Notes

Have you heard of semantic Javascript ?

You probably answered "No" because I just thought of it 😇

Everyone knows they should be writing semantic HTML but why not apply the same standards to a "real" programming language.

Semantic programming is all about using the constructs a language provides in such a way as to convey intent to the target audience, whether that be human or machine. In HTML we have the classic example of using the <footer> tag instead of just spamming <div> everywhere. Lets apply that logic to Javascript.

Here's some non-semantic JS.

let arr = [1, 2, 3]
1for(let i = 0; i < arr.length; i++) {
  arr[i] =2arr[i] * 2
}

now for something semantic

// we are doing the exact same thing as before, just better.
let arr = [1, 2, 3]
arr = arr.1map((x) => x * 2)

I think you get the idea...

But just in case, here is another scenario...

1while(i < arr.length) {
  ...
  // do some operation
  res = ...
}

Compare the above to this:

let res = arr.1reduce((acc, cur) => {
  ...
  // do some operation
},{})

So.. what do you think?

Ok, maybe this is just an excuse to get you to do some functional programming.

You got me! 😘

Here's how to burn audio to a CD from the command line.

# Remove spaces from filenames
for f in *; do mv "$f" `echo $f | tr ' ' '_'`; done
# Convert all tracks to wav
for i in $( ls ); do ffmpeg -i $i $i.wav; done
# Normalize the volume across all tracks
normalize -m *.wav
# Burn to disk
sudo wodim -v -dev='/dev/cdrom' -audio -pad *.wav

So this is one of the first times I have actually come across a hurdle when it comes to developing software on old computers. A couple days ago I started experimenting with bun, which is amazing by the way. One of the big selling points is that it is really fast, but this speed seems to come at a cost...

As I use NixOS, I installed it the usual way by adding it to my configuration.nix. But alas, life isn't always simple. It seems to install ok, but when I tried to run bun I got an error immediately:

illegal hardware instruction (core dumped)

Wow an actually hardware error! I haven't seen one of those since I was trying some overclocking! So the problem comes down to the fact that bun uses some cutting edge CPU instructions that weren't around in 2012. Now, on other Linux distributions you can simply use a bash script to install bun à la:

curl -fsSL https://bun.sh/install | bash

Apparently it checks your CPU and in the event it finds something of a certain vintage it installs a baseline version of bun which I guess doesn't use any of the funky CPU instructions it would usually. Unfortunately the nix package does not at the time of writing do this. There is actually a PR open to fix this but it has not been merged yet. So for the time being you can basically just take the code from the PR, save it to a file locally and build the baseline version yourself.

1. Download and save this file.
2. Now to build is, run:

nix-build -E 'with import <nixpkgs> {}; callPackage ./default.nix {}'

3. You should now be able to run bun by doing:

./result/bin/bun

I witnessed this absolute corker of a bug in the office today.

After a force reboot (its a long story), we noticed that the cursor was flickering on my colleague's Ubuntu laptop. After some googling, we realised that this flickering only happens at 200% fractional scaling. Setting to any other value like 175%, 150% etc. works perfectly fine.

https://askubuntu.com/questions/1234189/cursor-flickers-on-primary-display-when-fractional-scaling-is-enable-for-dual-mo

Despite the link above being more than three and a half years old, it appears that even today, this bug can still be observed in the wild, in its natural habitat, on Ubuntu.

It's taken me far too long to discover this foot-gun in express.

I started a new express project the other day and realised that my request bodies were all empty! Spent a good hour thinking it was a problem in the client or the proxy etc... but was actually just because I forgot to apply these two middlewares.

So the question is, why are these middlewares not enabled by default????

const app = express()
  // this populates req.body when the payload is json
  app.use(express.json({ type: "application/json" }))
  // this populates req.body when the payload is urlencoded 
  // (e.g when a form gets submitted)
  app.use(express.urlencoded({ extended: true }))
  ...

Sensible defaults are just something we don't deserve I guess...