Add aftershock chance for Slam skills and model Earthquake's Aftershock

spec/System/TestAftershock_spec.lua

@@ -0,0 +1,87 @@
+describe("TestAftershock", function()
+	before_each(function()
+		newBuild()
+	end)
+
+	teardown(function()
+		-- newBuild() takes care of resetting everything in setup()
+	end)
+
+	local function setupSkill(weaponBase, gemLine, customMods)
+		if weaponBase then
+			build.itemsTab:CreateDisplayItemFromRaw("New Item\n" .. weaponBase)
+			build.itemsTab:AddDisplayItem()
+		end
+		build.skillsTab:PasteSocketGroup(gemLine)
+		build.mainSocketGroup = 1
+		build.configTab.input.customMods = customMods or ""
+		build.configTab:BuildModList()
+		runCallback("OnFrame")
+		return build.calcsTab.mainOutput
+	end
+
+	local function assertClose(expected, actual)
+		assert.is_true(math.abs(expected - actual) < 0.001, string.format("expected %s, got %s", tostring(expected), tostring(actual)))
+	end
+
+	it("Earthbreaker gives slam skills a chance to cause an additional aftershock, scaling DPS but not average hit", function()
+		local base = setupSkill("Wooden Club", "Leap Slam 20/0  1")
+		local baseDPS, baseAvg = base.TotalDPS, base.AverageDamage
+		assert.is_true(baseDPS > 0)
+		assert.are.equals(0, base.AftershockChance)
+
+		newBuild()
+		local out = setupSkill("Wooden Club", "Leap Slam 20/0  1", "25% chance for Slam Skills you use yourself to cause an additional Aftershock")
+		assert.are.equals(25, out.AftershockChance)
+		assertClose(baseDPS * 1.25, out.TotalDPS)
+		assertClose(baseAvg, out.AverageDamage)
+	end)
+
+	it("does not give non-slam skills an aftershock chance", function()
+		local out = setupSkill("Wooden Club", "Perfect Strike 20/0  1", "25% chance for Slam Skills you use yourself to cause an additional Aftershock")
+		assert.is_true(out.TotalDPS > 0)
+		assert.is_nil(out.AftershockChance)
+	end)
+
+	it("stacks aftershock chance from passives and support gems without a cap", function()
+		local base = setupSkill("Wooden Club", "Leap Slam 20/0  1")
+		local baseDPS = base.TotalDPS
+
+		newBuild()
+		local out = setupSkill("Wooden Club", "Leap Slam 20/0  1", [[
+		25% chance for Slam Skills you use yourself to cause an additional Aftershock
+		10% chance for Mace Slam Skills you use yourself to cause an additional Aftershock
+		5% chance for Slam Skills to cause an additional Aftershock
+		]])
+		assert.are.equals(40, out.AftershockChance)
+
+		newBuild()
+		out = setupSkill("Wooden Club", "Leap Slam 20/0  1\nAftershock II 20/0  1", "80% chance for Slam Skills you use yourself to cause an additional Aftershock")
+		assert.are.equals(115, out.AftershockChance)
+		assertClose(baseDPS * 2.15, out.TotalDPS)
+	end)
+
+	it("only applies mace slam aftershock chance when attacking with a mace", function()
+		local out = setupSkill("Hardwood Spear", "Thunderous Leap 20/0  1", "10% chance for Mace Slam Skills you use yourself to cause an additional Aftershock")
+		assert.is_true(out.TotalDPS > 0)
+		assert.are.equals(0, out.AftershockChance)
+
+		newBuild()
+		out = setupSkill("Hardwood Spear", "Thunderous Leap 20/0  1", "25% chance for Slam Skills you use yourself to cause an additional Aftershock")
+		assert.are.equals(25, out.AftershockChance)
+
+		newBuild()
+		out = setupSkill("Wooden Club", "Leap Slam 20/0  1", "10% chance for Mace Slam Skills you use yourself to cause an additional Aftershock")
+		assert.are.equals(10, out.AftershockChance)
+	end)
+
+	it("only applies shapeshift slam aftershock chance to shapeshift slams", function()
+		local out = setupSkill("Changeling Talisman", "Rampage 20/0  1", "15% chance for Shapeshift Slam Skills you use yourself to cause an additional Aftershock")
+		assert.is_true(out.TotalDPS > 0)
+		assert.are.equals(15, out.AftershockChance)
+
+		newBuild()
+		out = setupSkill("Wooden Club", "Leap Slam 20/0  1", "15% chance for Shapeshift Slam Skills you use yourself to cause an additional Aftershock")
+		assert.are.equals(0, out.AftershockChance)
+	end)
+end)

spec/System/TestEarthquake_spec.lua

@@ -0,0 +1,141 @@
+describe("TestEarthquake", function()
+	before_each(function()
+		newBuild()
+	end)
+
+	teardown(function()
+		-- newBuild() takes care of resetting everything in setup()
+	end)
+
+	-- statSetIndex 1 = Impact, 2 = Aftershock
+	local function setupEarthquake(statSetIndex, customMods, weapons)
+		for _, weapon in ipairs(weapons or { "Wooden Club" }) do
+			build.itemsTab:CreateDisplayItemFromRaw("New Item\n" .. weapon)
+			build.itemsTab:AddDisplayItem()
+		end
+		build.skillsTab:PasteSocketGroup("Earthquake 20/0  1")
+		local gemInstance = build.skillsTab.socketGroupList[1].gemList[1]
+		gemInstance.statSet = { EarthquakePlayer = statSetIndex }
+		gemInstance.statSetCalcs = { EarthquakePlayer = statSetIndex }
+		build.mainSocketGroup = 1
+		build.configTab.input.customMods = customMods or ""
+		build.configTab:BuildModList()
+		runCallback("OnFrame")
+		return build.calcsTab.mainOutput
+	end
+
+	local function assertClose(expected, actual)
+		assert.is_true(math.abs(expected - actual) < 0.001, string.format("expected %s, got %s", tostring(expected), tostring(actual)))
+	end
+
+	-- Jagged Ground cannot be created on top of an existing patch: an attack that lands before the previous patch
+	-- erupts creates nothing, so the next patch (and its Aftershock) comes from the first attack at or after the eruption
+	local function expectedHitTime(out)
+		local attackTime = 1 / out.Speed
+		return attackTime * math.max(math.ceil(out.Duration / attackTime - 1e-9), 1)
+	end
+
+	it("fires the Aftershock on every Nth attack, N being the attack times needed to cover the patch duration", function()
+		local out = setupEarthquake(2)
+		assert.is_true(out.Duration > 0)
+		assert.is_true(out.Speed > 1 / out.Duration, "test assumes attack time is shorter than the patch duration")
+		assertClose(expectedHitTime(out), out.HitTime)
+		assertClose(1 / out.HitTime, out.HitSpeed)
+		assert.is_true(out.HitTime >= out.Duration - 0.001, "no patch can be created before the previous one erupts")
+		assert.is_true(out.HitTime - 1 / out.Speed < out.Duration, "the first attack after the eruption creates the next patch")
+		assertClose(out.AverageDamage * out.HitSpeed * out.DpsMultiplier, out.TotalDPS)
+		assert.is_falsy(build.calcsTab.mainEnv.player.mainSkill.skillData.showAverage)
+	end)
+
+	it("rounds the Aftershock time up to a whole number of attacks for any patch duration", function()
+		for _, reduced in ipairs({ 30, 50, 70, 80, 90 }) do
+			newBuild()
+			local out = setupEarthquake(2, reduced .. "% reduced Skill Effect Duration")
+			assertClose(expectedHitTime(out), out.HitTime)
+			assertClose(out.AverageDamage / out.HitTime * out.DpsMultiplier, out.TotalDPS)
+		end
+	end)
+
+	it("wastes every other attack when the patch outlasts the attack time", function()
+		local base = setupEarthquake(2)
+		local attackTime = 1 / base.Speed
+		-- shorten the patch to 1.5 attack times: the second attack lands on the live patch and creates nothing
+		local reduced = math.floor(100 * (1 - 1.5 * attackTime / base.Duration))
+		newBuild()
+		local out = setupEarthquake(2, reduced .. "% reduced Skill Effect Duration")
+		assert.is_true(out.Duration > attackTime and out.Duration < 2 * attackTime, "test assumes the patch lasts between one and two attack times")
+		assertClose(2 * attackTime, out.HitTime)
+		assertClose(base.Speed / 2, out.HitSpeed)
+	end)
+
+	it("lowers Aftershock DPS when attacking slightly faster than the patch duration", function()
+		local base = setupEarthquake(2)
+		local attackTime = 1 / base.Speed
+		-- patch just shorter than the attack time: every attack creates a patch
+		local reduced = math.ceil(100 * (1 - 0.95 * attackTime / base.Duration))
+		newBuild()
+		local slow = setupEarthquake(2, reduced .. "% reduced Skill Effect Duration")
+		assert.is_true(slow.Duration <= 1 / slow.Speed, "test assumes the patch erupts before the next attack")
+		assertClose(slow.Speed, slow.HitSpeed)
+		-- 10% more attack speed makes the next attack land on the live patch, halving the Aftershock rate
+		newBuild()
+		local fast = setupEarthquake(2, reduced .. "% reduced Skill Effect Duration\n10% increased Attack Speed")
+		assert.is_true(fast.Speed > slow.Speed)
+		assert.is_true(fast.Duration > 1 / fast.Speed, "test assumes the next attack now lands before the eruption")
+		assertClose(fast.Speed / 2, fast.HitSpeed)
+		assert.is_true(fast.TotalDPS < slow.TotalDPS)
+	end)
+
+	it("uses the attack rate for Aftershock once the patch duration is shorter than the attack time", function()
+		local out = setupEarthquake(2, "80% reduced Skill Effect Duration")
+		assert.is_true(out.Speed < 1 / out.Duration, "test assumes attack time is longer than the patch duration")
+		assertClose(out.Speed, out.HitSpeed)
+		assertClose(out.AverageDamage * out.Speed * out.DpsMultiplier, out.TotalDPS)
+
+		newBuild()
+		out = setupEarthquake(2, "100% reduced Skill Effect Duration\n200% increased Attack Speed")
+		assert.are.equals(0, out.Duration)
+		assertClose(out.AverageDamage * out.Speed * out.DpsMultiplier, out.TotalDPS)
+	end)
+
+	it("rounds the Aftershock time using the combined attack time when dual wielding", function()
+		local weapons = { "Marauding Mace\n20% increased Attack Speed", "Marauding Mace" }
+		local out = setupEarthquake(2, nil, weapons)
+		assert.is_true(out.MainHand.Speed ~= out.OffHand.Speed, "test assumes the two weapons attack at different speeds")
+		assertClose(expectedHitTime(out), out.HitTime)
+		assertClose(out.AverageDamage * out.HitSpeed * out.DpsMultiplier, out.TotalDPS)
+
+		newBuild()
+		out = setupEarthquake(2, "85% reduced Skill Effect Duration", weapons)
+		assert.is_true(out.Speed < 1 / out.Duration, "test assumes the combined attack time is longer than the patch duration")
+		assert.is_true(out.Speed ~= out.MainHand.Speed, "test assumes the combined attack rate differs from the main hand rate")
+		assertClose(out.Speed, out.HitSpeed)
+		assertClose(out.AverageDamage * out.Speed * out.DpsMultiplier, out.TotalDPS)
+	end)
+
+	it("applies additional aftershock chance to the Aftershock but not to the Impact", function()
+		local aftershockMod = "25% chance for Slam Skills you use yourself to cause an additional Aftershock"
+		local base = setupEarthquake(1)
+		newBuild()
+		local out = setupEarthquake(1, aftershockMod)
+		assert.is_falsy(out.AftershockChance and out.AftershockChance > 0)
+		assertClose(base.TotalDPS, out.TotalDPS)
+
+		newBuild()
+		base = setupEarthquake(2)
+		newBuild()
+		out = setupEarthquake(2, aftershockMod)
+		assert.are.equals(25, out.AftershockChance)
+		assertClose(base.TotalDPS * 1.25, out.TotalDPS)
+	end)
+
+	it("does not cap the Impact hit rate", function()
+		local base = setupEarthquake(1)
+		assert.is_nil(base.HitSpeed)
+
+		newBuild()
+		local out = setupEarthquake(1, "200% increased Attack Speed")
+		assert.is_nil(out.HitSpeed)
+		assertClose(base.TotalDPS * out.Speed / base.Speed, out.TotalDPS)
+	end)
+end)