QA, tests, maintenance et modernisation

// Playwright E2E - Checkout + API mocking
import { test, expect } from '@playwright/test';

test.describe('Checkout flow', () => {
  test.beforeEach(async ({ page }) => {
    await page.goto('/cart');
    await page.route('**/api/inventory', (route) =>
      route.fulfill({ json: { stock: 10 } })
    );
  });

  test('should complete purchase', async ({ page }) => {
    await page.click('[data-testid="checkout"]');
    await page.fill('[name="card"]', '4111111111111111');
    await page.click('[data-testid="submit-payment"]');
    await expect(page).toHaveURL('/success');
  });

  test('should validate stock before checkout', async ({ page }) => {
    await page.evaluate(() =>
      localStorage.setItem('cart', '[{"id":1,"qty":99}]')
    );
    await page.reload();
    await expect(page.locator('[data-testid="stock-error"]'))
      .toContainText('insufficient');
  });
});