Keep snapshot tests small and reviewed

How to do it

Prefer plain assertions on the fields that matter. When a snapshot helps, keep it under 50 lines and inline, such as toMatchInlineSnapshot() in Vitest or Jest, or inline-snapshot in Python. Never run the update flag just to make a red build green. Screenshot comparisons, such as Playwright's toHaveScreenshot(), need fixed fonts, data and browser versions.

Example

test('formats the order summary', () => {
  expect(formatSummary(makeOrder({ total: 1999 }))).toMatchInlineSnapshot(`"1 item, 19.99 EUR"`);
});

# Python with inline-snapshot
from inline_snapshot import snapshot

def test_formats_the_order_summary():
    assert format_summary(make_order(total=1999)) == snapshot("1 item, 19.99 EUR")

How to check

In continuous integration, a missing or changed snapshot fails the run instead of being written, as with Jest's --ci flag. No stored text snapshot is longer than 50 lines.