feat: allow conditional dependencies (#4)

* feat: allow conditional dependencies

* docs: remove conditional deps warnings

* fix: allow nested captures

* docs: add dev flag

* fix: `try()` uses pcall if passed `finally()`

* docs: interval is optional

* docs: update readme

* docs: add client/server tags

src/__tests__/benchmarks/atom.bench.luau

@@ -7,34 +7,23 @@ local atom = require(Package.atom)
 local computed = require(Package.computed)
 
 local function parameterGenerator()
-	return atom({ count = 0 })
+	return atom(0)
 end
 
 local benchmarks = {
 	atom = function(_, source: any)
 		for _ = 1, 500 do
-			source({ count = math.random(1, 2) })
+			source(math.random(1, 2))
 		end
 	end,
 
 	computed = function(_, source: any)
 		computed(function()
-			return { count = 2 * source().count }
+			return 2 * source()
 		end)
-		for _ = 1, 500 do
-			source({ count = math.random(1, 2) })
-		end
-	end,
 
-	computed_nested = function(_, source: any)
-		local double = computed(function()
-			return { count = 2 * source().count }
-		end)
-		computed(function()
-			return { count = 2 * double().count }
-		end)
 		for _ = 1, 500 do
-			source({ count = math.random(1, 2) })
+			source(math.random(1, 2))
 		end
 	end,
 }

src/__tests__/capture.spec.luau

@@ -2,21 +2,47 @@ local atom = require(script.Parent.Parent.atom)
 local store = require(script.Parent.Parent.store)
 
 return function()
+	it("gracefully handles yielding", function()
+		expect(function()
+			store.capture(function()
+				task.wait(10)
+				return 1
+			end)
+		end).to.throw()
+	end)
+
 	it("captures atoms from a function", function()
 		local a, b, c = atom(1), atom(1), atom(2)
-		local captured, result = store.capture(function()
+		local deps, result = store.capture(function()
 			return a() + b()
 		end)
-		expect(captured[a]).to.be.ok()
-		expect(captured[b]).to.be.ok()
-		expect(captured[c]).to.never.be.ok()
+		expect(deps[a]).to.be.ok()
+		expect(deps[b]).to.be.ok()
+		expect(deps[c]).to.never.be.ok()
 		expect(result).to.equal(2)
 	end)
 
 	it("captures an atom by itself", function()
 		local a = atom(1)
-		local captured, result = store.capture(a)
-		expect(captured[a]).to.be.ok()
+		local deps, result = store.capture(a)
+		expect(deps[a]).to.be.ok()
 		expect(result).to.equal(1)
 	end)
+
+	it("allows nested captures", function()
+		local a = atom(1)
+		local b = atom(1)
+		local inner
+		local outer = store.capture(function()
+			inner = store.capture(function()
+				return b()
+			end)
+			return a()
+		end)
+
+		assert(outer[a], "outer did not capture a")
+		assert(outer[b], "outer did not capture b")
+		assert(inner[a] == nil, "inner captured a")
+		assert(inner[b], "inner did not capture b")
+	end)
 end

src/__tests__/computed.spec.luau

@@ -68,4 +68,35 @@ return function()
 
 		assert(count(store.listeners[source]) == 0, "nested computed atom did not gc")
 	end)
+
+	it("tracks conditional dependencies", function()
+		local condition = atom(false)
+		local a = atom(0)
+		local b = atom(1)
+		local reruns = 0
+		local current
+
+		-- assign variable to avoid gc
+		local _ = computed(function()
+			reruns += 1
+			current = if condition() then a() else b()
+			return current
+		end)
+
+		expect(reruns).to.equal(1)
+		expect(current).to.equal(1)
+
+		condition(true)
+		expect(reruns).to.equal(2)
+		expect(current).to.equal(0)
+
+		a(1)
+		b(2)
+		expect(reruns).to.equal(3)
+		expect(current).to.equal(1)
+
+		condition(false)
+		expect(reruns).to.equal(4)
+		expect(current).to.equal(2)
+	end)
 end

src/__tests__/effect.spec.luau

@@ -43,4 +43,33 @@ return function()
 		unsubscribe()
 		expect(cleanups).to.equal(2)
 	end)
+
+	it("tracks conditional dependencies", function()
+		local condition = atom(false)
+		local a = atom(0)
+		local b = atom(1)
+		local reruns = 0
+		local current
+
+		effect(function()
+			reruns += 1
+			current = if condition() then a() else b()
+		end)
+
+		expect(reruns).to.equal(1)
+		expect(current).to.equal(1)
+
+		condition(true)
+		expect(reruns).to.equal(2)
+		expect(current).to.equal(0)
+
+		a(1)
+		b(2)
+		expect(reruns).to.equal(3)
+		expect(current).to.equal(1)
+
+		condition(false)
+		expect(reruns).to.equal(4)
+		expect(current).to.equal(2)
+	end)
 end

src/__tests__/peek.spec.luau

@@ -4,12 +4,12 @@ local store = require(script.Parent.Parent.store)
 return function()
 	it("calls an atom without capturing it", function()
 		local a, b, c = atom(1), atom(1), atom(1)
-		local captured, result = store.capture(function()
+		local deps, result = store.capture(function()
 			return a() + store.peek(b) + c()
 		end)
-		expect(captured[a]).to.be.ok()
-		expect(captured[b]).to.never.be.ok()
-		expect(captured[c]).to.be.ok()
+		expect(deps[a]).to.be.ok()
+		expect(deps[b]).to.never.be.ok()
+		expect(deps[c]).to.be.ok()
 		expect(result).to.equal(3)
 	end)
 

src/__tests__/subscribe.spec.luau

@@ -67,4 +67,32 @@ return function()
 
 		assert(count(store.listeners[source]) == 0, "computed atom did not collect")
 	end)
+
+	it("tracks conditional dependencies", function()
+		local condition = atom(false)
+		local a = atom(0)
+		local b = atom(1)
+		local reruns = 0
+		local current
+
+		subscribe(function()
+			return if condition() then a() else b()
+		end, function(state)
+			reruns += 1
+			current = state
+		end)
+
+		condition(true)
+		expect(reruns).to.equal(1)
+		expect(current).to.equal(0)
+
+		a(1)
+		b(2)
+		expect(reruns).to.equal(2)
+		expect(current).to.equal(1)
+
+		condition(false)
+		expect(reruns).to.equal(3)
+		expect(current).to.equal(2)
+	end)
 end