when editing with Screenflow, thus we should make it the simplest action to perform. Unfortunately, it requires a mouse click + shift and a command + delete. We can bind this sequence to a right mouse click using Karabiner mappings.

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