Peterbe.com

If you go to https://github.com/peterbe it lists the most recent blog posts here on my blog. The page is rebuilt every hour using GitHub Actions. This blog post is about how I built that, so that you can build something just like it.

In case you don't have access or it's quicker to look at a picture, this is what it looks like:

The way GitHub profiles work is you create a GitHub repo that is in the same name as your username. In my case, my username is peterbe, and the repo is thus called peterbe. So, it's named https://github.com/peterbe/peterbe. It has to be a public repo for this to work.

In that repo you have a README.md and mine looks like this: https://github.com/peterbe/peterbe/blob/main/README.md?plain=1 If you look carefully, the Markdown in that README.md contains:

<!-- blog posts -->
...
<!-- /blog posts -->

By default, HTML comments work in GitHub-flavored Markdown just like they do in HTML.

Then, I have a Node script that finds that inside the file and replaces its content with a list of Markdown links.

A couple of months ago I wrote about "Node watch mode and TypeScript" which suggests using the @swc-node/register package to be able to run node on .ts file without first converting it to .js using tsc.

In Node 22, you don't even need @swc-node/register. You can use --experimental-strip-types instead. (Note the prefix "experimental"). See release notes here.

Imagine a script like this:

// example.ts

function c2f(c: number) {
  return (c * 9) / 5 + 32;
}
console.log(c2f(123));

you can execute it directly in Node v22 using:

❯ node --experimental-strip-types --no-warnings example.ts
253.4

I'm writing this blog post from an admin interface I built, which is a web app frontend for the backend behind peterbe.com. It's built as a single-page app in Vite, with React.
Vite, unlike frameworks like Remix or Next, doesn't come with its own routing. You have to add that yourself. I added React Router. Another thing you have to do yourself is a way to load remote data into the app for display and for manipulation. This is done as XHR requests happen on the client side. For that, I chose TanStack Query. If you haven't used it but used React, it's sugar for this type of code:

// DON'T DO THIS. USE TANSTACK QUERY

const [stuff, setStuff] = useState(null)
const [error, setError] = useState(null)
useEffect(() => {
  fetch('/api/some/thing')
    .then(r => r.json())
    .then(data => setStuff(data)
    .catch(err => setError(err))
}, [])

tl;dr; for Ubuntu (>=24.10) run apt install libnginx-mod-http-brotli-static

Nginx is the web server I use on my personal web server. It sits in front of static files and Python and Node backend servers.
For static files, you can make it server the files compressed with Brotli, if the equivalent file exists on disk as a .br file.
Suppose you have this:

server {
    root /path/to/my/app/dist;
    server_name myapp.example.com;

    brotli_static on; // THIS!

    location / {
        try_files $uri /index.html;
    }

    ...
}

This one always confused me but by blogging about it, hopefully, it will stick.

This does NOT work in TypeScript:

const person = {
  firstName: "peter",
  lastName: "bengtsson",
  state: "happy"
}

const keys = Object.keys(person)
const randomKey = keys[Math.floor(Math.random() * keys.length)];
const value = person[randomKey]

It works in JavaScript, but in TypeScript you get an error on the last line (from the person[randomKey]):

I have a web app that operates as a SPA (Single Page App). It's built on regular Vite + React + TypeScript. In production you just host the built static assets, but in development (for hot module reloading and stuff) I use the built-in dev server in Vite. This is what you get when you type vite without any other command line arguments.

But here's what happens, you're in the terminal and you type npm run dev and hit Enter. Then, using your trackpad or keyboard shortcuts you switch over to a browser tab and go to http://localhost:5173/. When you get there to the first request, Vite starts at the entry point, which is src/main.tsx and from there, it looks at its imports and starts transpiling the files needed. You can see what happens with vite --debug transform.

With debug:

Suppose you have a function, written in TypeScript, that is fine and complete. Now you want to write a function that works like that one but with just some slightly more parameters and other differences. It's not too different from a decorator function.

Extending the list of parameters

Let's imagine that you already have this function:

type Operation = "sum" | "sub" | "mul" | "div"

function calculator(a: number, b: number, op: Operation) {
  if (op === "sum") return a + b
  if (op === "sub") return a - b
  if (op === "mul") return a * b
  if (op === "div") return a / b
  throw new Error(op)
}

And this could, for the sake of argument, be in a different file and/or possibly outside your control. What you now want to do is write a new function that takes those same arguments, plus one more. And importantly, you don't want to have to spell out all the arguments one more time.

First, the WRONG way to solve this:

import { calculator } from './calculator' // The code in the snippet above

type Operation = "sum" | "sub" | "mul" | "div"

function doubleCalculator(a: number, b: number, op: Operation, c: number) {
  return calculator(calculator(a, b, op), c, op)
}

console.log(calculator(1, 2, "sum")) // 3
console.log(doubleCalculator(1, 2, "sum", 10)) // 13

Technically, it works, but you had to repeat the calculator function's signature.

Bun 1.1.30 came out last week. What got me intrigued is this new option to bun build which is --bytecode. With it you can create an executable, supposedly compiled partially to bytecode which means it can start even faster.

I tried it on my hylite CLI which is a CLI, built with Bun, but works in all versions of Node, that can syntax highlight code to HTML on the command line. Here's what I did:

This isn't a comprehensive in-depth analysis but I have this SPA which is built with Vite + React.
When you run npm run build it produces:

vite v5.4.8 building for production...
✓ 8210 modules transformed.
dist/index.html                             0.76 kB │ gzip:   0.43 kB
dist/assets/images-xTxpPavl.css             2.02 kB │ gzip:   0.55 kB
dist/assets/index-IHK6QBxo.css            200.12 kB │ gzip:  29.85 kB
dist/assets/index-jgmGYYS9.js               0.79 kB │ gzip:   0.51 kB
dist/assets/open-graph-image-Ca6hLYnz.js    1.47 kB │ gzip:   0.82 kB
dist/assets/images-CwbhV2EW.js             28.75 kB │ gzip:  10.37 kB
dist/assets/pageviews-C6NSq649.js         378.67 kB │ gzip: 106.42 kB
dist/assets/index-HpyQl1NK.js             490.15 kB │ gzip: 154.11 kB
✓ built in 4.46s

Last time I uploaded a video was only a few months ago but one thing that I've improved, since that video, is the wrist alignment at the top of the swing. Neither video does a perfect job of showing this but it's a least a bit better now.

I think what I still have to work on to slow down, and find a smooth and slow tempo, as the club travels up in the back swing.