使用FileStream模拟使用

Question

我一直试图模拟使用文件流,但无法完成这个,我不知道该怎么做,我正在使用犀牛模拟.

private Connection LoadConnectionDetailsFromDisk(string bodyFile)
{     
   //logic before
   using (FileStream fs = File.Open(bodyFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
   {
     return this.serverConfiguration.LoadConfiguration(fs, flowProcess);
   }
    //more logic
}

谁能告诉我如何模拟使用(FileStream ....)所以我能够访问代码的这个分支？

Answer 1

你必须File.Open()通过接口方法进行抽象,然后你就可以模拟对它的调用.

所以

1)创建一个界面:

public interface IFileDataSource
{
   FileStream Open(string path,
                   FileMode mode,
                   FileAccess access,
                   FileShare share);
}

2)变更LoadConnectionDetailsFromDisk()如下:

private Connection LoadConnectionDetailsFromDisk(string path, IFileDataSource fileSource)
{     
   using (FileStream fs = fileSource.Open(bodyFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
   {
      return this.serverConfiguration.LoadConfiguration(fs, flowProcess);
   }

   //more logic
}

3)在测试中模拟接口并注入模拟

// create a mock instance
var sourceMock = MockRepository.GenerateMock<IFileDataSource>();

// setup expectation
sourceMock.Expect(m => m.Open("path", FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
         .CallBack(
 delegate (string path, FileMode mode, FileAccess access, FileShare share)
 {
      // handle a call

     return true;
 }).Repeat.Any();

// TODO: depends on how you are triggering LoadConnectionDetailsFromDisk method call
// inject a mock

考虑到LoadConnectionDetailsFromDisk()你不能直接将mock注入这个方法调用froma test,所以请说明如何调用这个方法.