From d82eeabf22693f06d8da48d23d3f111f996b9ee2 Mon Sep 17 00:00:00 2001
From: Brues <5278969+brues-code@users.noreply.github.com>
Date: Tue, 28 Jul 2026 09:12:29 -0500
Subject: [PATCH] Detect Banish via C_UnitAuras.GetUnitAuraBySpellID, not slot
 scan

The Banish immunity check hand-scanned 16 debuff slots plus 32 buff slots
(NPC overflow) for spellID 710/18647. ClassicAPI.GetUnitAuraBySpellID walks
the whole aura array in one call per rank, so it finds the debuff wherever it
lands -- including an NPC's overflow buff slots -- dropping the two loops and
the UnitIsPlayer gate. Wrapper added alongside UnitHasDispelType.
---
 ClassicAPI.lua | 13 +++++++++++++
 Utility.lua    | 31 ++++++-------------------------
 2 files changed, 19 insertions(+), 25 deletions(-)

diff --git a/ClassicAPI.lua b/ClassicAPI.lua
index f2a9c63..67c03ab 100644
--- a/ClassicAPI.lua
+++ b/ClassicAPI.lua
@@ -82,6 +82,19 @@ function API.UnitHasDispelType(unit, dispelType, helpful)
     return scanDispel(indexFn, unit, dispelType, wantAny)
 end
 
+-- First matching aura on `unit` by spellID, or nil. With no filter it walks the
+-- whole aura array (helpful then harmful), so it finds a debuff even when it has
+-- overflowed into an NPC's buff slots -- no 16+32 slot scan, no UnitIsPlayer
+-- gate. filter ("HELPFUL"/"HARMFUL") restricts the search. Returns the modern
+-- AuraData (spellId, name, applications, duration, expirationTime, dispelName, ...).
+function API.GetUnitAuraBySpellID(unit, spellID, filter)
+    if not unit or not spellID then return nil end
+    if type(C_UnitAuras) ~= "table" or type(C_UnitAuras.GetUnitAuraBySpellID) ~= "function" then
+        return nil
+    end
+    return C_UnitAuras.GetUnitAuraBySpellID(unit, spellID, filter)
+end
+
 --------------------------------------------------------------------------------
 -- GetUnitSpeed
 --------------------------------------------------------------------------------
diff --git a/Utility.lua b/Utility.lua
index 3cce898..35a9fd5 100644
--- a/Utility.lua
+++ b/Utility.lua
@@ -8629,31 +8629,12 @@ function CleveRoids.CheckImmunity(unitId, spellOrSchool)
     -- Universal debuff-based immunities (Banish, etc.)
     -- Banish makes target immune to most damage schools (not all spells)
     do
-        local hasBanish = false
-
-        -- Check debuffs first (Banish: 710 = Rank 1, 18647 = Rank 2)
-        for i = 1, 16 do
-            local texture, stacks, dtype, spellID = UnitDebuff(unitId, i)
-            if not texture then break end
-
-            if spellID == 710 or spellID == 18647 then
-                hasBanish = true
-                break
-            end
-        end
-
-        -- Overflow handling: debuffs can overflow into buffs on NPCs
-        if not hasBanish and not UnitIsPlayer(unitId) then
-            for i = 1, 32 do
-                local texture, stacks, spellID = UnitBuff(unitId, i)
-                if not texture then break end
-
-                if spellID == 710 or spellID == 18647 then
-                    hasBanish = true
-                    break
-                end
-            end
-        end
+        -- Banish: 710 = Rank 1, 18647 = Rank 2. One by-spellID lookup each --
+        -- C_UnitAuras walks the whole aura array, so it finds the debuff even when
+        -- it has overflowed into an NPC's buff slots (no manual slot scan / overflow gate).
+        local API = CleveRoids.ClassicAPI
+        local hasBanish = (API.GetUnitAuraBySpellID(unitId, 710)
+            or API.GetUnitAuraBySpellID(unitId, 18647)) and true or false
 
         -- If Banished, check what's being tested for immunity
         if hasBanish then