Add support for the Infernal Legion skill

spec/System/TestAilments_spec.lua

@@ -28,4 +28,56 @@ describe("TestAilments", function()
 
 		assert.are.equals(1.1, build.calcsTab.mainOutput.PoisonEffMult)
 	end)
+
+	-- Pseudo-hits: a skill flagged with skillData.pseudoHitAilment inflicts that one
+	-- ailment as though dealing its hit damage, but the hit itself deals no damage
+	-- (e.g. Infernal Legion's burn). No in-tree skill sets the flag yet, so run the
+	-- calcs directly on an env with the flag injected.
+	describe("pseudo-hit ailment sources", function()
+		local function setupFireball(customMods)
+			build.skillsTab:PasteSocketGroup("Fireball 20/0  1\n")
+			runCallback("OnFrame")
+			build.configTab.input.customMods = customMods
+			build.configTab:BuildModList()
+			runCallback("OnFrame")
+		end
+
+		local function performWith(pseudoHitAilment)
+			local calcs = build.calcsTab.calcs
+			local env = calcs.initEnv(build, "MAIN")
+			env.player.mainSkill.skillData.pseudoHitAilment = pseudoHitAilment
+			calcs.perform(env)
+			return env.player.output
+		end
+
+		it("deals no hit damage but still applies its ailment", function()
+			setupFireball("100% chance to Ignite")
+			local real = performWith(nil)
+			assert.True(real.TotalDPS and real.TotalDPS > 0)
+			assert.True(real.IgniteDPS and real.IgniteDPS > 0)
+			local pseudo = performWith("Ignite")
+			assert.are.equals(0, pseudo.TotalDPS)
+			assert.are.equals(0, pseudo.AverageDamage)
+			-- the ailment still sees the full stored hit damage
+			assert.are.equals(real.IgniteDPS, pseudo.IgniteDPS)
+		end)
+
+		it("does not let other on-hit ailments ride on the notional damage", function()
+			setupFireball("100% chance to Ignite\n100% chance to Poison on Hit\nAdds 50 to 70 Chaos Damage to Spells")
+			local real = performWith(nil)
+			assert.True(real.PoisonDPS and real.PoisonDPS > 0)
+			local pseudo = performWith("Ignite")
+			assert.True(not pseudo.PoisonDPS or pseudo.PoisonDPS == 0, "pseudo-hit must not produce poison DPS")
+			assert.are.equals(real.IgniteDPS, pseudo.IgniteDPS)
+		end)
+
+		it("still scales with ailment magnitude", function()
+			setupFireball("100% chance to Ignite")
+			local base = performWith("Ignite").IgniteDPS
+			assert.True(base and base > 0)
+			setupFireball("100% chance to Ignite\n50% increased Magnitude of Ailments")
+			local scaled = performWith("Ignite").IgniteDPS
+			assert.True(math.abs(scaled / base - 1.5) < 1e-6, string.format("expected 1.5x, got %.6fx", scaled / base))
+		end)
+	end)
 end)

spec/System/TestInfernalLegion_spec.lua

@@ -0,0 +1,122 @@
+describe("TestInfernalLegion", function()
+	before_each(function()
+		newBuild()
+	end)
+
+	-- Helper: minion supported by Infernal Legion, with the minion pointed at the IL skill.
+	-- Set any config/customMods before calling this so the build picks them up.
+	local function setupIL()
+		build.configTab:BuildModList()
+		build.skillsTab:PasteSocketGroup("Skeletal Warrior 20/0  1\nInfernal Legion I 1/0  1\n")
+		runCallback("OnFrame")
+		build.skillsTab:SetDisplayGroup(build.skillsTab.socketGroupList[1])
+		runCallback("OnFrame")
+		local env = build.calcsTab.mainEnv
+		local ilIndex
+		for i, s in ipairs(env.minion and env.minion.activeSkillList or {}) do
+			local ge = s.activeEffect and s.activeEffect.grantedEffect
+			if ge and ge.id == "InfernalLegion" then ilIndex = i break end
+		end
+		assert.is_not_nil(ilIndex, "Infernal Legion should be on the minion's skill list")
+		for _, gem in ipairs(build.skillsTab.socketGroupList[1].gemList) do
+			gem.skillMinionSkill = ilIndex
+			gem.skillMinionSkillCalcs = ilIndex
+		end
+		build.mainSocketGroup = 1
+		build.modFlag = true; build.buildFlag = true
+		for _ = 1, 6 do runCallback("OnFrame") end
+		return build.calcsTab.mainEnv
+	end
+
+	local function recalc()
+		build.configTab:BuildModList()
+		build.modFlag = true; build.buildFlag = true
+		for _ = 1, 4 do runCallback("OnFrame") end
+		return build.calcsTab.mainEnv
+	end
+
+	-- IL's "hit" is a pseudo-hit: it seeds the ignite but deals no damage of its own.
+	it("IL deals no hit damage (pseudo-hit) but still ignites", function()
+		local o = setupIL().minion.output
+		assert.are.equals(0, o.AverageDamage)
+		assert.are.equals(0, o.TotalDPS)
+		assert.True(o.IgniteDPS and o.IgniteDPS > 0, "IL should produce ignite DPS")
+	end)
+
+	-- IL ignite crits use a 50% base crit bonus (1.5x), not the minion's default 100% (2x).
+	it("IL uses a 50% base crit bonus (1.5x multiplier)", function()
+		assert.are.equals(1.5, setupIL().minion.output.PreEffectiveCritMultiplier)
+	end)
+
+	-- The minion's *increased* crit damage applies at half effectiveness for IL.
+	it("the minion's increased crit damage is half-effective for IL", function()
+		build.configTab.input.customMods = "Minions have 100% increased Critical Damage Bonus"
+		-- base 0.5 bonus, +100% increased applied at half (=+50%): 0.5 * (1 + 0.5) = 0.75 -> 1.75x.
+		-- (Full effectiveness would give 0.5 * 2.0 = 1.0 -> 2.0x.)
+		assert.are.equals(1.75, setupIL().minion.output.PreEffectiveCritMultiplier)
+	end)
+
+	-- "Minions have X% increased Magnitude of Ailments" scales IL's ignite end-to-end.
+	it("minion 'increased Magnitude of Ailments' scales IL ignite", function()
+		local base = setupIL().minion.output.IgniteDPS
+		assert.True(base and base > 0)
+		build.configTab.input.customMods = "Minions have 100% increased Magnitude of Ailments"
+		local scaled = recalc().minion.output.IgniteDPS
+		-- +100% magnitude roughly doubles the ignite (baseline magnitude increase is 0 here).
+		assert.True(math.abs(scaled - 2 * base) < 1e-6, string.format("expected %.6f, got %.6f", 2 * base, scaled))
+	end)
+
+	-- Full DPS runs offence on the IL skill an extra time. The half-effect that
+	-- preDamageFunc injects must not stack, or crit would over-halve.
+	it("IL crit/ignite stay correct under Full DPS (no double-applied halving)", function()
+		local base = setupIL().minion.output.IgniteDPS
+		build.skillsTab.socketGroupList[1].includeInFullDPS = true
+		local env = recalc()
+		assert.are.equals(1.5, env.minion.output.PreEffectiveCritMultiplier)
+		assert.True(math.abs(env.minion.output.IgniteDPS - base) < 1e-6,
+			string.format("ignite changed under Full DPS: %.6f vs %.6f", env.minion.output.IgniteDPS, base))
+	end)
+
+	-- The IL extra-skill result must live in the pass snapshot: a cached Full DPS
+	-- replay (item/tree comparison) has to keep the IL ignite, not silently drop it.
+	it("IL ignite survives a cached Full DPS replay", function()
+		local env = setupIL()
+		-- select a non-IL skill as the minion's main skill; IL stays granted as the
+		-- extra skill, so its ignite only enters Full DPS via the extra-skill pass
+		local otherIndex
+		for i, s in ipairs(env.minion.activeSkillList) do
+			local ge = s.activeEffect and s.activeEffect.grantedEffect
+			if not (ge and ge.id == "InfernalLegion") then otherIndex = i break end
+		end
+		assert.is_not_nil(otherIndex, "no non-IL minion skill found")
+		for _, gem in ipairs(build.skillsTab.socketGroupList[1].gemList) do
+			gem.skillMinionSkill = otherIndex
+			gem.skillMinionSkillCalcs = otherIndex
+		end
+		build.skillsTab.socketGroupList[1].includeInFullDPS = true
+		recalc()
+		local calcsModule = LoadModule("Modules/Calcs")
+		local store = { }
+		local fresh = calcsModule.calcFullDPS(build, "CALCULATOR", {}, { fullDPSCache = { store = store, capture = true } })
+		local performs = 0
+		local realPerform = calcsModule.perform
+		calcsModule.perform = function(...) performs = performs + 1 return realPerform(...) end
+		local cached = calcsModule.calcFullDPS(build, "CALCULATOR", {}, { fullDPSCache = { store = store } })
+		calcsModule.perform = realPerform
+		assert.are.equals(0, performs, "second call should replay from the cache")
+		assert.True(fresh.igniteDPS and fresh.igniteDPS > 0, "fresh pass should have the IL ignite")
+		assert.are.equals(fresh.igniteDPS, cached.igniteDPS)
+		assert.are.equals(fresh.TotalDotDPS, cached.TotalDotDPS)
+	end)
+
+	-- IL's hit is a pseudo-hit (no real damage), so a poison source must not seed a
+	-- poison off its big notional damage -- that was inflating Poison's evaluated value.
+	it("IL pseudo-hit does not seed poison from a poison source", function()
+		local igniteBefore = setupIL().minion.output.IgniteDPS
+		build.configTab.input.customMods = "Minions have 100% chance to Poison on Hit"
+		local env = recalc()
+		local poison = env.minion.output.PoisonDPS
+		assert.True(not poison or poison == 0, "IL pseudo-hit must not produce poison DPS")
+		assert.True(math.abs(env.minion.output.IgniteDPS - igniteBefore) < 1e-6, "ignite must be unchanged")
+	end)
+end)

src/Data/SkillStatMap.lua

@@ -642,6 +642,9 @@ return {
 ["active_skill_base_radius_+"] = {
 	skill("radiusExtra", nil),
 },
+["infernal_legion_minion_burning_effect_radius"] = {
+	skill("radius", nil),
+},
 ["base_skill_area_of_effect_+%"] = {
 	mod("AreaOfEffect", "INC", nil),
 },

src/Data/Skills/minion.lua

@@ -1132,6 +1132,58 @@ skills["MPSAncestralTotemSpiritSoulCasterProjectile"] = {
 				}
 			}
 
+			skills["InfernalLegion"] = {
+				name = "Infernal Legion",
+				hidden = true,
+				skillTypes = {
+					[SkillType.Damage] = true,
+					[SkillType.Area] = true,
+					[SkillType.Fire] = true,
+					[SkillType.CausesBurning] = true,
+				},
+				qualityStats = {
+				},
+				levels = {
+					[1] = { critChance = 0, levelRequirement = 0, }, -- only crits from enemy Critical Weakness
+				},
+				preDamageFunc = function(activeSkill, output)
+					local skillData = activeSkill.skillData
+					local sml = activeSkill.skillModList
+					local cfg = activeSkill.skillCfg
+					local base = output.Life * skillData.selfFireExplosionLifeMultiplier
+					skillData.FireBonusMin = base
+					skillData.FireBonusMax = base
+					-- minion's increased crit chance/damage are half-effective for IL
+					sml:NewMod("CritChance", "INC", -0.5 * sml:Sum("INC", cfg, "CritChance"), "Infernal Legion")
+					sml:NewMod("CritMultiplier", "INC", -0.5 * sml:Sum("INC", cfg, "CritMultiplier"), "Infernal Legion")
+				end,
+				statSets = {
+					[1] = {
+						label = "Infernal Legion",
+						incrementalEffectiveness = 0,
+						statDescriptionScope = "skill_stat_descriptions",
+						baseFlags = {
+							area = true,
+							fire = true,
+						},
+						baseMods = {
+							skill("selfFireExplosionLifeMultiplier", 0.01, { type = "Multiplier", var = "InfernalLegionBaseDamage" }),
+							skill("pseudoHitAilment", "Ignite"), -- fake hit: only seeds Ignite, no hit damage
+							skill("timeOverride", 1.25), -- fixed ~0.8/sec ignite cadence, not attack speed
+							mod("EnemyIgniteChance", "BASE", 100),
+							mod("CritMultiplier", "BASE", -50), -- 50% base crit bonus, not the minion's 100%
+						},
+						constantStats = {
+						},
+						stats = {
+						},
+						levels = {
+							[1] = { },
+						},
+					},
+				}
+			}
+
 skills["GAAnimateWeaponMaceSlam"] = {
 	name = "Mace Slam",
 	hidden = true,

src/Data/Skills/other.lua

@@ -3556,6 +3556,15 @@ skills["SupportCathasBrilliance"] = {
 			label = "Catha's Brilliance",
 			incrementalEffectiveness = 0.054999999701977,
 			statDescriptionScope = "gem_stat_descriptions",
+			statMap = {
+				-- Catha's Brilliance ignites enemies for a % of the minion's max life, the
+				-- same mechanic as Infernal Legion: wire the stat to the IL base-damage
+				-- multiplier and grant the companion the IL skill so the ignite is modelled.
+				["support_minions_ignite_for_%_max_life"] = {
+					mod("MinionModifier", "LIST", { mod = mod("Multiplier:InfernalLegionBaseDamage", "BASE", nil) }),
+					mod("ExtraMinionSkill", "LIST", { skillId = "InfernalLegion" }),
+				},
+			},
 			baseFlags = {
 			},
 			constantStats = {

src/Data/Skills/sup_str.lua

@@ -4634,9 +4634,8 @@ skills["SupportInfernalLegionPlayer"] = {
 					mod("MinionModifier", "LIST", { mod = mod("FireDegen", "BASE", nil, 0, 0, { type = "PerStat", stat = "Life" }, { type = "GlobalEffect", effectType = "Buff" }) }),
 					div = 6000,
 				},
-				["support_minion_instability_minion_base_fire_area_damage_per_minute"] = {
-					mod("MinionModifier", "LIST", { mod = mod("Multiplier:InfernalLegionBaseDamage", "BASE", nil, 0, 0, { type = "PercentStat", stat = "Life", percent = 1 }) }),
-					div = 60,
+				["support_minions_ignite_for_%_max_life"] = {
+					mod("MinionModifier", "LIST", { mod = mod("Multiplier:InfernalLegionBaseDamage", "BASE", nil) }),
 					mod("ExtraMinionSkill", "LIST", { skillId = "InfernalLegion" }),
 				},
 			},
@@ -4677,9 +4676,8 @@ skills["SupportInfernalLegionPlayerTwo"] = {
 					mod("MinionModifier", "LIST", { mod = mod("FireDegen", "BASE", nil, 0, 0, { type = "PerStat", stat = "Life" }, { type = "GlobalEffect", effectType = "Buff" }) }),
 					div = 6000,
 				},
-				["support_minion_instability_minion_base_fire_area_damage_per_minute"] = {
-					mod("MinionModifier", "LIST", { mod = mod("Multiplier:InfernalLegionBaseDamage", "BASE", nil, 0, 0, { type = "PercentStat", stat = "Life", percent = 1 }) }),
-					div = 60,
+				["support_minions_ignite_for_%_max_life"] = {
+					mod("MinionModifier", "LIST", { mod = mod("Multiplier:InfernalLegionBaseDamage", "BASE", nil) }),
 					mod("ExtraMinionSkill", "LIST", { skillId = "InfernalLegion" }),
 				},
 			},
@@ -4722,9 +4720,8 @@ skills["SupportInfernalLegionPlayerThree"] = {
 					mod("MinionModifier", "LIST", { mod = mod("FireDegen", "BASE", nil, 0, 0, { type = "PerStat", stat = "Life" }, { type = "GlobalEffect", effectType = "Buff" }) }),
 					div = 6000,
 				},
-				["support_minion_instability_minion_base_fire_area_damage_per_minute"] = {
-					mod("MinionModifier", "LIST", { mod = mod("Multiplier:InfernalLegionBaseDamage", "BASE", nil, 0, 0, { type = "PercentStat", stat = "Life", percent = 1 }) }),
-					div = 60,
+				["support_minions_ignite_for_%_max_life"] = {
+					mod("MinionModifier", "LIST", { mod = mod("Multiplier:InfernalLegionBaseDamage", "BASE", nil) }),
 					mod("ExtraMinionSkill", "LIST", { skillId = "InfernalLegion" }),
 				},
 			},

src/Export/Skills/minion.txt

@@ -164,6 +164,58 @@ skills["MinionInstability"] = {
 	}
 }
 
+skills["InfernalLegion"] = {
+	name = "Infernal Legion",
+	hidden = true,
+	skillTypes = {
+		[SkillType.Damage] = true,
+		[SkillType.Area] = true,
+		[SkillType.Fire] = true,
+		[SkillType.CausesBurning] = true,
+	},
+	qualityStats = {
+	},
+	levels = {
+		[1] = { critChance = 0, levelRequirement = 0, }, -- only crits from enemy Critical Weakness
+	},
+	preDamageFunc = function(activeSkill, output)
+		local skillData = activeSkill.skillData
+		local sml = activeSkill.skillModList
+		local cfg = activeSkill.skillCfg
+		local base = output.Life * skillData.selfFireExplosionLifeMultiplier
+		skillData.FireBonusMin = base
+		skillData.FireBonusMax = base
+		-- minion's increased crit chance/damage are half-effective for IL
+		sml:NewMod("CritChance", "INC", -0.5 * sml:Sum("INC", cfg, "CritChance"), "Infernal Legion")
+		sml:NewMod("CritMultiplier", "INC", -0.5 * sml:Sum("INC", cfg, "CritMultiplier"), "Infernal Legion")
+	end,
+	statSets = {
+		[1] = {
+			label = "Infernal Legion",
+			incrementalEffectiveness = 0,
+			statDescriptionScope = "skill_stat_descriptions",
+			baseFlags = {
+				area = true,
+				fire = true,
+			},
+			baseMods = {
+				skill("selfFireExplosionLifeMultiplier", 0.01, { type = "Multiplier", var = "InfernalLegionBaseDamage" }),
+				skill("pseudoHitAilment", "Ignite"), -- fake hit: only seeds Ignite, no hit damage
+				skill("timeOverride", 1.25), -- fixed ~0.8/sec ignite cadence, not attack speed
+				mod("EnemyIgniteChance", "BASE", 100),
+				mod("CritMultiplier", "BASE", -50), -- 50% base crit bonus, not the minion's 100%
+			},
+			constantStats = {
+			},
+			stats = {
+			},
+			levels = {
+				[1] = { },
+			},
+		},
+	}
+}
+
 #addSkillTypes Melee MeleeSingleTarget Area
 #skill GAAnimateWeaponMaceSlam Mace Slam
 #set GAAnimateWeaponMaceSlam

src/Export/Skills/other.txt

@@ -241,6 +241,15 @@ statMap = {
 
 #skill SupportCathasBrilliance
 #set SupportCathasBrilliance
+statMap = {
+	-- Catha's Brilliance ignites enemies for a % of the minion's max life, the
+	-- same mechanic as Infernal Legion: wire the stat to the IL base-damage
+	-- multiplier and grant the companion the IL skill so the ignite is modelled.
+	["support_minions_ignite_for_%_max_life"] = {
+		mod("MinionModifier", "LIST", { mod = mod("Multiplier:InfernalLegionBaseDamage", "BASE", nil) }),
+		mod("ExtraMinionSkill", "LIST", { skillId = "InfernalLegion" }),
+	},
+},
 #mods
 #skillEnd