/// A type that interfaces with the local file system.
protocol FileServicing: Sendable {
    
    // MARK: Functions
    
    /// Lists the names of items located at a given folder path. in the local file system.
    /// - Parameter folder: A path to a folder that could be found in the local file system.
    /// - Returns: A list of names related to the items retrieved from a given folder path.
    /// - Throws: A ``FileServiceError`` error type in case any error happens while retrieving the list.
    func listItems(in folder: String) async throws (FileServiceError) -> [String]
    
}

// MARK: - Errors

/// A representation of all possible errors that could be returned by the type conforming to the ``FileServicing`` protocol.
enum FileServiceError: Error {
    /// A given folder path is empty.
    case folderPathEmpty
    /// A given folder path is not actually a directory.
    case folderNotDirectory
    /// A given folder path has not been found in the file system.
    case folderNotFound
    /// Captures any other error found while executing a file service operation.
    case other(Error)
}