jordienr

// Remember to install mini-svg-data-uri
// Follow me on twitter for memes @jordienr

import { type Config } from "tailwindcss";
const {
  default: flattenColorPalette,
} = require("tailwindcss/lib/util/flattenColorPalette");
const svgToDataUri = require("mini-svg-data-uri");

export default {

ClickerMonkey

// when T is any|unknown, Y is returned, otherwise N
type IsAnyUnknown<T, Y, N> = unknown extends T ? Y : N;
  
// when T is never, Y is returned, otherwise N
type IsNever<T, Y = true, N = false> = [T] extends [never] ? Y : N;

// when T is a tuple, Y is returned, otherwise N
// valid tuples = [string], [string, boolean], 
// invalid tuples = [], string[], (string | number)[]

busypeoples

// TypeScript Fundamentals For JavaScript Developers

/*
  Tutorial for JavaScript Developers wanting to get started with TypeScript.
  Thorough walkthrough of all the basic features.
  We will go through the basic features to gain a better understanding of the fundamentals.
  You can uncomment the features one by one and work through this tutorial.
  If you have any questions or feedback please connect via Twitter:
  A. Sharif : https://twitter.com/sharifsbeat
*/

sebmarkbage

The Rules of React

All libraries have subtle rules that you have to follow for them to work well. Often these are implied and undocumented rules that you have to learn as you go. This is an attempt to document the rules of React renders. Ideally a type system could enforce it.

What Functions Are "Pure"?

A number of methods in React are assumed to be "pure".

On classes that's the constructor, getDerivedStateFromProps, shouldComponentUpdate and render.

jaredpalmer

import React from 'react';
import debounce from 'utils/debounce';

class EmailInput extends React.Component {
  checkEmail = value => {
    // only check if the field passes Yup email validation first
    if (
      !this.props.form.errors[this.props.name].includes(
        'invalid' /* or whatever your error message is*/
      )

developit

state-machine-component

A tiny (265 byte) utility to create state machine components using two pure functions.

🔥 JSFiddle Demo

Usage

The API is a single function that accepts 2 pure functions as arguments:

busypeoples

import {
  ifElse,
  map,
  partial,
} from 'ramda'

const isObject = input => typeof input === 'object'

/**
 * Like map but for deeply nested objects

mattpodwysocki

'use strict';

let arr = [1,2,3,4,5];
let fn = (acc, x) => {
   console.log(`${acc}-${x}`); 
   return acc * x;
};
let seed = 1;

/*

DaBs

var str = 'class ಠ_ಠ extends Array {constructor(j = "a", ...c) {const q = (({u: e}) => {return { [`s${c}`]: Symbol(j) };})({});super(j, q, ...c);}}' + 
          'new Promise((f) => {const a = function* (){return "\u{20BB7}".match(/./u)[0].length === 2 || true;};for (let vre of a()) {' +
          'const [uw, as, he, re] = [new Set(), new WeakSet(), new Map(), new WeakMap()];break;}f(new Proxy({}, {get: (han, h) => h in han ? han[h] ' + 
          ': "42".repeat(0o10)}));}).then(bi => new ಠ_ಠ(bi.rd));';

try {
  eval(str);
} catch(e) {
  alert('Your browser does not support ES6!')
}

markerikson

Cheng Lou - On the Spectrum of Abstraction

Cheng Lou, a former member of the React team, gave an incredible talk at React Europe 2016 entitled "On the Spectrum of Abstraction". That talk is available for viewing here: https://www.youtube.com/watch?v=mVVNJKv9esE

It's only a half-hour, but it is mind-blowing. It's worth re-watching two or three times, to let the ideas sink in.

I just rewatched the talk for some research, and wrote down a summary that's semi-transcript-ish. I didn't see any other transcripts for this talk, other than the auto-generated closed captions, so I wanted to share for reference.

Summary