The friendships that survived a real fight usually come out stronger. The seam holds better than the fabric.

A friendship that has come through a real disagreement holds information the untested ones do not. You both found out that it does not collapse when somebody is angry, and that the other person comes back. Before that happens everyone is slightly careful, because nobody knows what the floor is made of. Afterward you can say harder things, which is most of what closeness actually is.

If you are in the middle of one, stay in the room and aim at repair rather than winning. Go back later and say calmly what you should have said then. The goal is not avoiding fights, it is being two people who return.