I started working on the itch.io desktop app over 4 years ago.

It has arguably been my main project ever since, along with companion projects like butler, capsule and many smaller libraries.

I'm fuzzy on the initial history, but I remember the codebase went through a lot of changes. As early as 2014, the whole codebase was ported from vanilla JavaScript to TypeScript. In 2016, I released . In 2018, I released a postmortem for v25 (which I then deleted).

A little while ago, I wrote an article on things that can go wrong when downloading, it listed a series of reasons, from network problems to invalid content to imperfect hardware that may occur when initially installing a game.

This article discusses what methods we can use to upgrade a game to a later version, when an older version has been successfully installed.

When I get a little bit too emotional about my current baby, the itch.io app, there's always a timely support ticket reminding me that it is currently, still a glorified game downloader.

However true that is, that doesn't mean it's easy! In the past year, I've had to account for a bunch of failure conditions that can happen, some of which I didn't realize were even possible. Let's review them, for fun!

I've been working on the itch.io desktop app for about a year now, so I thought I'd make a quick recap:

At the time of this writing, the app has been downloaded about 460K times (including updates). Not counting the back-end, the app and its various components are made up of around 100K lines of code (mostly javascript and golang), most of which is .