everyone. I am new to Swift, and trying to handle custom errors in my project. Unfortunately, during errors I always encounter print(“DEBUG: Unknown error occurred: …”). For example, if error is ‘invalidURL’ I have ‘DEBUG: Unknown error occurred: A server with the specified hostname could not be found.’ and so on.

Any ideas how i can make it work? Thank you in advance.

Here is my function from DataService:

func getEnemy() async throws -> Enemy {

        guard let url = URL(string: urlString) else {
            throw EnemyAPIError.invalidURL
        }
        
        let (data, response) = try await urlSession.data(for: url)
        
        guard let httpResponse = response as? HTTPURLResponse else {
            print("DEBUG: Bad Server Response")
            throw EnemyAPIError.badServerResponse
        }
        
        guard httpResponse.statusCode == 200 else {
            print("DEBUG: Failed to fetch with status code: (httpResponse.statusCode)")
            throw EnemyAPIError.invalidStatusCode(statusCode: httpResponse.statusCode)
        }
        
        guard !data.isEmpty else {
            throw EnemyAPIError.invalidData
        }
        
        let enemy = try JSONDecoder().decode(Enemy.self, from: data)
        return enemy
    }

In my viewModel I am trying to handle custom errors:

func fetchEnemyAsync() async  {
do{
self.enemy = try await networkService.getEnemy()
} catch let error as EnemyAPIError {
self.errorMessage = error.customDescription
print("DEBUG: Error occurred: (error.customDescription)")
}
catch {
print("DEBUG: Unknown error occurred: (error.localizedDescription)")
self.errorMessage = "(error.localizedDescription)"
}
}

My custom errors:

enum EnemyAPIError: Error{
case invalidData
case invalidURL
case jsonParsingFailure
case badServerResponse
case requestFailed(description: String)
case invalidStatusCode(statusCode: Int)
case unknownError(error: Error)

    var customDescription: String {
        switch self {
        case .invalidData:
            return "Invalid data"
        case .invalidURL:
            return "Invalid URL"
        case .jsonParsingFailure:
            return "Failed to parse JSON"
        case .badServerResponse:
            return "Bad Server Response"
        case .requestFailed(let description):
            return "Request failed: (description)"
        case .invalidStatusCode(let statusCode):
            return "Invalid status code: (statusCode)"
        case .unknownError(let error):
            return "(error.localizedDescription)"
        }
    }

}

In my viewModel i’ve tried to handle errors like this, but it doesn’t work. I thought, it will catch any error of type EnemyAPIError.

func fetchEnemyAsync() async  {
do{
self.enemy = try await networkService.getEnemy()
} catch let error as EnemyAPIError {
self.errorMessage = error.customDescription
print("DEBUG: Error occurred: (error.customDescription)")
}