Doug
33e7c1a819
Installed for Copilot with `gh skill install` and manually created a symlink for Claude to access all Copilot skills.
2.3 KiB
Hotspots
Search targets for concurrency review. When any of these appear in code, inspect carefully using the referenced rules.
DispatchQueue
In app-level code, DispatchQueue.main.async, DispatchQueue.global(), and custom serial queues usually have a Swift concurrency equivalent – see interop.md. However, GCD can still be appropriate in low-level libraries, framework interop, and performance-critical synchronous sections where queues or locks are the right tool. Check the context carefully before flagging.
Task.detached
Rarely correct. Usually means the author wanted background execution but should have used @concurrent (Swift 6.2) or a task group. Check whether shedding actor isolation and priority is truly intentional. See unstructured.md.
Task {} inside a loop
Frequently a bad idea – evaluate whether it should be a task group instead. See structured.md.
withCheckedContinuation / withCheckedThrowingContinuation
Audit every code path to ensure the continuation is resumed exactly once. Watch for early returns, thrown errors, and callbacks that might never fire. See bridging.md.
AsyncStream (closure-based initializer)
Prefer the modern AsyncStream.makeStream(of:) factory. If using the closure form, verify the continuation is finished in all cleanup paths. See async-streams.md.
@unchecked Sendable
Should be very rare. Check whether the type actually provides thread safety (internal locking, immutability). If it was added just to silence a compiler error, the real fix is usually an actor or value type. Check whether Swift 6 region-based isolation makes it unnecessary. See bridging.md.
MainActor.run {}
Often unnecessary. If the surrounding code is already @MainActor (explicitly or via default isolation), this is a no-op. If it's used to hop to the main actor from a background context, check whether the function should just be @MainActor instead.
Actors
Check for reentrancy bugs: any method that reads state, awaits, then writes state is suspect. See actors.md and bug-patterns.md.
Force unwraps after await inside actors
A ! on actor state after an await is a prime target for a latent crash, because another caller may have set the value to nil during the suspension. See bug-patterns.md.