fix: refine reactive proxy logic

packages/charm-sync/src/__tests__/server.spec.luau

@@ -102,6 +102,22 @@ test("should replicate partial state patches (reactive)", function()
 	assert(payloads[1].data.a.x == nil, "Expected patch payload to not contain value 'a.x'")
 end)
 
+test("should handle nested proxies", function()
+	local client = {}
+	local src = Charm.reactive({ (Charm.reactive({})) })
+	local payloads: {}? = nil
+
+	server.addSignalsToClient(client, { src = src })
+	server.connect(function(_, newPayloads)
+		payloads = newPayloads
+	end)
+	server.flush()
+
+	payloads = nil
+	server.flush()
+	assert(payloads == nil, "Expected no payloads to be sent for unchanged nested proxy")
+end)
+
 test("should init new clients", function()
 	local clientA = {}
 	local clientB = {}

packages/charm-sync/src/client.luau

@@ -26,7 +26,7 @@ local function addSignals(signals: { [string]: Setter | {} })
 		if type(signal) == "function" then
 			trackedSignals[key] = signal
 		else
-			trackedReactives[key] = getmetatable(signal :: ReactiveProxy).set
+			trackedReactives[key] = ((signal :: any) :: ReactiveProxy).__set
 		end
 	end
 end

packages/charm-sync/src/server.luau

@@ -33,7 +33,7 @@ local globalUpdates: { StateUpdate } = {}
 local clients: { [any]: ClientKeys } = {}
 
 local connection: RBXScriptConnection?
-local syncCallback: (client: any, payloads: { SyncPayload }) -> ()?
+local syncCallback: ((client: any, payloads: { SyncPayload }) -> ())?
 
 local function trackSignal<T>(key: string, getter: () -> T, identifier: unknown)
 	if trackedStates[key] then
@@ -47,8 +47,7 @@ local function trackSignal<T>(key: string, getter: () -> T, identifier: unknown)
 	local trackedState: TrackedState<T>
 	local initialValue = getter()
 	local rawInitialValue = Charm.toRaw(initialValue)
-	local initialIsReactive = initialValue ~= rawInitialValue
-	local snapshot = if initialIsReactive then utils.deepCopy(rawInitialValue) else initialValue
+	local snapshot = if initialValue ~= rawInitialValue then utils.deepCopy(rawInitialValue) else initialValue
 
 	local dispose = Charm.effect(function()
 		local newValue = getter()
@@ -62,12 +61,12 @@ local function trackSignal<T>(key: string, getter: () -> T, identifier: unknown)
 		-- When preserving history, we need to keep track of previous values
 		-- so we can create granular patches for each change.
 		if config.preserveHistory then
-			local oldSnapshot = snapshot
+			local prevSnapshot = snapshot
 			snapshot = if isReactive then utils.deepCopy(rawValue) else newValue
 			table.insert(globalUpdates, {
 				key = key,
 				newValue = snapshot,
-				oldValue = oldSnapshot,
+				oldValue = prevSnapshot,
 			})
 		end
 
@@ -79,7 +78,7 @@ local function trackSignal<T>(key: string, getter: () -> T, identifier: unknown)
 		identifier = identifier,
 		currentValue = rawInitialValue,
 		lastSyncedValue = snapshot,
-		isReactive = initialIsReactive,
+		isReactive = initialValue ~= rawInitialValue,
 		dispose = dispose,
 	}
 

packages/charm-sync/src/utils.luau

@@ -49,12 +49,13 @@ local function signalToAtom<T>(getter: () -> T, setter: (value: ((T) -> T) | T)
 end
 
 --[[
-	Returns a deep copy of the given table.
+	Returns a deep copy of the given table. Skips tables with metatables to
+	prevent copying reactive proxies.
 ]]
 local function deepCopy<T>(object: T): T
 	local copy: any = table.clone(object :: any)
 	for key, value in copy do
-		if type(value) == "table" then
+		if type(value) == "table" and getmetatable(value) == nil then
 			copy[key] = deepCopy(value)
 		end
 	end