fix: avoid reconnecting to dependencies after cleanup (#14)

* fix: cancel reconnection when unsubscribing

* test: remove print

* feat: allow factory to return nil

* perf: use `next` iteration

src/sync/client.luau

@@ -36,7 +36,7 @@ local function client(options: ClientOptions): ClientSyncer
 		for index = 1, select("#", ...) do
 			local payload = select(index, ...)
 
-			for key, state in payload.data do
+			for key, state in next, payload.data do
 				if payload.type == "patch" then
 					atoms[key](patch.apply(atoms[key](), state))
 				else

src/sync/patch.luau

@@ -13,7 +13,7 @@ end
 local function diff(prevState: { [any]: any }, nextState: { [any]: any })
 	local patches = table.clone(nextState)
 
-	for key, previous in prevState do
+	for key, previous in next, prevState do
 		local next = nextState[key]
 
 		if previous == next then
@@ -26,7 +26,7 @@ local function diff(prevState: { [any]: any }, nextState: { [any]: any })
 	end
 
 	if _G.__DEV__ then
-		for key, value in prevState do
+		for key, value in next, prevState do
 			validate(value, key)
 		end
 
@@ -50,7 +50,7 @@ local function apply(state: any, patches: any): any
 	local nextState = table.clone(state)
 	local stateIsArray = state[1] ~= nil
 
-	for key, patch in patches do
+	for key, patch in next, patches do
 		-- Diff-checking an array produces a sparse array, which will not be
 		-- preserved when converted to JSON. To prevent this, we turn string
 		-- keys back into numeric keys.

src/sync/server.luau

@@ -72,7 +72,7 @@ local function server(options: ServerOptions): ServerSyncer
 
 		local function getSnapshot()
 			local snapshot: { [string]: any } = {}
-			for key, atom in options.atoms do
+			for key, atom in next, options.atoms do
 				snapshot[key] = atom()
 			end
 			return snapshot
@@ -105,7 +105,7 @@ local function server(options: ServerOptions): ServerSyncer
 
 		-- Populate the initial state and snapshot for each atom.
 		-- Subscribe to each atom and update the state when it changes.
-		for key, atom in options.atoms do
+		for key, atom in next, options.atoms do
 			cleanups[key] = subscribe(atom, function(current, previous)
 				pushSnapshot(key, current, previous)
 				changed = true
@@ -122,7 +122,7 @@ local function server(options: ServerOptions): ServerSyncer
 			local payloads: { SyncPayload } = {}
 			local lastSnapshot
 
-			for index, snapshot in snapshots do
+			for index, snapshot in next, snapshots do
 				lastSnapshot = snapshot
 
 				if index == 1 then
@@ -138,14 +138,14 @@ local function server(options: ServerOptions): ServerSyncer
 			snapshots = { lastSnapshot }
 			changed = false
 
-			for _, player in Players:GetPlayers() do
+			for _, player in next, Players:GetPlayers() do
 				callback(player, unpack(payloads))
 			end
 		end, options.interval or 0)
 
 		return function()
 			disconnect()
-			for _, cleanup in cleanups do
+			for _, cleanup in next, cleanups do
 				cleanup()
 			end
 		end
@@ -170,7 +170,7 @@ local function server(options: ServerOptions): ServerSyncer
 
 		local payloads: { SyncPayload } = {}
 
-		for index, snapshot in snapshots do
+		for index, snapshot in next, snapshots do
 			if index == 1 then
 				continue
 			end

src/sync/validate.luau

@@ -8,7 +8,7 @@ local function isUnsafeTable(object: { [any]: any })
 	local objectSize = 0
 
 	-- All keys must have the same type
-	for key in object do
+	for key in next, object do
 		local currentType = type(key)
 
 		if not keyType and SAFE_KEYS[currentType] then