test(web): add middleware + i18n + messages test suites (GOO-60)

Cover frontend middleware auth/locale logic, i18n config/routing/request/navigation,
and vi/en message parity — 91 new tests across 6 files.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/i18n/__tests__/request.spec.ts

@@ -0,0 +1,121 @@
+import { describe, expect, it, vi, beforeEach } from 'vitest';
+
+// Mock the routing module
+vi.mock('../routing', () => ({
+  routing: {
+    locales: ['vi', 'en'] as const,
+    defaultLocale: 'vi',
+    localePrefix: 'as-needed',
+  },
+}));
+
+// Track getRequestConfig calls
+let capturedConfigFn: ((params: { requestLocale: Promise<string | undefined> }) => Promise<{
+  locale: string;
+  messages: Record<string, unknown>;
+}>) | null = null;
+
+vi.mock('next-intl/server', () => ({
+  getRequestConfig: (fn: typeof capturedConfigFn) => {
+    capturedConfigFn = fn;
+    return fn;
+  },
+}));
+
+// Provide message mocks
+vi.mock('../../messages/vi.json', () => ({
+  default: {
+    common: { goodgo: 'GoodGo', loading: 'Đang tải...' },
+    metadata: { title: 'GoodGo — Nền tảng Bất động sản Việt Nam' },
+  },
+}));
+
+vi.mock('../../messages/en.json', () => ({
+  default: {
+    common: { goodgo: 'GoodGo', loading: 'Loading...' },
+    metadata: { title: 'GoodGo — Vietnam Real Estate Platform' },
+  },
+}));
+
+// Import triggers getRequestConfig, which captures the config function
+await import('../request');
+
+describe('i18n/request', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('captures a config function via getRequestConfig', () => {
+    expect(capturedConfigFn).toBeTypeOf('function');
+  });
+
+  describe('locale resolution', () => {
+    it('uses the requested locale when it is valid (vi)', async () => {
+      const result = await capturedConfigFn!({
+        requestLocale: Promise.resolve('vi'),
+      });
+      expect(result.locale).toBe('vi');
+    });
+
+    it('uses the requested locale when it is valid (en)', async () => {
+      const result = await capturedConfigFn!({
+        requestLocale: Promise.resolve('en'),
+      });
+      expect(result.locale).toBe('en');
+    });
+
+    it('falls back to default locale (vi) when requestLocale is undefined', async () => {
+      const result = await capturedConfigFn!({
+        requestLocale: Promise.resolve(undefined),
+      });
+      expect(result.locale).toBe('vi');
+    });
+
+    it('falls back to default locale (vi) when requestLocale is empty string', async () => {
+      const result = await capturedConfigFn!({
+        requestLocale: Promise.resolve(''),
+      });
+      expect(result.locale).toBe('vi');
+    });
+
+    it('falls back to default locale (vi) for an invalid locale', async () => {
+      const result = await capturedConfigFn!({
+        requestLocale: Promise.resolve('fr'),
+      });
+      expect(result.locale).toBe('vi');
+    });
+
+    it('falls back to default locale (vi) for another invalid locale', async () => {
+      const result = await capturedConfigFn!({
+        requestLocale: Promise.resolve('ja'),
+      });
+      expect(result.locale).toBe('vi');
+    });
+  });
+
+  describe('message loading', () => {
+    it('loads Vietnamese messages for vi locale', async () => {
+      const result = await capturedConfigFn!({
+        requestLocale: Promise.resolve('vi'),
+      });
+      expect(result.messages).toBeDefined();
+      expect((result.messages as Record<string, Record<string, string>>).common.loading).toBe('Đang tải...');
+    });
+
+    it('loads English messages for en locale', async () => {
+      const result = await capturedConfigFn!({
+        requestLocale: Promise.resolve('en'),
+      });
+      expect(result.messages).toBeDefined();
+      expect((result.messages as Record<string, Record<string, string>>).common.loading).toBe('Loading...');
+    });
+
+    it('loads Vietnamese messages when falling back from invalid locale', async () => {
+      const result = await capturedConfigFn!({
+        requestLocale: Promise.resolve('fr'),
+      });
+      expect(result.locale).toBe('vi');
+      expect((result.messages as Record<string, Record<string, string>>).common.loading).toBe('Đang tải...');
+    });
+  });
+});