Kavita/API/Extensions/ZipArchiveExtensions.cs

using System.IO;
using System.IO.Compression;
using System.Linq;

namespace API.Extensions
{
    public static class ZipArchiveExtensions
    {
        /// <summary>
        /// Checks if archive has one or more files. Excludes directory entries. 
        /// </summary>
        /// <param name="archive"></param>
        /// <returns></returns>
        public static bool HasFiles(this ZipArchive archive)
        {
            return archive.Entries.Any(x => Path.HasExtension(x.FullName));
        }
    }
}