When a slime or magma cube is damaged, it will not aggro on its attacker unless it can see them

Slimes and magma cubes have a very rudimentary AI, to the point where they seemingly will not respond to attacks unless they can see their attacker. This allows unarmored players with Invisibility to attack them with near impunity. It also means players can, for example, use splash harming on them from around a corner and retreat without fear of pursuit, but this is much less of an issue and may in any case be intended, although if so it would be unique behavior for a hostile mob.

To reproduce

1. /effect give @s minecraft:invisibility 200 0 true

2. Disrobe, and switch to survival if you are not already in that mode

3. /summon minecraft:slime ^ ^1 ^3 {Size:3}

4. Attack the slime, making sure not to get too close
   ❌ It does not gain aggro on you

Expected result

The slime would retaliate after being attacked.