Swift Testing Standards

Priority: P0

Implementation Guidelines

XCTest Framework

• Standard Naming: Prefix test methods with test (e.g., testUserLoginSuccessful).
• Setup/Teardown: Use setUpWithError() and tearDownWithError() for environment management.
• Assertions: Use specific assertions: XCTAssertEqual, XCTAssertNil, XCTAssertTrue, etc.

Async Testing

• Async/Await: Mark test methods as async and use await directly inside them.
• Expectations: Use XCTestExpectation for callback-based or delegate-based async logic.
• Timeout: Always set reasonable timeouts for expectations to avoid hanging CI.

Test Organization

• Unit Tests: Focus on logic isolation using mocks/stubs for dependencies.
• UI Tests: Test user flows using XCUIApplication and accessibility identifiers.
• Coverage: Aim for high coverage on critical business logic and state transitions.

Anti-Patterns

• Thread Sleeps: **No Thread.sleep**: Use expectations or await.
• Force Unwrapping in Tests: **No user!**: Use XCTUnwrap(user) for better failure messages.
• Missing Assertions: **Tests must assert**: A test that only runs code is not a test.

References

• XCTest Patterns & Async Tests