React 18 Enzyme → RTL Migration

Enzyme has no React 18 adapter and no React 18 support path. All Enzyme tests must be rewritten using React Testing Library.

The Philosophy Shift (Read This First)

Enzyme tests implementation. RTL tests behavior.

// Enzyme: tests that the component has the right internal state
expect(wrapper.state('count')).toBe(3);
expect(wrapper.instance().handleClick).toBeDefined();
expect(wrapper.find('Button').prop('disabled')).toBe(true);

// RTL: tests what the user actually sees and can do
expect(screen.getByText('Count: 3')).toBeInTheDocument();
expect(screen.getByRole('button', { name: /submit/i })).toBeDisabled();