Test Implementation Patterns

Reference Selection

Test Type	Reference	When to Use
Unit / Integration	references/frontend.md	Implementing React component tests with RTL + Vitest + MSW
E2E	references/e2e.md	Implementing browser-level E2E tests with Playwright

Common Principles

AAA Structure

All tests follow Arrange-Act-Assert:

• Arrange: Set up preconditions and inputs
• Act: Execute the behavior under test
• Assert: Verify the expected outcome

Test Independence

• Each test runs independently without depending on other tests
• No shared mutable state between tests
• Deterministic execution — no random or time dependencies without mocking

Naming

• Test names describe expected behavior from user perspective
• One test verifies one behavior