graded test report

What this test actually proved

The cart makes four promises, written in Playwright on 7 September 2026.

bugs planted, bugs caught

1 of 4

Planted bugs checked: 4. We broke one behaviour at a time on purpose. Each run checked a copy with that behaviour broken. The test detected 1 and missed 3.

Which planted bugs the test detected

Planted bugs missed: 3. The test did not detect these broken behaviours.

Cart badge always shows 0
The test failed when this behaviour was broken.
No "added to cart" confirmation appears
The test did not detect this planted bug.
Subtotal ignores quantity (charges for one)
The test did not detect this planted bug.
Removing a cart item does nothing
The test did not detect this planted bug.

The test that was written

import { test, expect } from '@playwright/test';

test('the cart handles an item end to end', async ({ page }) => {
  await page.goto('/');

  await page.getByTestId('add-to-cart').first().click();

  // The one thing this test actually proves.
  await expect(page.getByTestId('cart-count')).toHaveText('1');

  await page.getByTestId('cart-link').click();
  await expect(page.getByTestId('cart-item')).toHaveCount(1);
});