swift-testing-expert

The `swift-testing-expert` skill provides professional guidance for writing, reviewing, migrating, and debugging Swift tests using modern Swift Testing APIs. It addresses common challenges in Swift test development, including flaky tests, complex asynchronous patterns, and incremental migration from legacy XCTest suites. By emphasizing readable, maintainable, and robust tests, this skill helps developers ensure higher test quality while maintaining compatibility with Apple-platform and Swift server projects. It streamlines the testing workflow, allowing developers to focus on logic rather than boilerplate or fragile test structures.

Key features include guidance on using `#expect` and `#require` macros for assertions, leveraging traits and tags for test metadata, designing parameterized tests, managing parallel execution safely, handling async waiting patterns, and performing incremental XCTest migration. The skill also provides templates for triage within the first 60 seconds, a routing map for quickly finding reference documentation, and common pitfalls with actionable solutions. It enforces best practices such as importing `Testing` only in test targets, avoiding suite-level `@available` annotations, and promoting parameterization over repetitive test methods.

This skill is ideal for Swift developers, QA engineers, and software teams working on unit and integration tests for iOS, macOS, and server-side Swift applications. Use cases include writing new Swift tests, modernizing legacy XCTest suites, debugging flaky or nondeterministic failures, improving test maintainability and readability, and implementing efficient async test patterns. It is particularly useful for teams seeking to adopt a modern Swift Testing workflow while maintaining coexistence with existing XCTest infrastructure.