From 382bc3a90466da8e4dfa1d8e742d61668563a779 Mon Sep 17 00:00:00 2001
From: Richard <richerd.rdc@gmail.com>
Date: Wed, 27 Mar 2024 23:49:33 -0700
Subject: [PATCH] refactor: refine types and code

---
 src/__tests__/sync/client.spec.luau |  2 +-
 src/__tests__/sync/server.spec.luau |  2 +-
 src/index.d.ts                      | 36 +++++++++++++++--------------
 src/init.luau                       |  8 +++----
 src/sync/server.luau                |  6 +++--
 src/types.luau                      |  2 +-
 6 files changed, 30 insertions(+), 26 deletions(-)

diff --git a/src/__tests__/sync/client.spec.luau b/src/__tests__/sync/client.spec.luau
index ea961f8..5aac613 100644
--- a/src/__tests__/sync/client.spec.luau
+++ b/src/__tests__/sync/client.spec.luau
@@ -7,7 +7,7 @@ return function()
 		local client = sync.client({ atoms = { a = a } })
 
 		client:sync({
-			type = "set",
+			type = "init",
 			data = { a = 2 },
 		})
 
diff --git a/src/__tests__/sync/server.spec.luau b/src/__tests__/sync/server.spec.luau
index 972d78b..206773c 100644
--- a/src/__tests__/sync/server.spec.luau
+++ b/src/__tests__/sync/server.spec.luau
@@ -17,7 +17,7 @@ return function()
 		server:hydrate(target)
 
 		expect(player).to.equal(target)
-		expect(payload.type).to.equal("set")
+		expect(payload.type).to.equal("init")
 		expect(payload.data.a).to.equal(1)
 
 		disconnect()
diff --git a/src/index.d.ts b/src/index.d.ts
index 89ebe1c..eb3e721 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -76,34 +76,36 @@ declare namespace Charm {
 	// Sync
 
 	const sync: {
-		client(options: ClientOptions): ClientSyncer;
-		server(options: ServerOptions): ServerSyncer;
+		client: <T extends Record<string, Atom<any>>>(options: ClientOptions<T>) => ClientSyncer<T>;
+		server: <T extends Record<string, Atom<any>>>(options: ServerOptions<T>) => ServerSyncer<T>;
+		collect: (root: Instance) => Record<string, Atom<any>>;
 	};
 
-	interface SyncPatch {
-		[key: string | number | symbol]: SyncPatch | { __none: "__none" } | string | number | boolean | undefined;
+	interface None {
+		__none: "__none";
 	}
 
-	interface SyncPayload {
-		type: "set" | "patch";
-		data: SyncPatch;
+	type SyncPatch<T> = {
+		readonly [P in keyof T]?: (T[P] extends object ? SyncPatch<T[P]> : T[P]) | (T[P] extends undefined ? None : never);
+	};
+
+	type SyncPayload<T> = { type: "init"; data: T } | { type: "patch"; data: SyncPatch<T> };
+
+	interface ClientOptions<T extends Record<string, Atom<any>>> {
+		atoms: T;
 	}
 
-	interface ClientOptions {
-		atoms: Record<string, Atom<any>>;
-	}
-
-	interface ServerOptions {
-		atoms: Record<string, Atom<any>>;
+	interface ServerOptions<T extends Record<string, Atom<any>>> {
+		atoms: T;
 		interval?: number;
 	}
 
-	interface ClientSyncer {
-		sync(payload: SyncPayload): void;
+	interface ClientSyncer<T extends Record<string, Atom<any>>> {
+		sync(payload: SyncPayload<T>): void;
 	}
 
-	interface ServerSyncer {
-		connect(callback: (player: Player, payload: SyncPayload) => void): Cleanup;
+	interface ServerSyncer<T extends Record<string, Atom<any>>> {
+		connect(callback: (player: Player, payload: SyncPayload<T>) => void): Cleanup;
 		hydrate(player: Player): void;
 	}
 }
diff --git a/src/init.luau b/src/init.luau
index 9747c78..00ba0b3 100644
--- a/src/init.luau
+++ b/src/init.luau
@@ -21,16 +21,16 @@ export type SyncPayload = types.SyncPayload
 
 return {
 	atom = atom,
+	capture = capture,
 	derive = derive,
 	effect = effect,
 	isAtom = isAtom,
 	map = map,
 	observe = observe,
-	subscribe = subscribe,
-	unwrap = unwrap,
-	capture = capture,
-	sync = sync,
 	useAtom = useAtom,
 	useAtomState = useAtomState,
 	useSetAtom = useSetAtom,
+	subscribe = subscribe,
+	sync = sync,
+	unwrap = unwrap,
 }
diff --git a/src/sync/server.luau b/src/sync/server.luau
index db6645e..51dabb4 100644
--- a/src/sync/server.luau
+++ b/src/sync/server.luau
@@ -42,10 +42,12 @@ local function server(options: ServerOptions): ServerSyncer
 			state = getState()
 
 			if state ~= previous then
+				local diffs = patch.diff(previous, state)
+
 				for _, player in Players:GetPlayers() do
 					callback(player, {
 						type = "patch",
-						data = patch.diff(previous, state),
+						data = diffs,
 					})
 				end
 			end
@@ -66,7 +68,7 @@ local function server(options: ServerOptions): ServerSyncer
 		assert(sync, "connect() must be called before hydrate()")
 
 		sync(player, {
-			type = "set",
+			type = "init",
 			data = getState(),
 		})
 	end
diff --git a/src/types.luau b/src/types.luau
index ee08b65..f475b0f 100644
--- a/src/types.luau
+++ b/src/types.luau
@@ -9,7 +9,7 @@ export type AtomOptions<T> = {
 }
 
 export type SyncPayload = {
-	type: "patch" | "set",
+	type: "patch" | "init",
 	data: { [any]: any },
 }