iOS swift FileManager remove/delete file only if it exists. "No such file or directory" fix.

FileManager+RemoveIfExists.swift

// Most implementations first check if the file exists, and then do the remove.
// This is subject to race conditions and requires accessing the file system twice.
// A better solution is to ignore that particular exception.

extension FileManager {
    func removeItemIfExists(at url: URL) throws {
        func isDoesNotExist(error: NSError) -> Bool {
            return error.domain == NSPOSIXErrorDomain && error.code == ENOENT
        }
        
        func isFailedToRemove(error: NSError) -> Bool {
            return error.domain == NSCocoaErrorDomain && error.code == 4
        }
        
        do {
            try removeItem(at: url)
        }
        catch let error as NSError {
            if isFailedToRemove(error: error),
               let underlying = error.userInfo[NSUnderlyingErrorKey] as? NSError,
               isDoesNotExist(error: underlying)
            {
                // ignore. The file didn't exist.
            }
            else {
                // a different error which should be handled
                throw error
            }
        }
    } 
}