feat: implement dark mode infrastructure, optimize images, and add SEO structured data

app/__tests__/api/book-reviews.test.tsx

@@ -0,0 +1,69 @@
+import { NextResponse } from 'next/server';
+import { GET } from '@/app/api/book-reviews/route';
+import { getBookReviews } from '@/lib/directus';
+
+jest.mock('@/lib/directus', () => ({
+  getBookReviews: jest.fn(),
+}));
+
+jest.mock('next/server', () => ({
+  NextRequest: jest.fn((url) => ({
+    url,
+  })),
+  NextResponse: {
+    json: jest.fn((data, options) => ({
+      json: async () => data,
+      status: options?.status || 200,
+    })),
+  },
+}));
+
+describe('GET /api/book-reviews', () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('should return book reviews from Directus', async () => {
+    const mockReviews = [
+      {
+        id: '1',
+        book_title: 'Test Book',
+        book_author: 'Test Author',
+        rating: 5,
+        review: 'Great book!',
+      },
+    ];
+
+    (getBookReviews as jest.Mock).mockResolvedValue(mockReviews);
+
+    const request = {
+      url: 'http://localhost/api/book-reviews?locale=en',
+    } as any;
+
+    await GET(request);
+
+    expect(NextResponse.json).toHaveBeenCalledWith(
+      expect.objectContaining({
+        bookReviews: mockReviews,
+        source: 'directus',
+      })
+    );
+  });
+
+  it('should return fallback when no reviews found', async () => {
+    (getBookReviews as jest.Mock).mockResolvedValue(null);
+
+    const request = {
+      url: 'http://localhost/api/book-reviews?locale=en',
+    } as any;
+
+    await GET(request);
+
+    expect(NextResponse.json).toHaveBeenCalledWith(
+      expect.objectContaining({
+        bookReviews: null,
+        source: 'fallback',
+      })
+    );
+  });
+});