Swift Testing Code Review

Quick Reference

Issue Type Reference

#expect vs #require, expression capture, error testing references/expect-macro.md

@Test with arguments, traits, zip() pitfalls references/parameterized.md

confirmation, async sequences, completion handlers references/async-testing.md

@Suite, tags, parallel execution, .serialized 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

• Could pre-computed booleans in #expect lose diagnostic context?

• Is #require stopping tests prematurely instead of revealing all failures?

• Are multi-argument parameterized tests creating accidental Cartesian products?

• Could zip() silently drop test cases due to unequal array lengths?

• Are completion handlers incorrectly tested with confirmation ?