Now that I've figured out how to dynamically import modules and use
those modules as outputs, the next step is to ensure that these modules
work as intended when being used by end users.
NixOS offers a built-in testing solution that enables us to conveniently
spin up virtual machines with a given configuration, then verify their
correctness through python scripting.
The lib.nix file in particular is based on Jörg Thalheim's very useful
blog post that explains how to use the built-in testing functionality
with Nix flakes, which isn't covered in official documentation.
See: https://blog.thalheim.io/2023/01/08/how-to-use-nixos-testing-framework-with-flakes/
Note that these tests were originally made to prevent dead code from
being in the repository, although a proper coverage solution would
likely be more useful long-term.
2 months ago, I figured out how to make Crystal work on NixOS and made
an upstream PR to fix Crystal being unable to find -lpcre. Unfortunately,
that change hasn't been merged yet and I even encountered a core dumped
error when trying to build Crystal myself recently.
Although people may be busy, I am concerned about the popularity of
Crystal relative to other languages. It could be the case that the build
was broken for so long precisely because no one used Crystal, and that
the language isn't popular enough to generate comments on the patch either.
In any case, JavaScript/TypeScript is here to stay, and it certainly has
better tooling and community support than Crystal at the moment. Deno
has been going strong for a few years now, and now that I know Rust, I
can also contribute to it if I want to.
