shinpr/test-implement

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