Question

我有以下代码用于从Zip添加/解压缩。我正在尝试重构这个以使其准备好测试。有人可以提供我如何实现这一目标的指示吗？旁白：我使用Moq作为我的模拟框架，使用MSTest作为我的单元测试工具

private const long BufferSize = 4096;

public static void ExtractZip(string zipFilename, string folder) {
  using (var zip = System.IO.Packaging.Package.Open(zipFilename, FileMode.OpenOrCreate)) {
    foreach (var part in zip.GetParts()) {
      using (var reader = new StreamReader(part.GetStream(FileMode.Open, FileAccess.Read))) {
        using (var writer = new FileStream(folder + "\\" + Path.GetFileName(part.Uri.OriginalString),
                                           FileMode.Create, FileAccess.Write)) {
          var buffer = System.Text.Encoding.UTF8.GetBytes(reader.ReadToEnd());
          writer.Write(buffer, 0, buffer.Length);
        }
      }
    }
  }
}

public static void AddFileToZip(string zipFilename, string fileToAdd) {
  using (var zip = System.IO.Packaging.Package.Open(zipFilename, FileMode.OpenOrCreate)) {
    var destFilename = ".\\" + Path.GetFileName(fileToAdd);
    var uri = PackUriHelper.CreatePartUri(new Uri(destFilename, UriKind.Relative));
    if (zip.PartExists(uri)) {
      zip.DeletePart(uri);
    }
    var part = zip.CreatePart(uri, "", CompressionOption.Normal);
    using (var fileStream = new FileStream(fileToAdd, FileMode.Open, FileAccess.Read)) {
      using (var dest = part.GetStream()) {
        CopyStream(fileStream, dest);
      }
    }
  }
}

提前致谢。

Answer 1

我会制作这两个静态方法（ExtractZip和AddFileToZip）实例方法，并将其放入一个接口：

public interface IZipper
{
  void ExtractZip(string zipFilename, string folder);
  void AddFileToZip(string zipFilename, string fileToAdd);
}

public class Zipper : IZipper
{
  public void ExtractZip(string zipFilename, string folder)
  { 
    //...
  }

  void AddFileToZip(string zipFilename, string fileToAdd)
  {
    //...
  }
}


// client code
class Foo
{
  private IZipper myZipper;
  // gets an instance of the zipper (injection), but implements only 
  // against the interface. Allows mocks on the IZipper interface.
  public Foo(IZipper zipper)
  {
    myZipper = zipper;
  }

}

客户端代码现在很容易测试。

拉链类怎么样？

考虑是否值得测试。
在我们的项目中，我们区分单元测试（隔离）和集成测试，可以使用数据库或文件系统。您可以将其声明为“文件系统集成测试”。当然，只允许使用测试目标文件夹。这不应该有任何问题。
考虑将文件操作移出，并仅使用流。然后，您可以轻松地测试内存流上的压缩。文件操作仍然需要在某处，而不是经过测试。

Answer 2

摘要FileStream在IStreamProvider后面的创建，并将其传递给AddFileToZip和ExtractZip。除非您愿意在进行单元测试时执行磁盘IO，否则您将不得不抽象文件系统操作。

Answer 3

我在这里粘贴最终代码，因为它可能对某人有所帮助，也让我得到反馈。感谢Stefan指出我正确的方向。



/// <summary>
/// The commented methods are marked for future
/// </summary>
public interface IZipper
{
    //void Create();
    void ExtractAll();
    void ExtractAll(string folder);
    //void Extract(string fileName);
    void AddFile(string fileName);
    //void DeleteFile(string fileName);
}
public interface IZipStreamProvider
{
    Stream GetStream(string fileName);
}

public class ZipStreamProvider : IZipStreamProvider
{
    public Stream GetStream(string fileName)
    {
        //Create a read/writable file
        return new FileStream(fileName, FileMode.Create);
    }
}

public class Zipper : IZipper
{
    private const long BufferSize = 4096;
    public string ZipFileName { get; set;}

    //seam.. to use property injection
    private IZipStreamProvider ZipStreamProvider { get; set;}

    public Zipper(string zipFilename)
    {
        ZipFileName = zipFilename;
        //By default, write to file
        ZipStreamProvider = new ZipStreamProvider();
    }

    public void ExtractAll()
    {
        ExtractAll(Environment.CurrentDirectory);
    }

    public void ExtractAll(string folder)
    {
        using (var zip = System.IO.Packaging.Package.Open(ZipStreamProvider.GetStream(ZipFileName)))
        {
            foreach (var part in zip.GetParts())
            {
                using (var reader = new StreamReader(part.GetStream(FileMode.Open, FileAccess.Read)))
                {
                    using (var writer = ZipStreamProvider.GetStream(folder + "\\" + Path.GetFileName(part.Uri.OriginalString)))
                    {
                        var buffer = System.Text.Encoding.UTF8.GetBytes(reader.ReadToEnd());
                        writer.Write(buffer, 0, buffer.Length);
                    }
                }
            }
        }
    }

    public void AddFile(string fileToAdd)
    {
        using (var zip = System.IO.Packaging.Package.Open(ZipFileName, FileMode.OpenOrCreate))
        {
            var destFilename = ".\\" + Path.GetFileName(fileToAdd);
            var uri = PackUriHelper.CreatePartUri(new Uri(destFilename, UriKind.Relative));
            if (zip.PartExists(uri))
            {
                zip.DeletePart(uri);
            }
            var part = zip.CreatePart(uri, "", CompressionOption.Normal);
            using (var fileStream = ZipStreamProvider.GetStream(fileToAdd))
            {
                using (var dest = part.GetStream())
                {
                    CopyStream(fileStream, dest);
                }
            }
        }
    }

    private long CopyStream(Stream inputStream, Stream outputStream)
    {
        var bufferSize = inputStream.Length < BufferSize ? inputStream.Length : BufferSize;
        var buffer = new byte[bufferSize];
        int bytesRead;
        var bytesWritten = 0L;
        while ((bytesRead = inputStream.Read(buffer, 0, buffer.Length)) != 0)
        {
            outputStream.Write(buffer, 0, bytesRead);
            bytesWritten += bufferSize;
        }

        return bytesWritten;
    }
}

/// <summary> /// The commented methods are marked for future /// </summary> public interface IZipper { //void Create(); void ExtractAll(); void ExtractAll(string folder); //void Extract(string fileName); void AddFile(string fileName); //void DeleteFile(string fileName); } public interface IZipStreamProvider { Stream GetStream(string fileName); } public class ZipStreamProvider : IZipStreamProvider { public Stream GetStream(string fileName) { //Create a read/writable file return new FileStream(fileName, FileMode.Create); } } public class Zipper : IZipper { private const long BufferSize = 4096; public string ZipFileName { get; set;} //seam.. to use property injection private IZipStreamProvider ZipStreamProvider { get; set;} public Zipper(string zipFilename) { ZipFileName = zipFilename; //By default, write to file ZipStreamProvider = new ZipStreamProvider(); } public void ExtractAll() { ExtractAll(Environment.CurrentDirectory); } public void ExtractAll(string folder) { using (var zip = System.IO.Packaging.Package.Open(ZipStreamProvider.GetStream(ZipFileName))) { foreach (var part in zip.GetParts()) { using (var reader = new StreamReader(part.GetStream(FileMode.Open, FileAccess.Read))) { using (var writer = ZipStreamProvider.GetStream(folder + "\\" + Path.GetFileName(part.Uri.OriginalString))) { var buffer = System.Text.Encoding.UTF8.GetBytes(reader.ReadToEnd()); writer.Write(buffer, 0, buffer.Length); } } } } } public void AddFile(string fileToAdd) { using (var zip = System.IO.Packaging.Package.Open(ZipFileName, FileMode.OpenOrCreate)) { var destFilename = ".\\" + Path.GetFileName(fileToAdd); var uri = PackUriHelper.CreatePartUri(new Uri(destFilename, UriKind.Relative)); if (zip.PartExists(uri)) { zip.DeletePart(uri); } var part = zip.CreatePart(uri, "", CompressionOption.Normal); using (var fileStream = ZipStreamProvider.GetStream(fileToAdd)) { using (var dest = part.GetStream()) { CopyStream(fileStream, dest); } } } } private long CopyStream(Stream inputStream, Stream outputStream) { var bufferSize = inputStream.Length < BufferSize ? inputStream.Length : BufferSize; var buffer = new byte[bufferSize]; int bytesRead; var bytesWritten = 0L; while ((bytesRead = inputStream.Read(buffer, 0, buffer.Length)) != 0) { outputStream.Write(buffer, 0, bytesRead); bytesWritten += bufferSize; } return bytesWritten; } }

单元测试从Zip添加到Zip / Extracting

3 个答案: