Support named assets via enum values (to avoid string literals).

Image+Assets.swift

import Foundation
import SwiftUI

/// Extend Image with named assets
extension Image {
    
    enum Assets: String, RawRepresentable {
        case appButtonImage
        /// Place all your color assets here...the enum case should equal to the name you use in your Asset library
    }
    
    init(asset: Image.Assets) {
        self.init(asset.rawValue)
    }
}

/// Extend UIImage with named assets
extension UIImage {
    convenience init(asset: Image.Assets) {
        // Force unwrap okay because we are sure that Image.Assets are available
        self.init(named: asset.rawValue)!
    }
}

/// In use...
let image = Image(asset: .appButtonImage)
let uiImage = UIImage(asset: .appButtonImage)