swift-concurrency

Resolve Swift concurrency errors by analyzing compiler diagnostics and isolation boundaries to apply minimal safe code changes, such as isolating callers, introducing actors, or using MainActor.run. This process ensures behavior-preserving fixes for data races and Sendable conformance issues.

Migrate to Swift 6 by validating Sendable conformance and resolving isolation boundary issues across modules. The process provides a validation loop with specific build and test commands to ensure your async/await and TaskGroup usage remains safe and behavior-preserving.

Sendable conformance warnings occur when types cross actor isolation boundaries unsafely. Resolve them by applying @unchecked or @preconformance conformance with documented invariants, or by refactoring the types to meet strict Swift concurrency safety requirements.

Determine isolation boundaries by analyzing how @MainActor, custom actors, and nonisolated contexts interact in your source code. The correct approach recommends the smallest behavior-preserving change, such as isolating the caller or creating Data Access Objects.

Yes, the skill analyzes SwiftLint concurrency warnings and compiler diagnostics across files or modules. It captures exact offending symbols and required project build settings before suggesting migration-sensitive fixes for your codebase.

Use @unchecked Sendable only when you can document and guarantee specific thread-safety invariants manually. Apply it as a last resort when refactoring isolation boundaries or introducing actors is not feasible without breaking existing behavior.