Jack Herrington jherr

Frameworks like React require that when you change the contents of an array or object you change its reference. Or push another way that you don't change arrays but instead create new arrays with updated values (i.e. immutability).

There are older array methods that are incompatible with immutability because they alter the array in place and don't change the array reference. These are mutable (or destructive) methods.

Shown below are replacements for the array destructive methods (e.g. push, pop, splice, sort, etc.) that will create new array references with the updated data.

Solutions are provided using the spread operator and also the newer "change array by copy" methods (toSpliced, toSorted, toReversed and with).

Setting Value At Index

VS Code setup

Settings are listed in settings.json
Editor Font: Operator Mono
Terminal Font: SpaceMono NF

Significant Extensions

Original article

First create the NX workspace and the initial application named search:

npx create-nx-workspace@latest ang-pokemon-mfe

Set it up as angular, with the name search and SCSS for the styling:

	{
	"$schema": "https://raw.githubusercontent.com/JanDeDobbeleer/oh-my-posh/main/themes/schema.json",
	"palettes": {
	"template": "bcc",
	"list": {
	"bcc": {
	"base": "#0F9BF2",
	"color-2": "#10b1d5",
	"color-3": "#38939d",
	"color-4": "#503FBF",

	{
	"$schema": "https://raw.githubusercontent.com/JanDeDobbeleer/oh-my-posh/main/themes/schema.json",
	"palettes": {
	"template": "bcc",
	"list": {
	"bcc": {
	"base": "#0F9BF2",
	"color-2": "#10b1d5",
	"color-3": "#38939d",
	"color-4": "#503FBF",

	{
	"root": true,
	"env": {
	"browser": true,
	"es6": true,
	"node": true
	},
	"extends": [
	"standard",
	"plugin:no-unsanitized/DOM",

	export function runify(obj) {
	if(Array.isArray(obj)) {
	return obj.map(runify);
	} else if(typeof obj === 'object') {
	let rune = $state(obj);
	let output = {};
	for(let key in rune) {
	if(typeof obj[key] === 'object') {
	obj[key] = runify(obj[key]);
	}

	/*
	There is currently no way to get a `.astro` route to just return the HTML
	without the CSS and JS. This is a workaround to remove the CSS and JS from
	the HTML response of HTMX fragment routes.

	The premise here is that HTMX fragments won't required additional styles because
	the Tailwind for the entire experience is alreay precomputed. And second that it will
	not require additional JS because ... HTMX.
	*/
	const HTMX_FRAGMENT_ROUTES = ["/prompt"];

	const numberFormat = new Intl.NumberFormat("en-US", { style: "decimal" });

	const TEST_ARRAY_SIZE = 1000;
	const TEST_COUNT = 1000;

	const pushUsingPush = (arr) => {
	arr.push(5);
	return arr;
	};

	{
	"name": "packages",
	"version": "1.0.0",
	"main": "index.js",
	"license": "MIT",
	"private": true,
	"scripts": {
	"start": "concurrently \"wsrun --parallel start\""
	},
	"workspaces": [