DavidWells

/* Using a JavaScript proxy for a super low code REST client */
// via https://dev.to/dipsaus9/javascript-lets-create-aproxy-19hg
// also see https://towardsdatascience.com/why-to-use-javascript-proxy-5cdc69d943e3
// also see https://github.com/fastify/manifetch
// also see https://github.com/flash-oss/allserver
// and https://gist.github.com/v1vendi/75d5e5dad7a2d1ef3fcb48234e4528cb

const createApi = (url) => {
  return new Proxy({}, {
    get(target, key) {

yelouafi

Algebraic Effects in JavaScript part 1 - continuations and control transfer

This is the first post of a series about Algebraic Effects and Handlers.

There are 2 ways to approach this topic:

• Denotational: explain Algebraic Effects in terms of their meaning in mathematics/Category theory
• Operational: explain the mechanic of Algebraic Effects by showing how they operate under a chosen runtime environment

Both approaches are valuables and give different insights on the topic. However, not everyone (including me), has the prerequisites to grasp the concepts of Category theory and Abstract Algebra. On the other hand, the operational approach is accessible to a much wider audience of programmers even if it doesn't provide the full picture.

the0neWhoKnocks

Jest Testing Examples

• Common Use Cases
  • Testing a function was called with a specific Object property
  • Testing a function was called with a bound callback
  • Setting props on window.location
  • Working with History
  • Time travel
  • Testing exceptions
• Check if an Object contains multiple keys

treyhuffine

class PromiseSimple {
  constructor(executionFunction) {
    this.promiseChain = [];
    this.handleError = () => {};

    this.onResolve = this.onResolve.bind(this);
    this.onReject = this.onReject.bind(this);

    executionFunction(this.onResolve, this.onReject);
  }

hbarcelos

class BinaryTree {
    constructor(value, left=null, right=null) {
        this.value = value
        this.left = left
        this.right = right
    }
}

heyimalex

// __tests__/example.js
jest.mock('fs');

it('should serve as a nice example', () => {

  const fs = require('fs')

  // fs can be set up at any point by calling __configureFs.
  fs.__configureFs({
    '/test': {

alekseykulikov

Recently CSS has got a lot of negativity. But I would like to defend it and show, that with good naming convention CSS works pretty well.

My 3 developers team has just developed React.js application with 7668 lines of CSS (and just 2 !important). During one year of development we had 0 issues with CSS. No refactoring typos, no style leaks, no performance problems, possibly, it is the most stable part of our application.

Here are main principles we use to write CSS for modern (IE11+) browsers:

• SUIT CSS naming conventions + SUIT CSS design principles;
• PostCSS + CSSNext. Future CSS syntax like variables, nesting, and autoprefixer are good enough;
• Flexbox is awesome. No need for grid framework;
• Normalize.css, base styles and variables are solid foundation for all components;

zachbrowne

#!/bin/bash
iatest=$(expr index "$-" i)

#######################################################
# SOURCED ALIAS'S AND SCRIPTS BY zachbrowne.me
#######################################################

# Source global definitions
if [ -f /etc/bashrc ]; then
	 . /etc/bashrc

Rich-Harris

Stuff I wish I'd known sooner about service workers

I recently had several days of extremely frustrating experiences with service workers. Here are a few things I've since learned which would have made my life much easier but which isn't particularly obvious from most of the blog posts and videos I've seen.

I'll add to this list over time – suggested additions welcome in the comments or via twitter.com/rich_harris.

Use Canary for development instead of Chrome stable

Chrome 51 has some pretty wild behaviour related to console.log in service workers. Canary doesn't, and it has a load of really good service worker related stuff in devtools.

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?