feat(ai): Gemini-Client mit Timeout, 1x-Retry und Fehler-Codes

tests/unit/gemini-client.test.ts

@@ -0,0 +1,128 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+
+const mockGenerateContent = vi.fn();
+
+vi.mock('@google/generative-ai', async () => {
+  const actual = await vi.importActual<typeof import('@google/generative-ai')>(
+    '@google/generative-ai'
+  );
+  return {
+    ...actual,
+    GoogleGenerativeAI: vi.fn().mockImplementation(() => ({
+      getGenerativeModel: () => ({ generateContent: mockGenerateContent })
+    }))
+  };
+});
+
+// $env/dynamic/private is mocked via SvelteKit's own mock; here we lean on
+// process.env (the client falls back to it).
+import {
+  extractRecipeFromImage,
+  GeminiError
+} from '../../src/lib/server/ai/gemini-client';
+
+beforeEach(() => {
+  mockGenerateContent.mockReset();
+  process.env.GEMINI_API_KEY = 'test-key';
+  process.env.GEMINI_MODEL = 'gemini-2.5-flash';
+  process.env.GEMINI_TIMEOUT_MS = '5000';
+});
+
+const validResponse = {
+  title: 'Apfelkuchen',
+  servings_default: 8,
+  servings_unit: 'Stück',
+  prep_time_min: 20,
+  cook_time_min: 45,
+  total_time_min: null,
+  ingredients: [{ quantity: 500, unit: 'g', name: 'Mehl', note: null }],
+  steps: [{ text: 'Ofen auf 180 °C vorheizen.' }]
+};
+
+describe('extractRecipeFromImage', () => {
+  it('happy path: returns parsed recipe data', async () => {
+    mockGenerateContent.mockResolvedValueOnce({
+      response: { text: () => JSON.stringify(validResponse) }
+    });
+    const result = await extractRecipeFromImage(Buffer.from('fake'), 'image/jpeg');
+    expect(result.title).toBe('Apfelkuchen');
+    expect(result.ingredients).toHaveLength(1);
+  });
+
+  it('retries once on schema-invalid JSON, then succeeds', async () => {
+    mockGenerateContent
+      .mockResolvedValueOnce({ response: { text: () => '{"title": "no arrays"}' } })
+      .mockResolvedValueOnce({
+        response: { text: () => JSON.stringify(validResponse) }
+      });
+    const result = await extractRecipeFromImage(Buffer.from('fake'), 'image/jpeg');
+    expect(result.title).toBe('Apfelkuchen');
+    expect(mockGenerateContent).toHaveBeenCalledTimes(2);
+  });
+
+  it('throws AI_FAILED after schema-invalid + retry also invalid', async () => {
+    mockGenerateContent
+      .mockResolvedValueOnce({ response: { text: () => '{}' } })
+      .mockResolvedValueOnce({
+        response: { text: () => '{"title": "still bad"}' }
+      });
+    await expect(
+      extractRecipeFromImage(Buffer.from('fake'), 'image/jpeg')
+    ).rejects.toMatchObject({ code: 'AI_FAILED' });
+  });
+
+  it('throws AI_RATE_LIMITED without retry on 429', async () => {
+    const err = new Error('429 Too Many Requests') as Error & { status?: number };
+    err.status = 429;
+    mockGenerateContent.mockRejectedValueOnce(err);
+    await expect(
+      extractRecipeFromImage(Buffer.from('fake'), 'image/jpeg')
+    ).rejects.toMatchObject({ code: 'AI_RATE_LIMITED' });
+    expect(mockGenerateContent).toHaveBeenCalledTimes(1);
+  });
+
+  it('retries once on 5xx, then succeeds', async () => {
+    const err = new Error('500 Server Error') as Error & { status?: number };
+    err.status = 500;
+    mockGenerateContent
+      .mockRejectedValueOnce(err)
+      .mockResolvedValueOnce({
+        response: { text: () => JSON.stringify(validResponse) }
+      });
+    const result = await extractRecipeFromImage(Buffer.from('fake'), 'image/jpeg');
+    expect(result.title).toBe('Apfelkuchen');
+    expect(mockGenerateContent).toHaveBeenCalledTimes(2);
+  });
+
+  it('throws AI_FAILED after 5xx + retry also fails', async () => {
+    const err = new Error('500') as Error & { status?: number };
+    err.status = 500;
+    mockGenerateContent.mockRejectedValue(err);
+    await expect(
+      extractRecipeFromImage(Buffer.from('fake'), 'image/jpeg')
+    ).rejects.toMatchObject({ code: 'AI_FAILED' });
+    expect(mockGenerateContent).toHaveBeenCalledTimes(2);
+  });
+
+  it('throws AI_TIMEOUT when generateContent never resolves', async () => {
+    process.env.GEMINI_TIMEOUT_MS = '50';
+    mockGenerateContent.mockImplementation(
+      () => new Promise(() => {}) // never resolves
+    );
+    await expect(
+      extractRecipeFromImage(Buffer.from('fake'), 'image/jpeg')
+    ).rejects.toMatchObject({ code: 'AI_TIMEOUT' });
+  });
+
+  it('throws AI_NOT_CONFIGURED when GEMINI_API_KEY is empty', async () => {
+    process.env.GEMINI_API_KEY = '';
+    await expect(
+      extractRecipeFromImage(Buffer.from('fake'), 'image/jpeg')
+    ).rejects.toMatchObject({ code: 'AI_NOT_CONFIGURED' });
+  });
+
+  it('GeminiError has a code property', () => {
+    const e = new GeminiError('AI_FAILED', 'x');
+    expect(e.code).toBe('AI_FAILED');
+  });
+});