swift-concurrency

Swift 6 migration requires analyzing project build settings and isolation boundaries to identify safe refactors. This Skill diagnoses compiler diagnostics related to async/await and Sendable rules, then recommends code changes that preserve structured concurrency safety.

Actor isolation protects state from data races by restricting access to its methods. When using async/await, crossing isolation boundaries requires await points, and this Skill helps diagnose threading behavior and main-actor isolation issues within your Swift codebase.

Sendable errors occur when non-thread-safe types cross concurrency boundaries. This Skill diagnoses Sendable rule violations by analyzing your types and isolation boundaries, providing safe refactoring recommendations to ensure strict concurrency compliance.

Testing async behavior requires specific patterns to validate task groups and avoid retain cycles. This Skill provides testing patterns for async workflows, helps reduce suspension-point overhead, and offers performance tuning recommendations for real projects.

Main-actor isolation issues arise when async tasks incorrectly cross threading boundaries. This Skill diagnoses main-actor isolation problems by reasoning about isolation boundaries and suspension points, recommending safe refactors that preserve structured concurrency.

Refactoring async code for Swift 6 involves identifying build settings, isolation boundaries, and Sendable compliance. This Skill evaluates your concurrency structure and recommends the safest code changes to make first during your migration process.