Help us make GNOME Calendar rock-solid by expanding the test suite!4 min read

GNOME Calendar 45 will be a groundbreaking release in terms of UX (more on that later?), performance, and to some extent, reliability (we’ve at least solved two complex crashers recently, including a submarine Cthulhu crasher heisenbug and its offspring)… and yet, I think this might be “just the beginning” of a new era. And a beginning… is a very delicate time.

If you’ve tried to use GNOME Calendar in the past decade or so, you’ve certainly encountered one of the many bugs related to timezones, daylight saving time, and all of that crazy stuff that would make Tom Scott curl up in a corner and cry. But it doesn’t have to be that way, and in fact, there is a way for anyone who knows a bit of C programming to help us build the tools to solve this mission-critical problem.

Today, I’d like to urge you to help in writing some automated tests.
The sooner our test suite can grow, the faster we can make GNOME Calendar rock-solid.

The "Anime girl hiding from Terminator" meme, with the Terminator labelled "The automated tests we need" and the anime girl labelled "The current GNOME Calendar codebase"

As I explain in this epic blocker ticket:

Why is this suddenly mission-critical now?

I believe a boosted test suite is now becoming mission-critical, because in my logical ordering of the dependency chain for this new roadmap I devised in 2023, I have determined that timezones/DST/midnight backend+views reliability blocks almost everything left: you can’t expand the UI and UX featureset to encompass meetings & timezones management unless you have a rock-solid, reliable backend and views/representation that you can trust to begin with (why create nice UIs if the users won’t trust the resulting events/data/views?)

So we need to fix those ugly issues once and for all. And there’s pretty much only one way to do this kind of daunting bugfixing work efficiently and sustainably: with test-driven development.

Once we have those tests, I trust that we will be able to make the app pretty much bulletproof.

Having extensive automated test coverage will allow us to confidently/safely fix some of the first “fundamental” compliance bugs there, and I can bet that by doing so, we would incidently solve tons of other issues at once—I wouldn’t be surprised if this would allow us to solve 50 issues or more. This will not only make a ton of existing users happy (and make GNOME Calendar viable for a ton more new users), but also make contributors happy because we will be able to resolve and close a ton of tickets cluttering our view. It’s all part of a flywheel of sustainability here.

“How hard can it be?”

While writing such tests might not be easy to do for a “beginner programmer who does not know the C language”, it is a good “newcomer contributor” task for someone who already knows C programming and are looking to make a lasting quality impact on a popular FLOSS desktop productivity application that many people love.

Maybe you, or a friend or colleague, would be interested by this challenge (while existing GNOME Calendar contributors keep fixing bugs at the same time)? This blog post is retootable if you want to spread the word there, too.

Ready to help us improve reliability?

If the above sounds like an interesting way to help the project, read the detailed ticket for more details, join us on the cozy “#gnome-calendar:gnome.orgMatrix channel (mapped to the #gnome-calendar IRC channel on and get started!