refactor: sync 2.0.4

benchmarks/mapped.luau

@@ -4,8 +4,7 @@ local bench = require("./bench")
 local atom = Charm.atom
 local computed = Charm.computed
 local mapped = Charm.mapped
-local pauseTracking = Charm.signals.pauseTracking
-local resumeTracking = Charm.signals.resumeTracking
+local setCurrentSub = Charm.signals.setCurrentSub
 
 type Entry = { number }
 
@@ -26,9 +25,9 @@ local function simpleMapped(source: () -> { Entry }, mapper: (Entry, number) ->
 		local nextState = {}
 
 		for index, value in state do
-			pauseTracking()
+			local prevSub = setCurrentSub(nil)
 			local success, valueOut, keyOut = pcall(mapper, value, index)
-			resumeTracking()
+			setCurrentSub(prevSub)
 
 			if success then
 				nextState[keyOut] = valueOut

pkgs/charm-sync/tests/spec.luau

@@ -10,10 +10,12 @@ local function spec(name: string)
 	end)
 end
 
-spec("client")
-spec("server")
-spec("flatten")
-spec("patch")
-spec("validate")
+describe("charm-sync", function()
+	spec("client")
+	spec("server")
+	spec("flatten")
+	spec("patch")
+	spec("validate")
+end)
 
 return {}

pkgs/charm/src/listen.luau

@@ -1,8 +1,7 @@
 local signals = require("./signals")
 
 local effect = signals.effect
-local pauseTracking = signals.pauseTracking
-local resumeTracking = signals.resumeTracking
+local setCurrentSub = signals.setCurrentSub
 
 local function listen<T>(selector: () -> T, listener: (state: T, previous: T?, dispose: () -> ()) -> ()): () -> ()
 	local disposeImmediately = false
@@ -17,9 +16,9 @@ local function listen<T>(selector: () -> T, listener: (state: T, previous: T?, d
 		current = selector()
 
 		if current ~= previous then
-			pauseTracking()
+			local prevSub = setCurrentSub(nil)
 			local success, result: unknown = pcall(listener, current, previous, dispose)
-			resumeTracking()
+			setCurrentSub(prevSub)
 
 			if not success then
 				error(`listen() encountered an error: {result}`)

pkgs/charm/src/mapped.luau

@@ -1,10 +1,7 @@
---!optimize 2
-
 local signals = require("./signals")
 
 local computed = signals.computed
-local pauseTracking = signals.pauseTracking
-local resumeTracking = signals.resumeTracking
+local setCurrentSub = signals.setCurrentSub
 
 type Mapped =
 	& (<KI, VI, KO, VO>(selector: () -> { [KI]: VI }, mapper: (item: VI, key: KI) -> (VO, KO)) -> () -> { [KO]: VO })
@@ -19,9 +16,9 @@ local function mapped<KI, VI, KO, VO>(selector: () -> { [KI]: VI }, mapper: (ite
 	local keyCache: { [KI]: KO } = {}
 
 	local function map(value: VI, key: KI): (VO, KO)
-		pauseTracking()
+		local prevSub = setCurrentSub(nil)
 		local success, valueOut, keyOut = pcall(mapper, value, key)
-		resumeTracking()
+		setCurrentSub(prevSub)
 
 		if not success then
 			error(`mapped() transform function failed: {valueOut}`)

pkgs/charm/src/observe.luau

@@ -3,10 +3,9 @@ local signals = require("./signals")
 local effect = signals.effect
 local effectScope = signals.effectScope
 local getCurrentSub = signals.getCurrentSub
+local setCurrentSub = signals.setCurrentSub
 local onEffectCleanup = signals.onEffectCleanup
 local onScopeDispose = signals.onScopeDispose
-local pauseTracking = signals.pauseTracking
-local resumeTracking = signals.resumeTracking
 
 type Cleanup = () -> ()
 
@@ -47,9 +46,9 @@ local function observe<K, V>(selector: () -> { [K]: V }, observer: (item: V, key
 		currentItems = selector()
 
 		if currentItems ~= previousItems then
-			pauseTracking()
+			local prevSub = setCurrentSub(nil)
 			local success, result: unknown = pcall(updateScopes, currentItems, previousItems)
-			resumeTracking()
+			setCurrentSub(prevSub)
 
 			if not success then
 				error(`observe() encountered an error: {result}`, 2)

pkgs/charm/src/signals.luau

@@ -62,8 +62,7 @@ type Signal<T = any> = ReactiveNode & {
 }
 
 local pauseStack: { ReactiveNode? } = {}
-local pauseStackCount = 0
-local queuedEffects: { Effect | EffectScope } = {}
+local queuedEffects: { Effect | EffectScope? } = {}
 
 local link: (dep: ReactiveNode, sub: ReactiveNode) -> ()
 local unlink: (link: Link, sub: ReactiveNode?) -> Link?
@@ -193,16 +192,16 @@ local function endBatch()
 	end
 end
 
+--- @deprecated Will be removed in the next major version. Use
+--- `const pausedSub = setCurrentSub(undefined)` instead for better performance.
 local function pauseTracking()
-	pauseStackCount += 1
-	pauseStack[pauseStackCount] = activeSub
-	activeSub = nil
+	table.insert(pauseStack, setCurrentSub(nil))
 end
 
+--- @deprecated Will be removed in the next major version. Use
+--- `setCurrentSub(pausedSub)` instead for better performance.
 local function resumeTracking()
-	activeSub = pauseStack[pauseStackCount]
-	pauseStack[pauseStackCount] = nil
-	pauseStackCount -= 1
+	setCurrentSub(table.remove(pauseStack))
 end
 
 local function updateComputed(c: Computed): boolean
@@ -311,9 +310,8 @@ local function effectStop(this: Effect | EffectScope): () -> ()
 			dep = unlink(dep, this)
 		end
 		local sub = this.subs
-		while sub do
+		if sub then
 			unlink(sub)
-			sub = this.subs
 		end
 		(this :: Effect).flags = NONE
 		cleanupEffect(this)
@@ -361,9 +359,11 @@ local function effectScope(fn: () -> (), detached: boolean?): () -> ()
 	if activeScope and not detached then
 		link(e, activeScope)
 	end
-	local prev = setCurrentScope(e)
+	local prevSub = setCurrentSub(nil)
+	local prevScope = setCurrentScope(e)
 	local success, result: unknown = pcall(fn)
-	setCurrentScope(prev)
+	setCurrentScope(prevScope)
+	setCurrentSub(prevSub)
 	if not success then
 		error(result)
 	end
@@ -392,15 +392,18 @@ local function notify(e: Effect | EffectScope)
 	end
 end
 
-local function unwatched(signal: Signal | Effect | Computed)
-	local toRemove = signal.deps
-	if toRemove then
-		repeat
-			toRemove = unlink(toRemove, signal)
-		until toRemove == nil
-		(signal :: Signal).flags = bit32.bor(signal.flags, DIRTY)
+local function unwatched(node: Signal | Computed | Effect | EffectScope)
+	if (node :: Computed).getter then
+		local toRemove = node.deps
+		if toRemove then
+			(node :: Computed).flags = bit32.bor(MUTABLE, DIRTY)
+			repeat
+				toRemove = unlink(toRemove, node)
+			until not toRemove
+		end
+	elseif (node :: Signal).previousValue == nil then
+		effectStop(node :: Effect)()
 	end
-	cleanupEffect(signal :: Effect)
 end
 
 local reactiveSystem = createReactiveSystem({

pkgs/charm/src/subscribe.luau

@@ -1,8 +1,7 @@
 local signals = require("./signals")
 
 local effect = signals.effect
-local pauseTracking = signals.pauseTracking
-local resumeTracking = signals.resumeTracking
+local setCurrentSub = signals.setCurrentSub
 
 local function subscribe<T>(selector: () -> T, listener: (state: T, lastState: T) -> ()): () -> ()
 	local current: T
@@ -15,9 +14,9 @@ local function subscribe<T>(selector: () -> T, listener: (state: T, lastState: T
 		if mounted then
 			mounted = false
 		elseif current ~= previous then
-			pauseTracking()
+			local prevSub = setCurrentSub(nil)
 			local success, result: unknown = pcall(listener, current, previous)
-			resumeTracking()
+			setCurrentSub(prevSub)
 
 			if not success then
 				error(`subscribe() encountered an error: {result}`)

pkgs/charm/src/untracked.luau

@@ -1,12 +1,11 @@
 local signals = require("./signals")
 
-local pauseTracking = signals.pauseTracking
-local resumeTracking = signals.resumeTracking
+local setCurrentSub = signals.setCurrentSub
 
 local function untracked<T, Args...>(callback: ((Args...) -> T) | (Args...) -> (), ...: Args...): T
-	pauseTracking()
+	local prevSub = setCurrentSub(nil)
 	local success, result = pcall(callback, ...)
-	resumeTracking()
+	setCurrentSub(prevSub)
 
 	if not success then
 		error(result)

pkgs/charm/tests/signals/effect.spec.luau

@@ -303,9 +303,14 @@ end)
 test("should run inner effect cleanup", function()
 	local cleanups = 0
 
-	local a, setA = signal(false)
+	local src, setSrc = signal(false)
 	local stopEffect = effect(function()
-		a()
+		src()
+		effect(function()
+			onEffectCleanup(function()
+				cleanups += 1
+			end)
+		end)
 		effect(function()
 			onEffectCleanup(function()
 				cleanups += 1
@@ -314,12 +319,12 @@ test("should run inner effect cleanup", function()
 	end)
 
 	assert(cleanups == 0, "should not cleanup immediately")
-	setA(true)
-	assert(cleanups == 1, "should cleanup after outer update")
+	setSrc(true)
+	assert(cleanups == 2, "should cleanup after outer update")
 	stopEffect()
-	assert(cleanups == 2, "should cleanup after outer dispose")
-	setA(false)
-	assert(cleanups == 2, "should not cleanup after update")
+	assert(cleanups == 4, "should cleanup after outer dispose")
+	setSrc(false)
+	assert(cleanups == 4, "should not cleanup after update")
 end)
 
 return {}

pkgs/charm/tests/signals/gc.spec.luau

@@ -0,0 +1,72 @@
+local Charm = require("@pkgs/charm/src/lib")
+local suite = require("@tests/suite")
+
+local atom = Charm.atom
+local computed = Charm.computed
+local effect = Charm.effect
+local effectScope = Charm.effectScope
+local test = suite.test
+
+--- Creates a weak reference to a value.
+--- @return Function to dereference the value.
+local function weakRef<T>(value: T): () -> T?
+	local ref = setmetatable({ value = value }, { __mode = "v" })
+	return function()
+		return ref.value
+	end
+end
+
+--- Triggers garbage collection by allocating excessive memory.
+local function gc()
+	for _ = 1, 1000 do
+		local _ = table.create(100, 0)
+	end
+end
+
+--- In alien-signals, a computed value unlinks from dependencies when its last
+--- parent scope is disposed. Calling a computed value outside of a scope links
+--- it to dependencies, but the dependencies hold strong references to the
+--- computed value, so it won't GC until called in a scope and disposed.
+---
+--- This function releases a computed value by linking it to a scope and then
+--- immediately closing it, causing alien-signals to unlink the computed value
+--- and allow it to be garbage collected.
+local function release(getter: () -> ())
+	effectScope(function()
+		getter()
+	end)()
+end
+
+test("should release computed cache", function()
+	local srcRef = weakRef({})
+	local src = atom(srcRef())
+
+	local c = computed(function()
+		return src()
+	end)
+
+	c() -- cache src value
+	src(nil) -- release value
+	c = release(c) -- release computed
+
+	gc()
+	assert(srcRef() == nil, "should release computed cache")
+end)
+
+test("should not release effect for atom", function()
+	local effectCalls = 0
+	local src = atom(0)
+
+	effect(function()
+		effectCalls += 1
+		src()
+	end)
+
+	assert(effectCalls == 1, "should call effect once")
+
+	gc()
+	src(src() + 1)
+	assert(effectCalls == 2, "should call effect again")
+end)
+
+return {}

pkgs/charm/tests/signals/spec.luau

@@ -8,11 +8,14 @@ local function spec(name: string)
 	end)
 end
 
-spec("computed")
-spec("effect")
-spec("effectScope")
-spec("issue_48")
-spec("topology")
-spec("untrack")
+describe("signals", function()
+	spec("computed")
+	spec("effect")
+	spec("effectScope")
+	spec("issue_48")
+	spec("gc")
+	spec("topology")
+	spec("untrack")
+end)
 
 return {}

pkgs/charm/tests/spec.luau

@@ -2,19 +2,14 @@ local suite = require("@tests/suite")
 
 local describe = suite.describe
 
-local function collect(name: string)
-	describe(name, function()
-		return require(`./{name}/spec`) :: any
-	end)
-end
-
 local function spec(name: string)
 	describe(name, function()
 		return require(`./{name}.spec`) :: any
 	end)
 end
 
-collect("signals")
+require("./signals/spec")
+
 spec("gc")
 spec("listen")
 spec("mapped")

pkgs/react-charm/tests/spec.luau

@@ -10,6 +10,8 @@ local function spec(name: string)
 	end)
 end
 
-spec("useAtom")
+describe("react-charm", function()
+	spec("useAtom")
+end)
 
 return {}

pkgs/vide-charm/tests/spec.luau

@@ -10,6 +10,8 @@ local function spec(name: string)
 	end)
 end
 
-spec("useAtom")
+describe("vide-charm", function()
+	spec("useAtom")
+end)
 
 return {}

tests/spec.server.luau

@@ -1,6 +1,5 @@
 local suite = require("./suite")
 
-local describe = suite.describe
 local finish = suite.finish
 
 if not script then
@@ -9,16 +8,8 @@ end
 
 _G.__DEV__ = true
 
-describe("charm-sync", function()
-	require(script.Parent.CharmSync.spec)
-end)
-
-describe("react-charm", function()
-	require(script.Parent.ReactCharm.spec)
-end)
-
-describe("vide-charm", function()
-	require(script.Parent.VideCharm.spec)
-end)
+require(script.Parent.CharmSync.spec)
+require(script.Parent.ReactCharm.spec)
+require(script.Parent.VideCharm.spec)
 
 finish()