custom enum errors with localizedDescription

customErrors.swift

// sepcifiy your errors
enum MyCustomError : Error {
    case customError
    case missingProperty
    
    var localizedDescription: String {
        switch self {
        case .urlCouldNotBeCreated:
            return NSLocalizedString("MyCustomErrorCcustomError", value: "a localized error message", comment: "")
        case .missingProperty:
            return NSLocalizedString("MyCustomErrorMissingProperty", value: "Missing coordinates", comment: "")
        }
    }
}

// use your error
func demo() throws {
    throw MyCustomError.customError
}

// catch your error
do {
    try demo()
} catch let error as MyCustomError {
    print(error.localizedDescription)	
}

Hi,
According to https://github.com/apple/swift-evolution/blob/master/proposals/0112-nserror-bridging.md
You need something like:

enum MyCustomError : LocalizedError {
    case customError
    case missingProperty
    
    var errorDescription: String? {
        switch self {
        case .urlCouldNotBeCreated:
            return NSLocalizedString("MyCustomErrorCcustomError", value: "a localized error message", comment: "")
        case .missingProperty:
            return NSLocalizedString("MyCustomErrorMissingProperty", value: "Missing coordinates", comment: "")
        }
    }
}