Swift Testing Pro

{
  "name": "swift-testing-pro",
  "version": "1.0.0",
  "description": "Writes, reviews, and improves Swift Testing code using modern APIs and best practices.",
  "author": { "name": "Paul Hudson" },
  "homepage": "https://github.com/twostraws/Swift-Testing-Agent-Skill",
  "repository": "https://github.com/twostraws/Swift-Testing-Agent-Skill",
  "license": "MIT",
  "skills": "./skills/"
}


interface:
  display_name: "Swift Testing Pro"
  short_description: "Reviews Swift Testing code for modern best practices."
  icon_small: "./assets/swift-testing-pro-icon.svg"
  icon_large: "./assets/swift-testing-pro-icon.png"
  brand_color: "#3B9025"
  default_prompt: "Use $swift-testing-pro to review my project."

policy:
  allow_implicit_invocation: true

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# Async tests

Swift Testing is built to be async and run tests in parallel; special care must be taken to ensure those tests run well, particularly when Swift concurrency is involved. For more help with Swift concurrency, suggest the [Swift Concurrency Pro agent skill](https://github.com/twostraws/swift-concurrency-agent-skill).


## Serializing tests

The `serialized` trait allows tests to be run serially rather than in parallel, but it only works on parameterized tests. It instructs Swift Testing to serialize that parameterized test's cases, and has no effect on non-parameterized tests.

You can also apply `.serialized` to a whole test suite: it will cause all tests and sub-suites to be serialized.

**Important:** Most agents very strongly believe that `.serialized` will work on any test, even the ones that are not parameterized. They are wrong. It only works on parameterized tests.


## Confirming async work

When using `confirmation(expectedCount:)` to check that an async function has been executed a certain number of times, any tested code must have finished executing fully by the time the `confirmation()` closure finishes.

**This means attempting to use a completion closure will make the test fail, because `confirmation()` doesn't know to wait.**

For example, this code does some work inside a task, but there's no way to monitor it being completed:

```swift
struct Worker {
    func run(_ work: @escaping () -> Void) -> Task<Void, Never> {
        Task {
            let start = CFAbsoluteTimeGetCurrent()
            work()
            print("Elapsed:", CFAbsoluteTimeGetCurrent() - start)
        }
    }
}
```

That kind of code will not work well with `confirmation()`, because it will not u