URL extension to create a directory in the iOS documents directory

urlExtension.swift

extension URL {
    static func createDirectory(_ dirName: String) -> URL? {
        let fileManager = FileManager.default
        if let documentDirectory = fileManager.urls(for: .documentDirectory, in: .userDomainMask).first {
            let dirPath = documentDirectory.appendingPathComponent(dirName)
            if !fileManager.fileExists(atPath: dirPath.path) {
                do {
                    try fileManager.createDirectory(atPath: dirPath.path,
                                                    withIntermediateDirectories: true,
                                                    attributes: nil)
                } catch {
                    print(error.localizedDescription)
                    
                    return nil
                }
            }
            
            return dirPath
        } else {
            return nil
        }
    }
}