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@joepie91
joepie91 / random.md
Last active November 1, 2025 17:37
Secure random values (in Node.js)

Not all random values are created equal - for security-related code, you need a specific kind of random value.

A summary of this article, if you don't want to read the entire thing:

  • Don't use Math.random(). There are extremely few cases where Math.random() is the right answer. Don't use it, unless you've read this entire article, and determined that it's necessary for your case.
  • Don't use crypto.getRandomBytes directly. While it's a CSPRNG, it's easy to bias the result when 'transforming' it, such that the output becomes more predictable.
  • If you want to generate random tokens or API keys: Use uuid, specifically the uuid.v4() method. Avoid node-uuid - it's not the same package, and doesn't produce reliably secure random values.
  • If you want to generate random numbers in a range: Use random-number-csprng.

You should seriously consider reading the entire article, though - it's

@joepie91
joepie91 / sessions.md
Last active September 12, 2025 09:50
Introduction to sessions

While a lot of Node.js guides recommend using JWT as an alternative to session cookies (sometimes even mistakenly calling it "more secure than cookies"), this is a terrible idea. JWTs are absolutely not a secure way to deal with user authentication/sessions, and this article goes into more detail about that.

Secure user authentication requires the use of session cookies.

Cookies are small key/value pairs that are usually sent by a server, and stored on the client (often a browser). The client then sends this key/value pair back with every request, in a HTTP header. This way, unique clients can be identified between requests, and client-side settings can be stored and used by the server.

Session cookies are cookies containing a unique session ID that is generated by the server. This session ID is used by the server to identify the client whenever it makes a request, and to associate session data with that request.

*S

@israelcrux
israelcrux / save-and-restore-contenteditable-selection.js
Last active January 14, 2024 13:58
Save and Restore DOM text selection
function saveSelection() {
if (window.getSelection) {
var sel = window.getSelection();
if (sel.getRangeAt && sel.rangeCount) {
return sel.getRangeAt(0);
}
} else if (document.selection && document.selection.createRange) {
return document.selection.createRange();
}
return null;
@threepointone
threepointone / glam-for-css-folks.md
Last active September 4, 2022 07:43
why css purists will love glam

I made a little styling lib called glam

(some features are in development)

one

let's start off with the simplest use case. we'll make an 'index.html' page, and assume we've setup our js bundler to output bundle.js

@kimamula
kimamula / sort.js
Created October 28, 2017 15:46
JavaScript asynchronous sort
/**
* return the mid value among x, y, and z
* @param x
* @param y
* @param z
* @param compare
* @returns {Promise.<*>}
*/
async function getPivot(x, y, z, compare) {
if (await compare(x, y) < 0) {
@threepointone
threepointone / for-snook.md
Last active December 3, 2024 21:48
For Snook

https://twitter.com/snookca/status/1073299331262889984?s=21

‪“‬In what way is JS any more maintainable than CSS? How does writing CSS in JS make it any more maintainable?”

‪Happy to chat about this. There’s an obvious disclaimer that there’s a cost to css-in-js solutions, but that cost is paid specifically for the benefits it brings; as such it’s useful for some usecases, and not meant as a replacement for all workflows. ‬

‪(These conversations always get heated on twitter, so please believe that I’m here to converse, not to convince. In return, I promise to listen to you too and change my opinions; I’ve had mad respect for you for years and would consider your feedback a gift. Also, some of the stuff I’m writing might seem obvious to you; I’m not trying to tell you if all people of some of the details, but it might be useful to someone else who bumps into this who doesn’t have context)‬

So the big deal about css-in-js (cij) is selectors.

// Processing code by Etienne JACOB
// motion blur template by beesandbombs
// opensimplexnoise code in another tab might be necessary
// --> code here : https://gist.github.com/Bleuje/fce86ef35b66c4a2b6a469b27163591e
int[][] result;
float t, c;
float ease(float p) {
const {useCallback, useEffect, useReducer, useRef} = require('react');
let effectCapture = null;
exports.useReducerWithEmitEffect = function(reducer, initialArg, init) {
let updateCounter = useRef(0);
let wrappedReducer = useCallback(function(oldWrappedState, action) {
effectCapture = [];
try {
let newState = reducer(oldWrappedState.state, action.action);
@enepomnyaschih
enepomnyaschih / base64.js
Last active October 22, 2025 23:55
https://www.npmjs.com/package/byte-base64 - Encode JS Uint8Array, simple array of bytes or native JS string to base64 and back
/*
MIT License
Copyright (c) 2020 Egor Nepomnyaschih
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
@acutmore
acutmore / README.md
Last active August 10, 2025 02:26
Emulating a 4-Bit Virtual Machine in (TypeScript\JavaScript) (just Types no Script)

A compile-time 4-Bit Virtual Machine implemented in TypeScript's type system. Capable of running a sample 'FizzBuzz' program.

Syntax emits zero JavaScript.

type RESULT = VM<
  [
    ["push", N_1],         // 1
    ["push", False],       // 2
 ["peek", _], // 3