JavaScript

CHALLENGE

function* generator() {
  yield 1;
  yield 2;
}

const gen = generator();
const sym = Symbol('unique');

gen[sym] = function() {
  return this.next().value;
};

console.log(gen[sym](), gen[sym](), gen[sym]());

🌲 Node.js weekly - updates

CHALLENGE

const handler = {
  get(target, prop, receiver) {
    if (prop === 'secret') {
      return Reflect.get(...arguments) + ' exposed';
    }
    return Reflect.get(...arguments);
  }
};

const secretObj = { secret: 'hidden', reveal: 'nothing' };
const proxy = new Proxy(secretObj, handler);

console.log(proxy.secret);

🌲 Node is Leaking Memory? setTimeout Could Be The Reason The folks at Sentry were running into problems with how Node handles timeouts created with setTimeout or, more specifically, problems caused by hanging on to the Timeout objects setTimeout returns.. Armin Ronacher

CHALLENGE

function* gen() {
  yield 1;
  yield 2;
  yield 3;
}

async function asyncFunc() {
  for (let value of gen()) {
    await new Promise(res => setTimeout(res, 100));
    console.log(value);
  }
  return 'done';
}

const result = asyncFunc();
console.log(result instanceof Promise);

🌲 10 Modern Node.js Runtime Features to Start Using in 2024 If it ever feels like the new feature spotlight shines too much on Bun or Deno, never fear - Node has been taking huge strides forward too. Liran helps us catch up with a lot of the newest Node features. Liran Tal

CHALLENGE

const secretKey = Symbol('key');
const secretValue = 'secret';

function Store() {
  this[secretKey] = secretValue;
}

Store.prototype.get = function(key) {
  return this[key];
};

const store = new Store();
const revealed = store.get(secretKey);
console.log(revealed);

❓ KaTeX: The Fastest Math Typesetting Library for the Web All these AI And machine learning papers and blog posts these days are crammed with mathematical notation, so how about a no dependency, TeX-based approach to rendering them? The sandbox demo page shows off how smooth it is. Emily Eisenberg and Sophie Alpert

CHALLENGE

const secret = 'hidden';
function revealSecret() {
  const secret = 'revealed';
  const obj = { secret: 'object secret' };
  with (obj) {
    return () => secret;
  }
}

const mySecret = revealSecret()();
console.log(mySecret);

😯 Motion Canvas: Create Dynamic Canvas-Rendered Animations There’s two parts. A library where you use generator functions to procedurally define animations, and an editor that provides a real-time preview of said animations which you can see in action here. Motion Canvas

CHALLENGE

function* genFunc() {
  yield Symbol('A');
  yield new Function('return this')();
}

const obj = { key: genFunc().next().value };
obj.key = genFunc().next().value;

console.log(obj.key === globalThis);

CHALLENGE

let obj1 = { key: 'value1' };
let obj2 = { key: 'value2' };

const map = new Map();
const weakMap = new WeakMap();

map.set(obj1, 'mapValue');
weakMap.set(obj2, 'weakMapValue');

obj1 = null;  // Changing reference
obj2 = null;  // Changing reference

console.log(map.has(obj1));
console.log(weakMap.has(obj2));

✌️ SOME UPDATES JavaScript Weekly