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Andrea Giammarchi WebReflection

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View hooks-in-a-nutshell.js
// WARNING: There's much more to know/do around hooks, and
// this is just a simplification of how these work.
// shared references, updated
// per each hook invoke
let execution = null;
let current = null;
let context = null;
let args = null;
View if-then-else-if-else.js
const If = expression => {
let call = true, value;
return {
then: callback => Promise.resolve(value).then(callback),
Then(callback) {
if (call && expression) {
call = false;
value = callback(expression);
return this;
View async-tag.js
const {isArray} = Array;
const sync = async values => {
for (let {length} = values, i = 0; i < length; i++) {
const value = await values[i];
values[i] = isArray(value) ? await sync(value) : value;
return values;

Toward better libraries

I am recently re-branding my libraries as µ (micro), refactoring these when necessary, dropping IE < 11 support, improving the logic where possible, or providing a better, more robust, or faster, API.

In few words, on the right there is the modern version of libraries I've used for the last ~5 years in production or for side projects, and I suggest anyone having one of the earlier dependencies, to have a look at their modern, micro, counterpart.

How to read these tables

All sizes are minified, brotli compressed, and representing these two files, when possible:

View use-state-caller.js
function useState(value) {
const {caller} = arguments.callee;
const {arguments: a} = caller;
const {stack} = useState;
if (!stack.has(caller))
stack.set(caller, {a, i: 0, s: []});
const state = stack.get(caller);
state.a = a;
const {i, s} = state;
if (i === s.length) {
WebReflection /
Last active Dec 1, 2020
A privileged answer to a well known issue.

This site throws in users and, most importantly, developers face, the fact publishing websites with hundreds of JS Kilobytes just to see some content, content that might also break due JS itself or browsers that haven't been tested or targeted, is very bad.

The same site is also great to remind everyone that a11y (accessibility) matters, and if you got upset by its disruptive technique, and you are a Web developer, now you know how it feels for people incapable of surfing the "modern Web" with its overly-bloated frameworks and practices that way too often don't take a11y into account.

However, JS is not to blame here, while developers abusing JS without following graceful enhancement practices, or without testing their sites offer some meaningful content even for users that might have disabled JS for whatever reason, are to blame so ... please "don't be that kind of developer".

That being said, as an exercise to see if I could surf it via JS, I've created this ti

View lru-map.js
// Least Recently Used
class LRUMap extends Map {
constructor(length) {
super().length = length;
_(key) {
const value = super.get(key);
super.set(key, value);
return value;
WebReflection / attr.js
Created Nov 19, 2020
A dataset like behavior for any attribute
View attr.js
const proxies = new WeakMap;
const hyphen = name => name.replace(/([a-z])([A-Z])/g, '$1-$2');
const handler = {
get: (el, name) => el.getAttribute(hyphen(name)),
set: (el, name, value) => {
el.setAttribute(hyphen(name), value);
return true;
const set = el => {
WebReflection / wm-inheritance.js
Last active Nov 17, 2020
WeakMap VS root classes
View wm-inheritance.js
WeakMap.prototype.hasInherited = function hasInherited(obj) {
let found = false;
while (obj && obj !== Object.prototype && !(found = this.has(obj)))
obj = Object.getPrototypeOf(obj);
return found;
WeakMap.prototype.setInherited = function setInherited(obj, value) {
let ref = obj;
while (ref && ref !== Object.prototype) {

async / return await explained

This is yet another explanation of why async and return await is pointless, coming from this post.

// async means that this:
const fn = async (...args) => {/* stuff */};

// is basically the equivalent of this: