This year I want to become a better programmer. I ordered the book clean code and want to focus on writing more and better unit tests.

If anyone has any tips on how to improve or how to get tips on your code

Clean Code is actually a good read!

I recommend you to go into TDD (test first, implement second for having
better code quality in the end)

@2erXre5 Thanks, I'll look more into that

When you do more unit tests, you will notice how some things are easier to test than others. This will make you design classes differently and make them simpler as a result.

Do you have a tool that shows which codepaths are covered by tests?

@CWins no, not yet. I'm currently using vs code with node typescript and test with jest. Any suggestions?

Clean code is a good start!
Be sure to watch "Uncle Bob's" talks on YT, too, they are quite insightful.

In addition, I'd recommend to let a tool help you to write clean code and improve your code over time (there are many!). My company (and I ;) are working on a code quality tool called "Teamscale" which is free for students. Let me know if you're interested ;)

@Hopstar
Not for VS Code, for VS there's AxoCover.

A quick google on jest and "test coverage" gave results, so there should be something.