DockKit Error Handling and Testing Patterns

func safeTrack(
    observations: [DockAccessory.Observation],
    cameraInfo: DockAccessory.CameraInformation,
    accessory: DockAccessory
) async {
    do {
        try await accessory.track(observations, cameraInformation: cameraInfo)
    } catch let error as DockKitError {
        switch error {
        case .notConnected:
            // Accessory disconnected, stop tracking loop
            break
        case .frameRateTooHigh:
            // Throttle observation delivery
            break
        case .frameRateTooLow:
            // Speed up frame processing
            break
        case .noSubjectFound:
            // No subject in observations, continue
            break
        default:
            break
        }
    } catch {
        // Unexpected error
    }
}

#if canImport(DockKit)
import DockKit
#endif

final class DockController {
    var isDockKitAvailable: Bool {
        #if canImport(DockKit)
        return true
        #else
        return false
        #endif
    }

    func startTracking() async {
        #if canImport(DockKit)
        do {
            for await stateChange in try DockAccessoryManager.shared.accessoryStateChanges {
                // Handle state changes
            }
        } catch {
            // DockKit not available on this device
        }
        #endif
    }
}

@Observable
final class MockDockViewModel {
    var isConnected = true
    var accessoryName: String? = "Mock DockKit Stand"
    var batteryLevel: Double? = 0.75
    var isCharging = false
    var trackingMode = "System"

    // Use in SwiftUI previews
    func simulateDisconnect() {
        isConnected = false
        accessoryName = nil
        batteryLevel = nil
    }
}