ios-testing

Unit tests in Swift use XCTest to validate models and services deterministically. Create an XCTestCase subclass, write test methods that arrange inputs, act on your code, and assert expected outputs. XCTest runs these tests fast and isolated, catching regressions early without UI dependencies.

Yes, XCTest supports UI testing for SwiftUI and UIKit components. Write UI tests that interact with your app as a user would—tapping buttons, entering text, verifying screen state. ViewInspector integrates with XCTest to inspect view hierarchies and validate rendering reliably.

Protocol-based mocks replace real services with controlled test doubles. Define your service as a protocol, create mock implementations that return predictable results, and inject them into your code under test. This approach handles async operations and error scenarios without making real network calls.

Structure tests across layers: unit tests for credential validation logic, mocks for authentication services, and UI tests for the login screen interaction. Combine test scaffolding for setup, mock services for network isolation, and UI verification to validate the full user journey end-to-end.

XCTest is the native testing framework for all Swift projects in Xcode and works with UIKit, SwiftUI, and mixed codebases. It provides unit test capabilities for both, and UI testing tools that interact with either framework's components.