Unit & Component Testing (Vitest + RTL) (Frontend Standard)

What to test

• Component rendering and behavior
• Accessibility basics (labels, roles, keyboard where relevant)
• Feature flows at the component boundary

What not to test

• Implementation details (private state, internal function calls) unless required

Mocking network

• UI code should call the BFF only. Mock BFF calls in tests at the fetch/client boundary (project-specific implementation).