refactor: embrace scope cleanup, restructure code

pkgs/charm-sync/__tests__/server.spec.luau

@@ -0,0 +1,102 @@
+local ReplicatedStorage = game:GetService("ReplicatedStorage")
+local ServerScriptService = game:GetService("ServerScriptService")
+
+local Charm = require(ReplicatedStorage.Packages.Charm)
+local CharmSync = require(ReplicatedStorage.Packages.CharmSync)
+local suite = require(ServerScriptService.Tests.suite)
+
+type SyncPayload = CharmSync.SyncPayload
+
+local atom = Charm.atom
+local server = CharmSync.server
+local patch = CharmSync.patch
+local test = suite.test
+
+local target: Player = {} :: any
+
+test("sends state to new players", function()
+	local a = atom(1)
+	local server = server({ atoms = { a = a }, interval = -1 })
+	local player: Player, payload: SyncPayload
+
+	local disconnect = server:connect(function(...)
+		player, payload = ...
+	end)
+
+	server:hydrate(target)
+
+	assert(player == target)
+	assert(payload.type == "init")
+	assert(payload.data.a == 1)
+
+	disconnect()
+end)
+
+test("sends state patches", function()
+	local a = atom({ b = 1, c = 2 } :: { [string]: number? })
+	local server = server({ atoms = { a = a }, interval = -1 })
+	local player: Player, payload: SyncPayload
+
+	local disconnect = server:connect(function(...)
+		player, payload = ...
+	end)
+
+	a({ b = 1, c = 5 })
+	server:_sendPatch(target)
+
+	assert(player == target)
+	assert(payload.type == "patch")
+	assert(payload.data.a.b == nil)
+	assert(payload.data.a.c == 5)
+
+	a({ b = 1, d = 1 })
+	server:_sendPatch(target)
+
+	assert(payload.data.a.b == nil)
+	assert(patch.isNone(payload.data.a.c) == true)
+	assert(payload.data.a.d == 1)
+
+	disconnect()
+end)
+
+test("preserves history", function()
+	local a = atom(1)
+	local b = atom(1)
+	local payloads: { SyncPayload }
+
+	local server = server({
+		atoms = { a = a, b = b },
+		interval = -1,
+		preserveHistory = true,
+	})
+
+	local disconnect = server:connect(function(_, ...)
+		payloads = { ... }
+	end)
+
+	a(2)
+	b(2)
+	server:_sendPatch(target)
+
+	assert(#payloads == 1)
+	assert(payloads[1].type == "patch")
+	assert(payloads[1].data.a == 2)
+	assert(payloads[1].data.b == 2)
+
+	a(3)
+	a(4)
+	b(3)
+	server:_sendPatch(target)
+
+	assert(#payloads == 2)
+	assert(payloads[1].type == "patch")
+	assert(payloads[1].data.a == 3)
+	assert(payloads[1].data.b == nil)
+	assert(payloads[2].type == "patch")
+	assert(payloads[2].data.a == 4)
+	assert(payloads[2].data.b == 3)
+
+	disconnect()
+end)
+
+return {}