chore: housekeeping

packages/charm-sync/src/client.luau

@@ -0,0 +1,76 @@
+local Charm = require(script.Parent.Parent.Charm)
+local patch = require(script.Parent.patch)
+local types = require(script.Parent.types)
+
+type AtomMap = types.AtomMap
+type SyncPayload = types.SyncPayload
+
+type ClientOptions = {
+	--- The atoms to synchronize with the server.
+	atoms: AtomMap,
+	--- Whether to ignore patches sent before the client has been hydrated.
+	--- Default is `true`.
+	ignoreUnhydrated: boolean?,
+}
+
+type ClientSyncer = {
+	--- Applies a patch or initializes the state of the atoms with the given
+	--- payload from the server.
+	---
+	--- @param ...payloads The patches or hydration payloads to apply.
+	sync: (self: ClientSyncer, ...SyncPayload) -> (),
+}
+
+--- Creates a `ClientSyncer` object that receives patches from the server and
+--- applies them to the local state.
+---
+--- @param options The atoms to synchronize with the server.
+--- @return A `ClientSyncer` object.
+local function client(options: ClientOptions): ClientSyncer
+	local atoms = options.atoms
+	local ignoreUnhydrated = options.ignoreUnhydrated ~= false
+
+	local self = {} :: ClientSyncer
+	local hydrated = false
+
+	local function hydrate(state: { [string | number]: any })
+		hydrated = true
+
+		for key, value in next, state do
+			local atom = atoms[key]
+			atom(value)
+		end
+	end
+
+	local function apply(data: { [string | number]: any })
+		local target = {}
+
+		for key, atom in next, atoms do
+			target[key] = atom()
+		end
+
+		target = patch.apply(target, data)
+
+		for key, atom in next, atoms do
+			atom(target[key])
+		end
+	end
+
+	function self:sync(...)
+		for index = 1, select("#", ...) do
+			local payload: SyncPayload = select(index, ...)
+
+			Charm.batched(function()
+				if payload.type == "init" then
+					hydrate(payload.data)
+				elseif not ignoreUnhydrated or hydrated then
+					apply(payload.data)
+				end
+			end)
+		end
+	end
+
+	return self
+end
+
+return client