AwaitNotCompletionHandler [rule] v0.1.0

New async APIs are written as func f(...) async throws -> T. The call site reads as straight-line code, errors propagate through try, cancellation propagates through the cooperative cancellation system, and the structured-concurrency model (Task, TaskGroup, async let) composes naturally. Completion-handler APIs ((Result<T, E>) -> Void callbacks) are reserved for two cases: (1) wrapping platform APIs that have not yet adopted async, and (2) interop with Objective-C code that calls back via blocks.

Checks

• New public async functions are declared async (and async throws if they can fail), not as completion-handler-taking functions.
• Existing completion-handler callers are migrated by introducing an async overload via withCheckedThrowingContinuation or withCheckedContinuation, then deprecating the callback form.
• Long-running work creates a Task; tasks owned by a UI object are tracked so they can be cancelled in deinit or on view disappearance.
• Multiple parallel async operations use async let or TaskGroup, not nested completion handlers.
• Cancellation is checked at appropriate suspension points (try Task.checkCancellation() inside long loops); long-running synchronous work is broken up with await Task.yield() so cancellation can take effect.

Label

Expose async work as async functions; use completion handlers only at non-Swift boundaries

AwaitNotCompletionHandler [rule] v0.1.0

New async APIs are written as func f(...) async throws -> T. The call site reads as straight-line code, errors propagate through try, cancellation propagates through the cooperative cancellation system, and the structured-concurrency model (Task, TaskGroup, async let) composes naturally. Completion-handler APIs ((Result<T, E>) -> Void callbacks) are reserved for two cases: (1) wrapping platform APIs that have not yet adopted async, and (2) interop with Objective-C code that calls back via blocks.

Checks

• New public async functions are declared async (and async throws if they can fail), not as completion-handler-taking functions.
• Existing completion-handler callers are migrated by introducing an async overload via withCheckedThrowingContinuation or withCheckedContinuation, then deprecating the callback form.
• Long-running work creates a Task; tasks owned by a UI object are tracked so they can be cancelled in deinit or on view disappearance.
• Multiple parallel async operations use async let or TaskGroup, not nested completion handlers.
• Cancellation is checked at appropriate suspension points (try Task.checkCancellation() inside long loops); long-running synchronous work is broken up with await Task.yield() so cancellation can take effect.

Label

Expose async work as async functions; use completion handlers only at non-Swift boundaries

Label

Expose async work as async functions; use completion handlers only at non-Swift boundaries