Swift Concurrency patterns — async/await, actors, tasks, Sendable conformance. Use when writing async/await code, implementing actors, working with structured concurrency, or ensuring data race safety.
85
78%
Does it follow best practices?
Impact
97%
1.02xAverage score across 3 eval scenarios
Passed
No known issues
Optimize this skill with Tessl
npx tessl skill review --optimize ./skills/framework/swift-concurrency/SKILL.mdActor isolation and Sendable conformance
Actor for registry
100%
100%
No NSLock/manual locks
100%
100%
No @unchecked Sendable on registry
100%
100%
Sendable JobRecord
100%
100%
Explicit Sendable on public/struct
100%
100%
Structured parallel workers
100%
100%
No nested Task in task group
100%
100%
Await required for actor access
100%
100%
No Task.detached for workers
100%
100%
Design notes explain actor choice
100%
100%
Correct concurrency boundary
100%
100%
Task cancellation and structured concurrency
Structured parallelism
100%
100%
No Task.detached
100%
100%
No nested Task in group
100%
100%
Cancellation check before stages
100%
100%
Cancellation check in loop
87%
50%
CancellationError propagates
100%
100%
Automatic child cancellation
100%
100%
Sendable types
100%
100%
Design doc explains cancellation
100%
100%
No unstructured task leaks
100%
100%
Async test patterns and dummy suspension avoidance
No dummy Task.yield in queue
100%
100%
Correct async on queue
100%
100%
No dummy yield in isDispatching
100%
100%
Actor not @unchecked Sendable class
100%
100%
No manual locking
100%
100%
Swift Testing preferred
0%
100%
No blocking wait(for:)
100%
100%
Correct async fulfillment or direct await
100%
100%
isDispatching test deterministic
60%
60%
Cancellation test present
100%
100%
Review notes explain dummy suspension fix
100%
100%
Review notes explain test fix
100%
100%
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