Fix dual wield skills with "both weapons hit..." combining into a single hit

spec/System/TestAttacks_spec.lua

@@ -282,4 +282,166 @@ describe("TestAttacks", function()
 		assert.is_true(math.abs(bifurcateChance - build.calcsTab.mainOutput.MainHand.CritBifurcates) < 0.000001)
 		assert.are.equals(1 + critBonusMultiplier, build.calcsTab.mainOutput.MainHand.AverageHit)
 	end)
+
+	-- Dual Wield tests
+	local setupDualWieldTestConditions = function()
+		local slowHighDmgMace = [[  
+			Slow High Crit High Damage Mace
+			Marauding Mace
+			Quality: 0
+			200% increased physical damage
+			100% increased critical hit chance
+			-25% increased attack speed
+		]]
+
+		local fastLowDmgMace = [[  
+			Fast Low Crit Low Damage Mace
+			Marauding Mace
+			Quality: 0
+			-50% increased physical damage
+			-100% increased critical hit chance
+			50% increased attack speed
+		]]
+
+		build.itemsTab:CreateDisplayItemFromRaw(slowHighDmgMace)
+		build.itemsTab:AddDisplayItem()
+		runCallback("OnFrame")
+		build.itemsTab.slots["Weapon 1"]:SetSelItemId(build.itemsTab.items[1].id)
+
+		build.itemsTab:CreateDisplayItemFromRaw(fastLowDmgMace)
+		build.itemsTab:AddDisplayItem()
+		runCallback("OnFrame")
+		build.itemsTab.slots["Weapon 2"]:SetSelItemId(build.itemsTab.items[2].id)
+
+		build.configTab.input.customMods = [[
+			nearby enemies have 100% less armour
+			your hits can't be evaded
+		]]
+		build.configTab:BuildModList()
+		runCallback("OnFrame")
+	end
+
+	local function harmonicMean(a, b)
+		return 2 / (1/a + 1/b)
+	end
+
+	it("correctly calculates dual wield DPS for double hits", function()
+		setupDualWieldTestConditions()
+		build.skillsTab:PasteSocketGroup("skillId:MeleeMaceMacePlayer Mace Strike 20/0  1")
+		runCallback("OnFrame")
+		build.calcsTab:BuildOutput()
+		runCallback("OnFrame")
+
+		-- Attack Speed
+		local mainHandSpeed = build.calcsTab.mainOutput.MainHand.Speed
+		local offHandSpeed = build.calcsTab.mainOutput.OffHand.Speed
+		local combinedSpeed = harmonicMean(mainHandSpeed, offHandSpeed)
+		assert.are.equals(round(combinedSpeed, 4), round(build.calcsTab.mainOutput.Speed, 4))
+
+		-- Average Hit
+		local mainHandAvgDmg = build.calcsTab.mainOutput.MainHand.AverageDamage
+		local offHandAvgDmg = build.calcsTab.mainOutput.OffHand.AverageDamage
+		local combinedAvgDmg = build.calcsTab.mainOutput.AverageDamage
+		assert.are.equals(round((mainHandAvgDmg + offHandAvgDmg) / 2, 4), round(combinedAvgDmg, 4))
+
+		-- DPS (hits twice per attack)
+		local combinedDPS = build.calcsTab.mainOutput.TotalDPS
+		assert.are.equals(round(combinedAvgDmg * combinedSpeed * 2,4), round(combinedDPS,4))
+	end)
+
+	it("correctly calculates dual wield crit chance for double hits", function()
+		setupDualWieldTestConditions()
+		build.skillsTab:PasteSocketGroup("skillId:MeleeMaceMacePlayer Mace Strike 20/0  1")
+		runCallback("OnFrame")
+		build.calcsTab:BuildOutput()
+		runCallback("OnFrame")
+
+		-- Double hits roll crit individually per weapon, so should be average
+		local mainHandCritChance = build.calcsTab.mainOutput.MainHand.CritChance
+		local offHandCritChance = build.calcsTab.mainOutput.OffHand.CritChance
+		local combinedCritChance = (mainHandCritChance + offHandCritChance) / 2
+		assert.are.equals(combinedCritChance, build.calcsTab.mainOutput.CritChance)
+	end)
+
+	it("correctly calculates dual wield DPS for alternating hits", function()
+		setupDualWieldTestConditions()
+		build.skillsTab:PasteSocketGroup("Armour Breaker 20/0  1")
+		runCallback("OnFrame")
+		build.calcsTab:BuildOutput()
+		runCallback("OnFrame")
+
+		-- Attack Speed
+		local mainHandSpeed = build.calcsTab.mainOutput.MainHand.Speed
+		local offHandSpeed = build.calcsTab.mainOutput.OffHand.Speed
+		local combinedSpeed = harmonicMean(mainHandSpeed, offHandSpeed)
+		assert.are.equals(round(combinedSpeed, 4), round(build.calcsTab.mainOutput.Speed, 4))
+
+		-- Average Hit
+		local mainHandAvgDmg = build.calcsTab.mainOutput.MainHand.AverageDamage
+		local offHandAvgDmg = build.calcsTab.mainOutput.OffHand.AverageDamage
+		local combinedAvgDmg = build.calcsTab.mainOutput.AverageDamage
+		assert.are.equals(round((mainHandAvgDmg + offHandAvgDmg) / 2, 4), round(combinedAvgDmg, 4))
+
+		-- DPS (hits once per attack)
+		local combinedDPS = build.calcsTab.mainOutput.TotalDPS
+		assert.are.equals(round(combinedAvgDmg * combinedSpeed, 4), round(combinedDPS, 4))
+	end)
+
+	it("correctly calculates dual wield crit chance for alternating hits", function()
+		setupDualWieldTestConditions()
+		build.skillsTab:PasteSocketGroup("Armour Breaker 20/0  1")
+		runCallback("OnFrame")
+		build.calcsTab:BuildOutput()
+		runCallback("OnFrame")
+
+		-- Alternating hits roll crit individually per weapon, so should be average
+		local mainHandCritChance = build.calcsTab.mainOutput.MainHand.CritChance
+		local offHandCritChance = build.calcsTab.mainOutput.OffHand.CritChance
+		local combinedCritChance = (mainHandCritChance + offHandCritChance) / 2
+		assert.are.equals(combinedCritChance, build.calcsTab.mainOutput.CritChance)
+	end)
+
+	--[[
+		NOTE: the following section contains tests for "combined hits", which PoE2 doesn't have as of 2026-06-02,
+		which means the tests were written for a temporary test skill that will not be committed.
+		The test can be updated by simply replacing `"skillId:MeleeMaceMacePlayerCombinedTEST Mace Strike TEST 20/0  1"`
+		with actual skill data once available
+	]]
+	--[[ it("correctly calculates dual wield DPS for combined hits", function()
+		setupDualWieldTestConditions()
+		build.skillsTab:PasteSocketGroup("skillId:MeleeMaceMacePlayerCombinedTEST Mace Strike TEST 20/0  1")
+		runCallback("OnFrame")
+		build.calcsTab:BuildOutput()
+		runCallback("OnFrame")
+
+		-- Attack Speed
+		local mainHandSpeed = build.calcsTab.mainOutput.MainHand.Speed
+		local offHandSpeed = build.calcsTab.mainOutput.OffHand.Speed
+		local combinedSpeed = harmonicMean(mainHandSpeed, offHandSpeed)
+		assert.are.equals(round(combinedSpeed, 4), round(build.calcsTab.mainOutput.Speed, 4))
+
+		-- Average Hit
+		local mainHandAvgDmg = build.calcsTab.mainOutput.MainHand.AverageDamage
+		local offHandAvgDmg = build.calcsTab.mainOutput.OffHand.AverageDamage
+		local combinedAvgDmg = build.calcsTab.mainOutput.AverageDamage
+		assert.are.equals(round((mainHandAvgDmg + offHandAvgDmg), 4), round(combinedAvgDmg, 4))
+
+		-- DPS (hits twice per attack)
+		local combinedDPS = build.calcsTab.mainOutput.TotalDPS
+		assert.are.equals(round(combinedAvgDmg * combinedSpeed, 4), round(combinedDPS,4))
+	end)
+
+	it("correctly calculates dual wield crit chance for combined hits", function()
+		setupDualWieldTestConditions()
+		build.skillsTab:PasteSocketGroup("skillId:MeleeMaceMacePlayerCombinedTEST Mace Strike TEST 20/0  1")
+		runCallback("OnFrame")
+		build.calcsTab:BuildOutput()
+		runCallback("OnFrame")
+
+		-- combined hits count whole attack as crit, as long as one hand rolls crit)
+		local mainHandCritChance = build.calcsTab.mainOutput.MainHand.CritChance
+		local offHandCritChance = build.calcsTab.mainOutput.OffHand.CritChance
+		local combinedCritChance = mainHandCritChance + offHandCritChance - (mainHandCritChance * offHandCritChance / 100)
+		assert.are.equals(combinedCritChance, build.calcsTab.mainOutput.CritChance)
+	end) ]]
 end)

src/Classes/SkillsTab.lua

@@ -629,6 +629,21 @@ function SkillsTabClass:CopySocketGroup(socketGroup)
 	Copy(skillText)
 end
 
+--- Parses pasted socketGroup or custom test string to generate new socketGroup
+--- @param testInput string? optional string input mainly used for tests
+---
+--- **Expected `testInput` Format:**
+--- ```text
+--- [Label: <Group Label>] (Optional)
+--- [Slot: <Equipment Slot>] (Optional)
+--- [skillId:<id>] <Skill Name> <Level>/<Quality> [STATE] <Count> [C] [+/-CorruptLevel]
+--- ```
+--- `skillId` is only needed if skill name is not unique
+--- `STATE` only used to disable gem via `DISABLED`
+---
+--- **Example lines:**
+--- * `"skillId:LightningSpearPlayer Lightning Spear 20/7 2 C +1"` (Level 20, 7 Quality Lightning Spear, with +1 Level Corruption and Count set to 2 )
+--- * `"RhoaMountPlayer Rhoa Mount 10/0 DISABLED 1"` (Level 10, 0 quality Rhoa Mount with count 1 that has been disabled)
 function SkillsTabClass:PasteSocketGroup(testInput)
 	local skillText = sanitiseText(Paste() or testInput)
 	if skillText then
@@ -642,8 +657,21 @@ function SkillsTabClass:PasteSocketGroup(testInput)
 			newGroup.slot = slot
 		end
 		for line in skillText:gmatch("([^\r\n]+)") do
+			local currentLine = line -- reassignment to local var to avoid modifying iter var
+
+			-- Check if specific skillId was provided via `testInput`
+			local skillId = currentLine:match("^skillId:(%w+) ")
+			if skillId then
+				currentLine = currentLine:gsub("^skillId:%w+ ", "")
+			end
+
 			local nameSpec, level, quality, state, count, cFlag, cLevel =
-				line:match("^([ %a':]+) (%d+)/(%d+)%s*(%u*)%s+([%d%.]+)%s*(C?)([+%-]?%d*)%s*$")
+				currentLine:match("^([ %a':]+) (%d+)/(%d+)%s*(%u*)%s+([%d%.]+)%s*(C?)([+%-]?%d*)%s*$")
+
+			-- Ignore invalid or mismatched skillId
+			if skillId and not (self.build.data.skills[skillId] and self.build.data.skills[skillId].baseTypeName == nameSpec) then
+				skillId = nil
+			end
 			if nameSpec then
 				local skillMinion = nil
 				local skillMinionCalcs = nil
@@ -685,7 +713,8 @@ function SkillsTabClass:PasteSocketGroup(testInput)
 					enableGlobal1 = true,
 					enableGlobal2 = true,
 					skillMinion = skillMinion,
-					skillMinionCalcs = skillMinionCalcs
+					skillMinionCalcs = skillMinionCalcs,
+					skillId = skillId
 				})
 			end
 		end

src/Data/SkillStatMap.lua

@@ -278,6 +278,9 @@ return {
 ["skill_double_hits_when_dual_wielding"] = {
 	skill("doubleHitsWhenDualWielding", true),
 },
+["skill_combines_hits_when_dual_wielding"] = { -- NOTE: This is before PoE2 has "combined hit" dual wield skills, so stat will have to be updated in the future
+	skill("combinesHitsWhenDualWielding", true),
+},
 ["support_spell_echo_number_of_echo_cascades"] = {
 	mod("RepeatCount", "BASE", nil, 0, 0, {type = "SkillType", skillType = SkillType.Cascadable }),
 },