feat: Move language option to profile setting (#387)

backend/config/locale.js

@@ -0,0 +1 @@
+export const SUPPORTED_LOCALES = ['de', 'en', 'pt-BR', 'zh-CN', 'ja'];

backend/migrations/20260204151833-add-column-locale-user-table.js

@@ -0,0 +1,10 @@
+export async function up(queryInterface, Sequelize) {
+  await queryInterface.addColumn('users', 'locale', {
+    type: Sequelize.STRING(20),
+    allowNull: true,
+  });
+}
+
+export async function down(queryInterface) {
+  await queryInterface.removeColumn('users', 'locale');
+}

backend/models/users.js

@@ -22,6 +22,10 @@ function defineUser(sequelize, DataTypes) {
       avatarPath: {
         type: DataTypes.STRING,
       },
+      locale: {
+        type: DataTypes.STRING(20),
+        allowNull: true,
+      },
     },
     { underscored: true }
   );

backend/routes/users/updateAvatar.js

@@ -126,7 +126,7 @@ export default function (sequelize) {
 
       // Return updated user without password
       const updatedUser = await User.findByPk(userId, {
-        attributes: ['id', 'email', 'username', 'role', 'avatarPath'],
+        attributes: ['id', 'email', 'username', 'role', 'avatarPath', 'locale'],
       });
 
       res.json({ user: updatedUser });

backend/routes/users/updateLocale.js

@@ -0,0 +1,46 @@
+import express from 'express';
+import { DataTypes } from 'sequelize';
+import defineUser from '../../models/users.js';
+import authMiddleware from '../../middleware/auth.js';
+import { SUPPORTED_LOCALES } from '../../config/locale.js';
+const router = express.Router();
+
+export default function (sequelize) {
+  const { verifySignedIn } = authMiddleware(sequelize);
+  const User = defineUser(sequelize, DataTypes);
+
+  router.put('/locale', verifySignedIn, async (req, res) => {
+    try {
+      const userId = req.userId;
+
+      const user = await User.findByPk(userId);
+      if (!user) {
+        return res.status(404).send('User not found');
+      }
+
+      const { locale } = req.body;
+
+      const normalizedLocale = typeof locale === 'string' ? locale.trim() : '';
+      if (!normalizedLocale || normalizedLocale.length === 0) {
+        return res.status(400).send('Locale is required');
+      }
+
+      if (!SUPPORTED_LOCALES.includes(normalizedLocale)) {
+        return res.status(400).send('Invalid locale');
+      }
+
+      await user.update({ locale: normalizedLocale });
+
+      const updatedUser = await User.findByPk(userId, {
+        attributes: ['id', 'email', 'username', 'role', 'avatarPath', 'locale'],
+      });
+
+      res.json({ user: updatedUser });
+    } catch (error) {
+      console.error(error);
+      res.status(500).send('Internal Server Error');
+    }
+  });
+
+  return router;
+}

backend/routes/users/updateLocale.test.js

@@ -0,0 +1,92 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import request from 'supertest';
+import express from 'express';
+import { Sequelize } from 'sequelize';
+import { SUPPORTED_LOCALES } from '../../config/locale.js';
+import updateLocaleRoute from './updateLocale.js';
+
+// mock of authentication middleware
+let mockUserId = 1;
+vi.mock('../../middleware/auth.js', () => ({
+  default: () => ({
+    verifySignedIn: vi.fn((req, res, next) => {
+      req.userId = mockUserId; // Mock user ID
+      next();
+    }),
+  }),
+}));
+
+// mock defineUser
+const mockUsers = new Map();
+const mockUser = {
+  findByPk: vi.fn((id) => {
+    const user = mockUsers.get(id);
+    if (!user) return null;
+    return {
+      ...user,
+      update: vi.fn(async (data) => {
+        Object.assign(user, data);
+        return user;
+      }),
+    };
+  }),
+};
+
+vi.mock('../../models/users.js', () => ({
+  default: () => mockUser,
+}));
+
+describe('User Locale Routes', () => {
+  let app;
+  const sequelize = new Sequelize({
+    dialect: 'sqlite',
+    logging: false,
+  });
+
+  beforeEach(() => {
+    app = express();
+    app.use(express.json());
+    app.use('/users', updateLocaleRoute(sequelize));
+
+    // Reset mock users
+    mockUsers.clear();
+    mockUserId = 1;
+
+    // Create a test user
+    mockUsers.set(1, {
+      id: 1,
+      email: 'test@example.com',
+      username: 'testuser',
+      password: '',
+      role: 1,
+      avatarPath: null,
+      locale: null,
+    });
+
+    vi.clearAllMocks();
+  });
+
+  it('should update locale', async () => {
+    const newLocale = SUPPORTED_LOCALES[0];
+    const response = await request(app).put('/users/locale').send({ locale: newLocale });
+
+    expect(response.status).toBe(200);
+    expect(response.body.user.locale).toBe(newLocale);
+  });
+
+  it('should replace existing locale', async () => {
+    mockUsers.set(1, {
+      locale: SUPPORTED_LOCALES[0],
+    });
+    const response = await request(app).put('/users/locale').send({ locale: SUPPORTED_LOCALES[1] });
+
+    expect(response.status).toBe(200);
+    expect(response.body.user.locale).toBe(SUPPORTED_LOCALES[1]);
+  });
+
+  it.each([' ', 'chinese', 'english'])('should reject not supported locale: %s', async (locale) => {
+    const response = await request(app).put('/users/locale').send({ locale });
+
+    expect(response.status).toBe(400);
+  });
+});

backend/routes/users/updateUsername.js

@@ -26,7 +26,7 @@ export default function (sequelize) {
 
       // Return updated user without password
       const updatedUser = await User.findByPk(userId, {
-        attributes: ['id', 'email', 'username', 'role', 'avatarPath'],
+        attributes: ['id', 'email', 'username', 'role', 'avatarPath', 'locale'],
       });
 
       res.json({ user: updatedUser });

backend/server.js

@@ -53,6 +53,7 @@ import usersSearchRoute from './routes/users/search.js';
 import usersUpdateUsernameRoute from './routes/users/updateUsername.js';
 import usersUpdatePasswordRoute from './routes/users/updatePassword.js';
 import usersAdminResetPasswordRoute from './routes/users/adminResetPassword.js';
+import usersUpdateLocaleRoute from './routes/users/updateLocale.js';
 import usersUpdateAvatarRoute from './routes/users/updateAvatar.js';
 import usersUpdateRoleRoute from './routes/users/updateRole.js';
 import signUpRoute from './routes/users/signup.js';
@@ -63,6 +64,7 @@ app.use('/users', usersSearchRoute(sequelize));
 app.use('/users', usersUpdateUsernameRoute(sequelize));
 app.use('/users', usersUpdatePasswordRoute(sequelize));
 app.use('/users', usersAdminResetPasswordRoute(sequelize));
+app.use('/users', usersUpdateLocaleRoute(sequelize));
 app.use('/users', usersUpdateAvatarRoute(sequelize));
 app.use('/users', usersUpdateRoleRoute(sequelize));
 app.use('/users', signUpRoute(sequelize));