rauschma

Books on TypeScript

• The official “TypeScript Handbook” is a good reference for the language. It currently has a few holes that are filled by the release notes and GitHub pull requests (which handbook and release notes link to).

• “TypeScript Deep Dive” by Basarat Ali Syed was not updated much after 2020 – e.g., it does not cover template string types. But this book is still a valuable resource.

• “The Concise TypeScript Book” by Simone Poggiali

Coding exercises

rauschma

Node.js: functionality useful for CLI apps that’s now built in

Did I forget anything?

• Single executable applications
• Test runner
• util.styleText()
• util.parseArgs()
• node:sqlite
• File operations:

rauschma

// Experiment: I’m not sure if I would use this myself.

const call = Symbol('call');
class Callable {
  constructor() {
    // Can’t use .bind() here. Not sure why. Maybe the result doesn’t
    // interact well with Object.setPrototypeOf().
    const _this = (...args) => new.target.prototype[call].call(_this, ...args);
    Object.setPrototypeOf(_this, new.target.prototype);
    return _this;

rauschma

//========== Testing types ==========

const expectType = <Type>(_: Type): void => void 0;
type TypeEqual<Target, Value> = (<T>() => T extends Target
  ? 1
  : 2) extends <T>() => T extends Value ? 1 : 2
  ? true
  : false;

//========== applyPartial ==========

rauschma

// Q: Why not an object literal?
// A: Then you have to create separate constants for the symbols:
//    https://2ality.com/2025/01/typescript-enum-patterns.html#using-symbols-as-property-values

type PropertyValues<Obj> = Obj[keyof Obj];
function createEnum<C extends new (...args: unknown[]) => unknown>(enumClass: C): Omit<C, 'prototype'> {
  return enumClass;
}

const Color = createEnum(class {

rauschma

type CreateTuple<Len extends number, Acc extends unknown[] = []> = 
  Acc['length'] extends Len
  ? Acc
  : CreateTuple<Len, [...Acc, true]>;
;
type Length<Tup extends Array<unknown>> =
  Tup['length']
;

type Unshift<Tuple extends Array<unknown>, Value> =

rauschma

// This code is now an npm package: https://github.com/rauschma/asserttt

rauschma

// Slightly modified version of: https://github.com/es-shims/RegExp.escape/blob/main/test/tests.js

import test from 'node:test';
import assert from 'node:assert/strict';
import {regExpEscape as escape} from './regexp-escape.mjs';

const forEach = (arrayLike, callback) => Array.prototype.forEach.call(arrayLike, callback);
const inspect = String;

test('strings', function (st) {

rauschma

Mastodon for people who are new to social media

In this blog post, I try to explain Mastodon to people who are not familiar with social media and/or beginner computer users. I try to be as jargon-free as I can.

Structure of this blog post:

• Reading section 1 and 2 takes a bit of effort: They explain important background knowledge for Mastodon. But, in my opinion, the effort is worth it because you’ll find it much easier to use Mastodon. Not having this knowledge can prevent even otherwise advanced computer users from enjoying Mastodon.

• Section 3 is brief and mentions first steps for actually getting started with Mastodon.

rauschma

javascript:{
  const text = getSelection().toString().trim();
  if (text.length > 0) {
    const urlToHighlight = new URL(location);
    urlToHighlight.hash = '#:~:text=' + encodeURIComponent(text);
    navigator.clipboard.writeText(urlToHighlight.href)
      .catch((error) => {
        alert(String(error));
      });
  }