fix(livechat): registering guest multiple times cause message loss

.changeset/nine-houses-reply.md

@@ -0,0 +1,6 @@
+---
+"@rocket.chat/meteor": patch
+"@rocket.chat/livechat": patch
+---
+
+Livechat: A registered user loses their messages if 'registerGuest' is called using the same token.

apps/meteor/tests/e2e/omnichannel/omnichannel-livechat-api.spec.ts

@@ -460,8 +460,6 @@ test.describe('OC - Livechat API', () => {
 			};
 
 			await test.step('Expect registerGuest work with the same token, multiple times', async () => {
-				test.fail();
-
 				await poLiveChat.page.evaluate(() => window.RocketChat.livechat.maximizeWidget());
 				await expect(page.frameLocator('#rocketchat-iframe').getByText('Start Chat')).toBeVisible();
 

packages/livechat/src/lib/hooks.js

@@ -9,12 +9,49 @@ import { createToken } from './random';
 import { loadMessages } from './room';
 import Triggers from './triggers';
 
+const evaluateChangesAndLoadConfigByFields = async (fn) => {
+	const oldStore = JSON.parse(
+		JSON.stringify({
+			user: store.state.user || {},
+			department: store.state.department,
+			token: store.state.token,
+		}),
+	);
+	await fn();
+
+	/**
+	 * it solves the issues where the registerGuest is called every time the widget is opened
+	 * and the guest is already registered. If there is nothing different in the data,
+	 * it will not call the loadConfig again.
+	 *
+	 * if user changes, it will call loadConfig
+	 * if department changes, it will call loadConfig
+	 * if token changes, it will call loadConfig
+	 */
+
+	if (oldStore.user._id !== store.state.user?._id) {
+		await loadConfig();
+		await loadMessages();
+		return;
+	}
+
+	if (oldStore.department !== store.state.department) {
+		await loadConfig();
+		await loadMessages();
+		return;
+	}
+
+	if (oldStore.token !== store.state.token) {
+		await loadConfig();
+		await loadMessages();
+	}
+};
+
 const createOrUpdateGuest = async (guest) => {
 	const { token } = guest;
 	token && (await store.setState({ token }));
 	const { visitor: user } = await Livechat.grantVisitor({ visitor: { ...guest } });
 	store.setState({ user });
-	await loadConfig();
 };
 
 const updateIframeGuestData = (data) => {
@@ -76,15 +113,16 @@ const api = {
 		});
 	},
 
-	async setDepartment(value) {
+	setDepartment: async (value) => {
+		await evaluateChangesAndLoadConfigByFields(async () => api._setDepartment(value));
+	},
+
+	async _setDepartment(value) {
 		const {
-			user,
 			config: { departments = [] },
 			defaultAgent,
 		} = store.state;
 
-		const { department: existingDepartment } = user || {};
-
 		const department = departments.find((dep) => dep._id === value || dep.name === value)?._id || '';
 
 		updateIframeGuestData({ department });
@@ -93,11 +131,6 @@ const api = {
 		if (defaultAgent && defaultAgent.department !== department) {
 			store.setState({ defaultAgent: null });
 		}
-
-		if (department !== existingDepartment) {
-			await loadConfig();
-			await loadMessages();
-		}
 	},
 
 	async setBusinessUnit(newBusinessUnit) {
@@ -143,7 +176,9 @@ const api = {
 		if (token === localToken) {
 			return;
 		}
-		await createOrUpdateGuest({ token });
+		await evaluateChangesAndLoadConfigByFields(async () => {
+			await createOrUpdateGuest({ token });
+		});
 	},
 
 	setGuestName(name) {
@@ -159,17 +194,19 @@ const api = {
 			return;
 		}
 
-		if (!data.token) {
-			data.token = createToken();
-		}
+		await evaluateChangesAndLoadConfigByFields(async () => {
+			if (!data.token) {
+				data.token = createToken();
+			}
 
-		if (data.department) {
-			api.setDepartment(data.department);
-		}
+			if (data.department) {
+				await api._setDepartment(data.department);
+			}
 
-		Livechat.unsubscribeAll();
+			Livechat.unsubscribeAll();
 
-		await createOrUpdateGuest(data);
+			await createOrUpdateGuest(data);
+		});
 	},
 
 	async setLanguage(language) {