sindresorhus

Gettings started writing a ESLint rule

First, take a look at the ESLint rule documentation. Just skim it for now. It's very long and boring. You can come back to it later.

ESLint rules works on the AST (Abstract Syntax Tree) representation of the code. In short, this is a tree structure that describes the code in a very verbose form. ESLint walks this tree and rules can subscribe to be notified when it hits a specific node type, like a Literal type, which could be the "hello" part of const welcome = "hello";.

Go ahead and play around with some code in AST Explorer (Make sure the parser is espree). It's a great tool!

Here are some good articles on the subject (ignore the scaffolding parts):

• https://insideops.wordpress.com/2015/12/08/creating-custom-rules-for-eslint/

gaearon

Note:

When this guide is more complete, the plan is to move it into Prepack documentation.
For now I put it out as a gist to gather initial feedback.

A Gentle Introduction to Prepack (Part 1)

If you're building JavaScript apps, you might already be familiar with some tools that compile JavaScript code to equivalent JavaScript code:

• Babel lets you use newer JavaScript language features, and outputs equivalent code that targets older JavaScript engines.

kentcdodds

// create a React context Provider/Consumer pair that
// validates the consumer is rendered within a provider
function createRequiredContext(name) {
  const Context = React.createContext()

  function Consumer(props) {
    return (
      <Context.Consumer {...props}>
        {val => {
          if (!val) {

dsandif

Tutorial

This is a tutorial on hosting a static website on Amazon S3 and Cloudfront. I made this based on an Angular 6 frontend but this write up can also be used as a guide for other frameworks like React or Vue.js. This tutorial also assumes that you already have an Amazon AWS account and domain name through Google Domains or Amazon Route 53. I use Google Domains as a registrar but I will also cover using Amazon Route 53.

Hosting a static SPA on AWS is a pretty straightforward process. This guide will cover:

• Creating and configuring an S3 bucket for a Single-Page Application (SPA)
• Uploading an application to an Amazon S3 bucket
• Creating and configuring a Cloudfront Distribution
• Configuring Google Domains OR Amazon Route 53

samsch

Stop using JWTs!

TLDR: JWTs should not be used for keeping your user logged in. They are not designed for this purpose, they are not secure, and there is a much better tool which is designed for it: regular cookie sessions.

If you've got a bit of time to watch a presentation on it, I highly recommend this talk: https://www.youtube.com/watch?v=pYeekwv3vC4 (Note that other topics are largely skimmed over, such as CSRF protection. You should learn about other topics from other sources. Also note that "valid" usecases for JWTs at the end of the video can also be easily handled by other, better, and more secure tools. Specifically, PASETO.)

A related topic: Don't use localStorage (or sessionStorage) for authentication credentials, including JWT tokens: https://www.rdegges.com/2018/please-stop-using-local-storage/

The reason to avoid JWTs comes down to a couple different points:

• The JWT specification is specifically designed only for very short-live tokens (~5 minute or less). Sessions