ErrorThrowsNotResultWherePossible [rule] v0.1.0

Swift has two error-handling shapes: throwing functions (func f() throws -> T, func f() async throws -> T) and Result<Success, Failure>. The throwing form is the language-level mechanism — it integrates with try/catch, with async/await, and with typed-throws (Swift 6). Use it for any function whose call site immediately handles or propagates the error. Reserve Result for cases where the error must be stored alongside the value: callback bridges that cannot be made async, completion handlers from older APIs, or stream events that emit successes and failures over time.

Checks

• New functions that can fail are declared throws (or async throws), not -> Result<T, E>.
• Errors thrown are typed: a meaningful enum (enum NetworkError: Error { ... }) per failure mode, not NSError or String-shaped errors.
• When wrapping a callback API at a module boundary, convert it to async throws via withCheckedThrowingContinuation rather than exposing Result outwards.
• Result is used only when the error must be carried as a value: stored in a property, sent through a publisher, paired with a completion handler that predates async.

Label

Use throws for synchronous and async failure; reserve Result for stored values and bridges

ErrorThrowsNotResultWherePossible [rule] v0.1.0

Swift has two error-handling shapes: throwing functions (func f() throws -> T, func f() async throws -> T) and Result<Success, Failure>. The throwing form is the language-level mechanism — it integrates with try/catch, with async/await, and with typed-throws (Swift 6). Use it for any function whose call site immediately handles or propagates the error. Reserve Result for cases where the error must be stored alongside the value: callback bridges that cannot be made async, completion handlers from older APIs, or stream events that emit successes and failures over time.

Checks

• New functions that can fail are declared throws (or async throws), not -> Result<T, E>.
• Errors thrown are typed: a meaningful enum (enum NetworkError: Error { ... }) per failure mode, not NSError or String-shaped errors.
• When wrapping a callback API at a module boundary, convert it to async throws via withCheckedThrowingContinuation rather than exposing Result outwards.
• Result is used only when the error must be carried as a value: stored in a property, sent through a publisher, paired with a completion handler that predates async.

Label

Use throws for synchronous and async failure; reserve Result for stored values and bridges

Label

Use throws for synchronous and async failure; reserve Result for stored values and bridges