how do you tell a junior dev on your team there code is shit and please don't push to the main codebase without approval first,
without crushing them and and sounding like an ass cause there a good person just a n00b developer

Lock down the main and develop branch and enforce pull requests?

Every developer makes mistakes that can be caught in reviews

If he's really a junior, he'd appreciate review. Tell him to make use of branches. And that'd you'd review his work and give him cookies if he does a good job.

Why can anyone push to the main branch?

Don't do this, stick some proper permissions on the repo, and get PRs requiring at least 2 senior reviewers set up.

What I did was wall to the guy who's code I was reviewing and told him:

"You're joking, right? There's no way I'm letting this pass, you can't X and Y... I left you comments, check it out because this is unacceptable"

True story, just a different language! They don't hate me and I have to say all code from them since was a lot more thought out...

@nibor well i mean we are a very small team in a even smaller company

@butwhytho no excuse for not setting up restrictions :p

@butwhytho Still, proper procedure prevents dumb mistakes

What if a junior destroys his local branch and then accidentally force pushes to master?

@butwhytho I feel this, small companies tend to forget smaller details. It sucks but the only thing you can do is trying and lock stuff down and push a standard of rules when handling repo's.