How does this skill handle mocking and dependency injection?

It follows Martin Fowler's taxonomy of test doubles, preferring 'SpyingStubs' and state verification over brittle behavior verification, with doubles placed close to their protocols using #if DEBUG guards.

Can I use this for UI and Integration testing?

Yes, the skill includes specific patterns for integration testing between modules and snapshot testing for UI regression using the SnapshotTesting library.

What are the F.I.R.S.T. principles it follows?

The skill ensures tests are Fast, Isolated, Repeatable, Self-Validating, and Timely, ensuring your CI/CD pipeline remains stable and efficient.

Does this skill support XCTest?

While the skill provides comprehensive migration paths from XCTest, its primary focus is implementing the modern Swift Testing framework (@Test, #expect) for improved performance and readability.

Swift Testing Expert

Name: Swift Testing Expert
Author: bocato

bybocato

•

Mobile Development

Implements modern Swift Testing patterns and provides expert guidance on unit testing, mocks, and XCTest migrations for iOS and macOS development.

This skill empowers developers to transition to and master the modern Swift Testing framework, moving beyond legacy XCTest patterns. It provides a comprehensive framework for creating reliable test suites using best practices like the Arrange-Act-Assert pattern, F.I.R.S.T. principles, and a strict taxonomy of test doubles including Mocks, Spies, and Stubs. Whether you are setting up parameterized tests, handling complex async scenarios, or integrating snapshot testing, this skill ensures your test code is as robust and maintainable as your production code by placing fixtures and doubles directly near their interfaces.

Key Features

01Guidance on placing fixtures and test doubles using #if DEBUG for better modularity

02Strict enforcement of Arrange-Act-Assert (AAA) and F.I.R.S.T. testing principles

0367 GitHub stars

04Support for advanced patterns like parameterized testing and async/await confirmations

05Automated guidance for migrating legacy XCTest suites to modern Swift Testing syntax

06Standardized implementation of test doubles including Spies, Stubs, and Mocks

Use Cases

01Modernizing an existing iOS codebase by migrating from XCTest to Swift Testing

02Implementing data-driven testing scenarios using parameterized tests for edge-case validation

03Creating deterministic unit tests for complex async business logic and network calls

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add bocato/swift-testing-agent-skill swift-testing

For use in Claude.ai and ChatGPT

Download Skill