klz-cables.com/tests/og-image.test.ts

import { describe, it, expect } from 'vitest';

const BASE_URL = process.env.TEST_URL || 'http://localhost:3000';

describe('OG Image Generation', () => {
  const locales = ['de', 'en'];
  const productSlugs = ['nay2y']; // Based on data/products/de/nay2y.mdx

  async function verifyImageResponse(response: Response) {
    expect(response.status).toBe(200);
    expect(response.headers.get('content-type')).toContain('image/png');
    
    const buffer = await response.arrayBuffer();
    const bytes = new Uint8Array(buffer);
    
    // Check for PNG signature: 89 50 4E 47 0D 0A 1A 0A
    expect(bytes[0]).toBe(0x89);
    expect(bytes[1]).toBe(0x50);
    expect(bytes[2]).toBe(0x4E);
    expect(bytes[3]).toBe(0x47);
    
    // Check that the image is not empty and has a reasonable size
    // A 1200x630 OG image should be at least 4KB
    expect(bytes.length).toBeGreaterThan(4000);
  }

  locales.forEach((locale) => {
    it(`should generate main OG image for ${locale}`, async () => {
      const url = `${BASE_URL}/${locale}/opengraph-image`;
      const response = await fetch(url);
      await verifyImageResponse(response);
    }, 30000);

    it(`should generate product OG image for ${locale} with slug ${productSlugs[0]}`, async () => {
      const url = `${BASE_URL}/${locale}/api/og/product?slug=${productSlugs[0]}`;
      const response = await fetch(url);
      await verifyImageResponse(response);
    }, 30000);

    it(`should return 400 for product OG image without slug in ${locale}`, async () => {
      const url = `${BASE_URL}/${locale}/api/og/product`;
      const response = await fetch(url);
      expect(response.status).toBe(400);
    }, 30000);
  });

  it('should generate blog OG image', async () => {
    const url = `${BASE_URL}/de/blog/opengraph-image`;
    const response = await fetch(url);
    await verifyImageResponse(response);
  }, 30000);
});