Chris Seckler zeckdude

Array Iteration

https://gist.github.com/ljharb/58faf1cfcb4e6808f74aae4ef7944cff

While attempting to explain JavaScript's reduce method on arrays, conceptually, I came up with the following - hopefully it's helpful; happy to tweak it if anyone has suggestions.

Intro

JavaScript Arrays have lots of built in methods on their prototype. Some of them mutate - ie, they change the underlying array in-place. Luckily, most of them do not - they instead return an entirely distinct array. Since arrays are conceptually a contiguous list of items, it helps code clarity and maintainability a lot to be able to operate on them in a "functional" way. (I'll also insist on referring to an array as a "list" - although in some languages, List is a native data type, in JS and this post, I'm referring to the concept. Everywhere I use the word "list" you can assume I'm talking about a JS Array) This means, to perform a single operation on the list as a whole ("atomically"), and to return a new list - thus making it mu

Option 1: Command-line download extension as zip and extract

extension_id=jifpbeccnghkjeaalbbjmodiffmgedin   # change this ID
curl -L -o "$extension_id.zip" "https://clients2.google.com/service/update2/crx?response=redirect&os=mac&arch=x86-64&nacl_arch=x86-64&prod=chromecrx&prodchannel=stable&prodversion=44.0.2403.130&x=id%3D$extension_id%26uc" 
unzip -d "$extension_id-source" "$extension_id.zip"

Thx to crxviewer for the magic download URL.

The Ultimate Unit Testing Cheat-sheet

Sinon Chai
Chai
Sinon

	import React from 'react';

	const ConditionalWrap = ({condition, wrap, children}) => condition ? wrap(children) : children;

	const Header = ({shouldLinkToHome}) => (
	<div>
	<ConditionalWrap
	condition={shouldLinkToHome}
	wrap={children => <a href="/">{children}</a>}
	>

	import React from 'react';

	const ConditionalWrap = ({condition, wrap, children}) => condition ? wrap(children) : children;

	const Header = ({shouldLinkToHome}) => (
	<div>
	<ConditionalWrap
	condition={shouldLinkToHome}
	wrap={children => <a href="/">{children}</a>}
	>

	// returns an array of localStorage items in key/value pairs based on a query parameter
	// returns all localStorage items if query isn't specified
	// query can be a string or a RegExp object

	function findLocalItems (query) {
	var i, results = [];
	for (i in localStorage) {
	if (localStorage.hasOwnProperty(i)) {
	if (i.match(query) \|\| (!query && typeof i === 'string')) {
	value = JSON.parse(localStorage.getItem(i));