Testing

Unit and Component Tests

Jest runs unit tests with react-native preset mocking native modules. React Native Testing Library queries by accessibility role and text like users do.

Mock navigation with NavigationContainer test helpers. Fake timers test debounced search inputs.

Snapshot tests catch unintended UI regressions but review diffs carefully—prefer behavioral assertions.

• Use testID only when accessibility queries insufficient
• Reset mocks in beforeEach
• Run tests on CI matching local jest config

import { render, screen, fireEvent } from '@testing-library/react-native';

test('submits form', () => {
  render(<LoginScreen />);
  fireEvent.changeText(screen.getByLabelText('Email'), 'a@b.com');
  fireEvent.press(screen.getByText('Sign in'));
  expect(screen.getByText('Welcome')).toBeTruthy();
});

E2E Testing

Detox drives gray-box tests on simulators with synchronization. Maestro uses YAML flows readable by QA.

E2E covers login, purchase, and critical paths. Keep suites small and reliable—flaky E2E blocks releases.

Seed staging backends for deterministic assertions; avoid production E2E writes.

• Run E2E on release builds periodically
• Parallelize by platform in CI matrices
• Capture screenshots and videos on failure