Determine whether a unit is in combat or has aggro.

affectingCombat = UnitAffectingCombat("unit");

Parameters

Arguments

("unit")

unit 

String - The UnitId of the unit to check (Tested with "player", "pet", "party1", hostile "target")

Returns

affectingCombat 

Flag - Returns 1 if the unit is in combat or has aggro, nil otherwise.

Details

Returns true when initiating combat.

Returns true if aggroed, even if enemy doesn't land a blow.

If a hunter, then returns true shortly after pet enters combat.

If using timed spell such as aimed shot, returns true when spell fires (not during charge up).

Returns to false on death.

Returns false if the unit being checked for aggro is out of range, or in another zone.

Note: returns false if a unit is proximity-aggroed. It wont return true until it either attacks or is attacked.