recyclarr/src/Trash/LogJanitor.cs

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

namespace Trash
{
    public class LogJanitor : ILogJanitor
    {
        private readonly IFileSystem _fileSystem;

        public LogJanitor(IFileSystem fileSystem)
        {
            _fileSystem = fileSystem;
        }

        public void DeleteOldestLogFiles(int numberOfNewestToKeep)
        {
            foreach (var file in _fileSystem.DirectoryInfo.FromDirectoryName(AppPaths.LogDirectory).GetFiles()
                .OrderByDescending(f => f.Name)
                .Skip(numberOfNewestToKeep))
            {
                file.Delete();
            }
        }
    }
}