Random Notes

Coordinated Universal Time (UTC) is one of the greatest helps to programmers when dealing with datetime values. UTC makes my life easier, and thus raises my quality of life. Yet, it is plagued by a fallacy that I've seen many times in programmers' discussions online. This is the UTC everywhere fallacy. Even for all the nice things UTC gives us, it just doesn't solve everything.

I've written about Elixir configuration in an earlier post, describing the differences in the configuration styles. If you don't know how Elixir configuration works, I suggest reading it also. In this post, I will demonstrate a system for configuring an Elixir project using the config/runtime.exs system introduced in Elixir 1.11. This system is how I configure my projects, so feel free take it as inspiration, but it's not a law that you have to follow.

Configuring Elixir applications is a common problem point for new developers and I've seen many questions about it in the community chats. So I thought to write down my knowledge in case it helps anyone.

I've long had certain issues with modern web development, and I even wrote a little tool of my own to help me manage such an environment. So I look for ways to minimise the complexity of my setups while still maintaining some modern conveniences. Now I've started to use a setup that relies on TypeScript and modern browsers' builtin features. This is a very minimal setup consisting just of TypeScript, plain CSS, and maybe a tiny build script.

I was doing some Node.js V8 profiling work at the office near the end of the day and noticed my profile processing was taking a long time. I figured it is just processor intensive and left it running for the day while I went home. To my surprise, the next day it was still running! htop showed me it had accumulated 12 hours of CPU time and was still not finished. This led me to track down a related issue and how to fix it.

When improving Code::Stats's Atom plugin, I wanted to add the plugin version as the User-Agent header: code-stats-atom/x.y.z. I used the fetch API and set the header there but it did nothing! By googling a bit I found that User-Agent used to be a "dangerous" header that wasn't allowed to be set in browsers. It was only recently allowed, but Chromium has not implemented support for it.

People commented so nicely on my first build tool FBU that I decided to push it to the Elixir package manager Hex.pm. I renamed it, though, since people pointed out that it could be used to build anything, not just the front end. So now it's called (still unimaginatively) MBU: Mix Build Utilities.

You can find it at hex.pm/packages/mbu and the docs are in Hexdocs.

EDIT 2017-04-04: I have since renamed the project to MBU: Mix Build Utilities and published it on Hex.pm: hex.pm/packages/mbu. I have edited the links and code examples in this post to reflect that.

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tl;dr I wrote my own build tool using Elixir's Mix: Nicd/mbu.

It's no secret that I somewhat dislike the state of modern web development. JavaScript is its own terrible world, but one of the sad parts of it is the ecosystem and tooling around it. There's a lot of innovation and hard work going on in very many fragmented projects, resulting in reimplementations of already solved problems and a ton of half working, alpha quality, 0.x versioned packages with unknown support status. With these packages, you start your project by building an elaborate house of cards that is the build system. And you dread the day when you need to touch it again.

What better way to spend a slow weekend than by writing another blog engine? Plenty, actually, but that's what I did anyway. The result of this work: Mebe! This blog is now powered by a wonderful mix of Elixir and Phoenix. It has all the features that Laine had, with the addition of an actually working Disqus comment system. It's also search engine indexable, which I thought I didn't care about, until I didn't have it anymore. Not that I'm aiming for tons of visitors, but writing about some tech problem I have fixed is kind of pointless if no one can find the post by googling for it.

I had some free time this weekend, so I decided to pick up on an old piece of code I wrote back when I started learning Elixir. It's a URI parser I called Nurina (the word nurina is Finnish and means grumbling or complaining -- it sounded funny and it contains the word URI). It's not really a well put together piece of code but more of a learning excercise. I also decided to avoid using regular expressions entirely and instead used pattern matching to parse the whole URI -- an additional challenge.