Swift Testing Code Review

---
name: swift-testing-code-review
description: Reviews Swift Testing code for proper use of #expect/#require, parameterized tests, async testing, and organization. Use when reviewing .swift files with import Testing, @Test, #expect, @Suite, or confirmation patterns.
---

# Swift Testing Code Review

## Quick Reference

| Issue Type | Reference |
|------------|-----------|
| #expect vs #require, expression capture, error testing | [references/expect-macro.md](references/expect-macro.md) |
| @Test with arguments, traits, zip() pitfalls | [references/parameterized.md](references/parameterized.md) |
| confirmation, async sequences, completion handlers | [references/async-testing.md](references/async-testing.md) |
| @Suite, tags, parallel execution, .serialized | [references/organization.md](references/organization.md) |

## Review Checklist

- [ ] Expressions embedded directly in `#expect` (not pre-computed booleans)
- [ ] `#require` used only for preconditions, `#expect` for assertions
- [ ] Error tests check specific types (not generic `(any Error).self`)
- [ ] Parameterized tests with pairs use `zip()` (not Cartesian product)
- [ ] No logic mirroring implementation in parameterized expected values
- [ ] Async sequences tested with `confirmation(expectedCount:)`
- [ ] Completion handlers use `withCheckedContinuation`, not `confirmation`
- [ ] `.serialized` applied only where necessary (shared resources)
- [ ] Sibling serialized suites nested under parent if mutually exclusive
- [ ] No assumption of state persistence between `@Test` functions
- [ ] Disabled tests have explanations and bug links

## When to Load References

- Reviewing #expect or #require usage -> expect-macro.md
- Reviewing @Test with arguments or traits -> parameterized.md
- Reviewing confirmation or async testing -> async-testing.md
- Reviewing @Suite or test organization -> organization.md

## Review Questions

1. Could pre-computed booleans in `#expect` lose diagnostic context?
2. Is `#require` stopping tests prematurely instead of revealing all failures?
3. Are multi-argument parameterized tests creating accidental Cartesian products?
4. Could `zip()` silently drop test cases due to unequal array lengths?
5. Are completion handlers incorrectly tested with `confirmation`?