Ask HN: CI and Tests for Personal Project

How often (if ever) do you include testing, CI, typescript, etc for personal projects that only you are working on.

I'm working on a project for a buddy and I'm the only developer. I'm wondering if I should take the time to set up CI, tests and include typscript and any other tools along those lines. I understand how these tools are useful with a team, but in my opinion they don't do as much for a team of one. I am using a git repo but thats more as a code backup and for branching.