Writing Tests

Add meaningful test coverage with TDD enforcement.

Best for: Improving coverage, TDD practice
Time estimate: 10-30 minutes
Skills used: meow:qa-manual (E2E), meow:review (coverage audit)
Agents involved: tester, developer (if implementation needed)

Overview

MeowKit enforces TDD — tests must exist and fail BEFORE implementation. This workflow covers both adding unit tests to existing code and generating E2E tests from user flows.

Unit tests (TDD)

Step 1: Write failing tests first

The tester writes tests that define expected behavior:

/meow:cook add input validation to user registration

The tester writes tests BEFORE the developer touches implementation:

// tests/user-registration.test.ts (tester creates this)
test('rejects email without @ symbol', () => {
  expect(validateEmail('invalid')).toBe(false);
});

test('rejects password shorter than 8 characters', () => {
  expect(validatePassword('short')).toBe(false);
});

These tests fail — the validation functions don't exist yet.

Step 2: Developer implements to pass

The developer writes the minimum code to make tests green.

Step 3: Refactor

Both tester and developer refine — tests still pass after each change.

E2E tests (Playwright)

Step 1: Generate from spec

/meow:qa-manual tasks/plans/260327-checkout.md --generate

The meow:qa-manual skill:

1. Navigates the app like a human tester
2. Records every interaction as Playwright TypeScript code
3. Detects test ID convention (data-testid or data-cy)
4. Generates feature folder structure:

tests/e2e/checkout-flow/
├── common/
│   ├── checkoutSelectors.ts      # All locators centralized
│   ├── checkoutAssertions.ts     # Reusable assertions
│   └── checkoutIntercepts.ts     # API mocks
└── checkout-flow.spec.ts         # One describe block

Step 2: Verify selectors exist

The skill greps the source to verify each getByTestId() actually exists:

grep -rn 'data-testid="checkout-btn"' src/ → Found ✓
grep -rn 'data-testid="place-order"' src/ → Found ✓

Missing selectors get a warning comment and fallback locator.

Step 3: Run the generated tests

npx playwright test tests/e2e/checkout-flow/

Coverage audit

The meow:review skill includes a test coverage audit (Step 4.75) that:

1. Traces code paths through your changes
2. Maps user flows to test scenarios
3. Identifies untested paths
4. Auto-generates tests for gaps

Next workflow

→ QA Testing — manual QA with structured reports