Tests create a new "trees 20241231012345.csv" file in "~/Downloads"

[sadiqkhoja]

Whenever I run npm run test, a new file "trees 20241231012345.csv" is created in my downloads folder. I guess it('has the correct filename') test in data-template.spec.js is the culprit.

[matthew-white]

I actually noticed something along these lines while working on #671. When I run tests using Vitest on my local branch, a CSV file ends up being created in the repo (I'm pretty sure the same one). I didn't realize it had an effect even today under Karma. I fixed the issue in my local branch, I think by calling event.preventDefault() in the test. I'll go ahead and pull out that change into its own PR, since we can see that it's an issue even today.