How to properly compose node?

[fallen fox]

Hello! Fairly new to Godot but experienced gamedev/programmer here. I have a design question about a problem I stumbled upon. I want to have buildings and units that can be damaged. I want to be able to damage things without knowing if it's a building or a unit, and I don't want to duplicate the damageable logic. So I came up with the straightforward class diagram attached as a picture.

My problem is that Building is a StaticBody3D and Unit is a CharacterBody3D (or KinematicBody3D for Godot 3.x) hence I can't have a single hierarchy. So far I for-see the following solutions:

1. Make Damageable extends CharacterBody3D, the buildings will be dynamic bodies. Simple and should work.
2. Make Damageable extends Node and add the 'logic' node as a child of the root body node. Kind of like a composition I guess? Seems more 'correct' but requires more work and might introduce coupling.

Any though or other ways/patterns to solve this in an elegant manner? Would love to ear how experienced Godot dev solve this :)

[tacit vapor]

You could split damageable into staticDamageable and liveDamageable (naming up to you) and static will hold stuff that doesn't move, live stuff that does move

I don't think GDScript supports multiple inheritance, but that could also be a way

Or, alternatively, have a node Building, which has sub-nodes of Damageable, and other nodes if you so choose

So you could have building composed of damageable node, a staticTarget node for example, and other stuff

[dawn rivet]

I'm not an experience godot dev, but as far as I understood, the engine wants you to compose behavior via nodes, so I would have your scenes hold a damageable node that they can expose then through a field (or exposing only the required methods if you so choose)

You could look at it as if the scene was your object graph in dependency injection, and the held nodes are the injected fields

[vague cloud]

You could create a "DamageHandler" node and add it as a child to anything that takes damage - Then the parent can subscribe to it's "On_Damage_Taken" signal or you could handle all the health/armor/healing in the DamageHandler and just emit a "Died"/"HealthZero" signal

Consider an object "damageable" if it has a "DamageHandler" child