I have a simple type:
public struct Location: Decodable {
public let coordinate: CLLocationCoordinate2D
public let speed: CLLocationSpeed
public let heading: CLLocationDirection
}
It has no public initializer, as it’s only ever created from network responses and my app has no need to create them directly. However, I do want to be able to test with preset values, so I have an extension in my test target:
extension Location {
init(coordinate: CLLocationCoordinate2D = .mine, speed: CLLocationSpeed = 30, heading: CLLocationDirection = 0) {
self.coordinate = coordinate
self.speed = speed
self.heading = heading
}
}
Under Swift 4.1, with 0189 in effect, I get the warning Initializer for struct 'Location' must use "self.init(...)" or "self = ..." because it is not in module 'Networking'. Without thinking I refactored to call the suggested self.init(...), self.init(coordinate: coordinate, speed: speed, heading: heading). Unfortunately, this is circular, leading to a crash. Even if I did have a public memberwise initializer, there would still be ambiguity.
What’s the solution here? Do I really need to maintain public initializers within my Networking framework that will only ever be used for testing? Could a change be made to prevent the warning when there are no public initializers? If nothing else, shouldn’t the warning message be different if the type has no public initializers at all?