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

namespace DotNetLs
{
    class Program
    {
        static void Main(string[] args)
        {
            string path = Directory.GetCurrentDirectory();
            bool showHidden = false;
            bool detailed = false;

            // Parse command-line arguments
            foreach (var arg in args)
            {
                if (arg == "-a")
                {
                    showHidden = true;
                }
                else if (arg == "-l")
                {
                    detailed = true;
                }
                else
                {
                    path = arg; // assume the last argument is the path
                }
            }

            try
            {
                var files = Directory.GetFileSystemEntries(path);

                foreach (var file in files)
                {
                    var fileInfo = new FileInfo(file);
                    if (!showHidden && fileInfo.Attributes.HasFlag(FileAttributes.Hidden))
                    {
                        continue; // skip hidden files
                    }

                    if (detailed)
                    {
                        Console.WriteLine($"{fileInfo.Attributes} {fileInfo.Length} bytes {fileInfo.LastWriteTime} {fileInfo.Name}");
                    }
                    else
                    {
                        Console.WriteLine(fileInfo.Name);
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error: {ex.Message}");
            }
        }
    }
}

dotnet new xunit -n DotNetLs.Tests
cd DotNetLs.Tests
dotnet add reference ../DotNetLs/DotNetLs.csproj

using System;
using System.IO;
using Xunit;

namespace DotNetLs.Tests
{
    public class LsTests
    {
        [Fact]
        public void TestListFiles()
        {
            // Arrange
            string testDir = Path.Combine(Directory.GetCurrentDirectory(), "TestDir");
            Directory.CreateDirectory(testDir);
            File.Create(Path.Combine(testDir, "file1.txt")).Dispose();
            File.Create(Path.Combine(testDir, ".hiddenfile")).Dispose();

            // Act
            var output = RunLsCommand(testDir);

            // Assert
            Assert.Contains("file1.txt", output);
            Assert.DoesNotContain(".hiddenfile", output); // Without -a option
        }

        [Fact]
        public void TestListAllFiles()
        {
            // Arrange
            string testDir = Path.Combine(Directory.GetCurrentDirectory(), "TestDir");
            Directory.CreateDirectory(testDir);
            File.Create(Path.Combine(testDir, "file1.txt")).Dispose();
            File.Create(Path.Combine(testDir, ".hiddenfile")).Dispose();

            // Act
            var output = RunLsCommand(testDir, "-a");

            // Assert
            Assert.Contains("file1.txt", output);
            Assert.Contains(".hiddenfile", output); // With -a option