Chapter.Net.FileSystems Library

Overview

Chapter.Net.FileSystems is a library that provides helper classes for working with the file system, offering convenient abstractions that are also ideal for unit testing scenarios.

Features

• IDirectory: Gives access to all static Directory.* methods.
• IFile: Gives access to all static File.* methods.
• IPath: Gives access to all static Path.* methods.
• IFileSystem: Gives simple access to the IDirectory, IFile and IPath.
• Directory Extension: Provides extensions to the Directory accessible directly or by using the IDirectory.

Getting Started

1. Installation:

   • Install the Chapter.Net.FileSystems library via NuGet Package Manager:

   dotnet add package Chapter.Net.FileSystems

2. IDirectory:

   • Usage

   public class ViewModel : ObservableObject
   {
       private readonly IDirectory _directory;
   
       public ViewModel(IDirectory directory)
       {
           _directory = directory;
       }
   
       public string GetLogFolder()
       {
           var directory = @".\Logs";
           if (!_directory.Exists(directory))
               _directory.CreateDirectory(directory);
           return directory;
       }
   }
   
   [TestFixture]
   public class ViewModelTests
   {
       private Mock<IDirectory> _directory;
       privaze ViewModel _target;
   
       [SetUp]
       public void Setup()
       {
           _directory = new Mock<IDirectory>();
   
           _target = new ViewModel(_directory.Object);
       }
   
       [Test]
       public void GetLogFolder_SubFolderDoesNotExists_CreatesIt()
       {
           _directory.Setup(x => x.Exists(Args.Any<string>())).Returns(false);
   
           var result = _target.GetLogFolder();
   
           _directory.Verify(x => x.CreateDirectory(result), Times.Once);
           Assert.That(result, Is.EqualTo(@".\Logs");
       }
   
       [Test]
       public void GetLogFolder_SubFolderExists_DoesNotCreatIt()
       {
           _directory.Setup(x => x.Exists(Args.Any<string>())).Returns(true);
   
           var result = _target.GetLogFolder();
   
           _directory.Verify(x => x.CreateDirectory(result), Times.Never);
           Assert.That(result, Is.EqualTo(@".\Logs");
       }
   }

3. IFile:

   • Usage

   public class ViewModel : ObservableObject
   {
       private readonly IFile _file;
   
       public ViewModel(IFile file)
       {
           _file = file;
       }
   
       public void CopyTo(string destinationPath)
       {
           var file = @".\Settings.xml";
           if (_file.Exists(file))
               _file.Copy(file, destinationPath);
       }
   }
   
   [TestFixture]
   public class ViewModelTests
   {
       private Mock<IFile> _file;
       privaze ViewModel _target;
   
       [SetUp]
       public void Setup()
       {
           _file = new Mock<IFile>();
   
           _target = new ViewModel(_file.Object);
       }
   
       [Test]
       public void CopyTo_FileExists_CopiesIt()
       {
           _file.Setup(x => x.Exists(Args.Any<string>())).Returns(true);
   
           var result = _target.CopyTo("Destination");
   
           _file.Verify(x => x.Copy(Args.Any<string>(), "Destination"), Times.Once);
       }
   
       [Test]
       public void CopyTo_FileDoesNotExist_DoesNotCopyIt()
       {
           _file.Setup(x => x.Exists(Args.Any<string>())).Returns(false);
   
           var result = _target.CopyTo("Destination");
   
           _file.Verify(x => x.Copy(Args.Any<string>(), "Destination"), Times.Never);
       }
   }

4. IPath:

   • Usage

   public class ViewModel : ObservableObject
   {
       private readonly IDirectory _directory;
       private readonly IPath _path;
   
       public ViewModel(IDirectory directory, IPath path)
       {
           _directory = directory;
           _path = path;
       }
   
       public string GetRelativeTo(string path)
       {
           var currentDir = _directory.GetCurrentDirectory();
           return _path.GetRelativePath(currentDir, path);
       }
   }
   
   [TestFixture]
   public class ViewModelTests
   {
       private Mock<IDirectory> _directory;
       private Mock<IPath> _path;
       privaze ViewModel _target;
   
       [SetUp]
       public void Setup()
       {
           _directory = new Mock<IDirectory>();
           _path = new Mock<IPath>();
   
           _target = new ViewModel(_directory.Object, _path.Object);
       }
   
       [Test]
       public void GetRelativeTo_SubFolder_CreatesRelative()
       {
           _directory.Setup(x => x.GetCurrentDirectory()).Returns(@"C:\MyFolder");
           _path.Setup(x => x.GetRelativePath(@"C:\MyFolder", @"C:\SomethingElse")).Returns(@"..\SomethingElse");
   
           var result = _target.GetRelativeTo(@"C:\SomethingElse");
   
           Assert.That(result, Is.EqualTo(@"..\SomethingElse");
       }
   }

5. IFileSystem:

   • Usage

   public class ViewModel : ObservableObject
   {
       private readonly IFileSystem _fileSystem;
   
       public ViewModel(IFileSystem fileSystem)
       {
           _fileSystem = fileSystem;
       }
   
       public string GetRelativeTo(string path)
       {
           var currentDir = _fileSystem.Directory.GetCurrentDirectory();
           return _fileSystem.Path.GetRelativePath(currentDir, path);
       }
   }
   
   [TestFixture]
   public class ViewModelTests
   {
       private Mock<IFileSystem> _fileSystem;
       private Mock<IDirectory> _directory;
       private Mock<IPath> _path;
       privaze ViewModel _target;
   
       [SetUp]
       public void Setup()
       {
           _directory = new Mock<IDirectory>();
           _path = new Mock<IPath>();
           _fileSystem = new Mock<IFileSystem>();
           _fileSystem.Setup(x => x.File).Returns(_directory.Object);
           _fileSystem.Setup(x => x.Path).Returns(_path.Object);
   
           _target = new ViewModel(_fileSystem.Object);
       }
   
       [Test]
       public void GetRelativeTo_SubFolder_CreatesRelative()
       {
           _directory.Setup(x => x.GetCurrentDirectory()).Returns(@"C:\MyFolder");
           _path.Setup(x => x.GetRelativePath(@"C:\MyFolder", @"C:\SomethingElse")).Returns(@"..\SomethingElse");
   
           var result = _target.GetRelativeTo(@"C:\SomethingElse");
   
           Assert.That(result, Is.EqualTo(@"..\SomethingElse");
       }
   }

6. Directory Extension:

   • Usage

   public class ViewModel : ObservableObject
   {
       public void EnsureCopied(string destination)
       {
           if (!Directory.Exists(destination))
               DirectoryEx.Copy(@"C:\MyData", destination);
       }
   }

Links

• NuGet
• GitHub

License

Copyright (c) David Wendland. All rights reserved. Licensed under the MIT License. See LICENSE file in the project root for full license information.