test: add all sync tests

packages/charm-sync/src/__tests__/e2e.spec.luau

@@ -0,0 +1,96 @@
+local Charm = require("../../Charm")
+local client = require("../client")
+local config = require("../config")
+local server = require("../server")
+local suite = require("../../../../test/suite")
+
+local afterEach = suite.afterEach
+local test = suite.test
+
+afterEach(function()
+	server.reset()
+	client.clearAtoms()
+	config.preserveHistory = false
+end)
+
+test("should replicate server state to client", function()
+	local target = {}
+	local serverA = Charm.atom({ count = 0 })
+	local serverB = Charm.atom({ count = 0 })
+	local clientA = Charm.atom({ count = -1 })
+	local clientB = Charm.atom({ count = -1 })
+
+	client.registerAtoms({ a = clientA, b = clientB })
+	server.syncAtomsToClient(target, { a = serverA, b = serverB })
+	server.startSync(function(syncTarget, payloads)
+		if syncTarget == target then
+			client.applyPayloads(payloads)
+		end
+	end)
+
+	server.flush()
+	assert(clientA().count == 0, "Client atom A should be initialized to 0")
+	assert(clientB().count == 0, "Client atom B should be initialized to 0")
+
+	serverA({ count = 1 })
+	serverB({ count = 1 })
+	server.flush()
+	assert(clientA().count == 1, "Client atom A should be updated to 1")
+	assert(clientB().count == 1, "Client atom B should be updated to 1")
+
+	local prevClientB = clientB()
+	serverA({ count = 2 })
+	server.flush()
+	assert(clientA().count == 2, "Client atom A should be updated to 2")
+	assert(clientB() == prevClientB, "Client atom B should not be updated")
+end)
+
+test("should replicate historical server state to client", function()
+	local target = {}
+	local serverA = Charm.atom({ count = 0 })
+	local serverB = Charm.atom({ count = 0 })
+	local clientA = Charm.atom({ count = -1 })
+	local clientB = Charm.atom({ count = -1 })
+
+	config.preserveHistory = true
+
+	client.registerAtoms({ a = clientA, b = clientB })
+	server.syncAtomsToClient(target, { a = serverA, b = serverB })
+	server.startSync(function(syncTarget, payloads)
+		if syncTarget == target then
+			client.applyPayloads(payloads)
+		end
+	end)
+
+	local expectedA = { -1, 0, 1, 2, 3, 4 }
+	local expectedB = { -1, 0, 1, 2 }
+
+	Charm.effect(function()
+		local expected = table.remove(expectedA, 1)
+		assert(expected == clientA().count, `Client atom A should be {expected}`)
+	end)
+
+	Charm.effect(function()
+		local expected = table.remove(expectedB, 1)
+		assert(expected == clientB().count, `Client atom B should be {expected}`)
+	end)
+
+	server.flush()
+
+	serverA({ count = 1 })
+	serverA({ count = 2 })
+	serverB({ count = 1 })
+	serverB({ count = 2 })
+	server.flush()
+	assert(clientA().count == 2, "Client atom A should be updated to 2")
+	assert(clientB().count == 2, "Client atom B should be updated to 2")
+
+	local prevClientB = clientB()
+	serverA({ count = 3 })
+	serverA({ count = 4 })
+	server.flush()
+	assert(clientA().count == 4, "Client atom A should be updated to 4")
+	assert(clientB() == prevClientB, "Client atom B should not be updated")
+end)
+
+return {}