christophemarois

import { AsyncLocalStorage } from "node:async_hooks";

function createCtx<T>(name: string, defaultValue?: T) {
	const ctx = new AsyncLocalStorage<T>({ name });

	const set = (x: T) => ctx.enterWith(x);
	const maybeGet = () => ctx.getStore();
	const get = (): T => {
		const val = maybeGet();
		if (val === undefined) {

christophemarois

Keybase proof

I hereby claim:

• I am christophemarois on github.
• I am cmarois (https://keybase.io/cmarois) on keybase.
• I have a public key ASC_FRYqHGxz6zFSsGZyeK8PGOKgiCsD90h8euiHjQgXeAo

To claim this, I am signing this object:

christophemarois

/** Make sure that an unknown object is an error. If it's not, wrap it in an
 * error with a useful inspection message */
export function ensureError(err: unknown): Error {
  if (err instanceof Error) {
    return err
  }

  let data: string

  try {

christophemarois

TS/JS go-to libs

Updated Apr 2025. For looking up trending newer alternatives, use npmtrends. For Nodejs, nodejstoolbox a precompiled list of trends by category.

Universal

Standard libs

Standard libs extend the runtime with convenience helpers, structures and patterns. Use these two in order

christophemarois

/** Typed context creation helper
 * @example
 * export const [useLevel, LevelProvider] = createTypedContext<{ level: number }>('LevelContext')
 */
export function createTypedContext<T>(name: string) {
  const Context = createContext<T | null>(null)

  function useEnsuredContext() {
    const ctx = useContext(Context)
    if (ctx === null) {

christophemarois

/* eslint-disable no-console */
/**
 * Represents a deeply readonly version of a type, including nested objects,
 * arrays, sets, and maps.
 * @template T - The type to make deeply readonly.
 */
export type DeepReadonly<T> = T extends (infer R)[]
  ? ReadonlyArray<DeepReadonly<R>>
  : T extends Set<infer R>
  ? ReadonlySet<DeepReadonly<R>>

christophemarois

/** Create a wrapped AbortController that is aborted when a SIGINT/SIGTERM is received.
 * Supports auto-unregistering via explicit resource management.
 *
 * @example
 * using shutdownSignal = new ShutdownSignal()
 * shutdownSignal.throwIfAborted()
 *
 * // or
 * const shutdownSignal = new ShutdownSignal()
 * try { shutdownSignal.throwIfAborted() } finally { shutdownSignal.unregister() }

christophemarois

import { useState } from 'react'

export default function useMap<K, V>(): [
  Map<K, V>,
  {
    set: (key: K, value: V) => void
    unset: (key: K) => void
    clear: () => void
  }
] {

christophemarois

Cloudflare is a better and free ngrok. With a domain that uses it, set it up like this

1. Setup a tunnel

cloudflared tunnel login
cloudflared tunnel create test
cloudflared tunnel route dns test test.christophemarois.com

christophemarois

/** Transform the password part of a connection string URL into [redacted].
 * Useful for logging. */
export function redactPasswordFromUrl(url: string) {
  return url.replace(/^([^:]+):\/\/([^:]*):([^@]+)@/, '$1://$2:[redacted]@')
}