模擬方法始終返回null

Question

我有以下代碼：

public int LoadFilesAndSaveInDatabase(string filesPath) 
{ 
    var calls = new ConcurrentStack<GdsCallDto>(); 

    var filesInDirectory = this._directoryProxy.GetFiles(filesPath); 
    if (filesInDirectory.Any()) 
    { 
     Parallel.ForEach(filesInDirectory, file => 
     { 
      var lines = this._fileProxy.ReadAllLines(file, Encoding.Unicode); 
      if (lines.Any()) 
      { 
       // Reads the file and setup a new DTO. 
       var deserializedCall = this._fileManager.DeserializeFileContent(lines, Path.GetFileName(file)); 

       // Insert the DTO in the database. 
       this._gdsCallsData.InsertOrUpdateGdsCall(deserializedCall); 

       // We keep track of the dto to count the number of restored items. 
       calls.Push(deserializedCall); 
      } 
     }); 
    } 
    return calls.Count; 
} 

我具有以下的單元測試：

[TestMethod] 
public void ShouldLoadFilesAndSaveInDatabase() 
{ 
    // Arrange 
    var path = RandomGenerator.GetRandomString(56); 
    var encoding = Encoding.Unicode; 
    var fileNameEnvironment = RandomGenerator.GetRandomString(); 
    var fileNameModule = RandomGenerator.GetRandomString(); 
    var fileNameRecordLocator = RandomGenerator.GetRandomString(6); 
    var fileNameTimestamp = RandomGenerator.GetRandomDateTime().ToString("O").Replace(':', 'o'); 

    // We simulate the presence of 4 files. 
    var files = new List<string> 
    { 
     RandomGenerator.GetRandomString(255), 
     RandomGenerator.GetRandomString(255), 
     RandomGenerator.GetRandomString(255), 
     RandomGenerator.GetRandomString(255) 
    }.ToArray(); 

    var expectedResult = 4; 

    this._directoryProxy.Expect(d => d.GetFiles(path)) 
     .Return(files); 

    this._fileProxy.Expect(f => f.ReadAllLines(path, encoding)) 
     .Return(files).Repeat.Times(files.Length); 

    // Act 
    var result = this._databaseReloadManager.LoadFilesAndSaveInDatabase(path); 

    // Assert 
    Assert.AreEqual(result, expectedResult); 
    this._directoryProxy.AssertWasCalled(d => d.GetFiles(path)); 
    this._fileProxy.AssertWasCalled(f => f.ReadAllLines(path, Encoding.Unicode)); 
} 

的問題是上下面的行：

var lines = this._fileProxy.ReadAllLines(file, Encoding.Unicode); 

即使我設置了期望和返回值，當我運行單元測試時，它總是返回null。

我正在使用Rhino.Mocks，它在其他地方工作得很好，但沒有。

我在這裏看了一些討論，但沒有一個幫助。這可能是由於使用了Parallel.ForEach嗎？有沒有辦法做這樣的模擬？

如果您需要任何其他信息，請讓我知道。

Answer 1

我可以擺脫這個問題，可能是由使用造成的的隨機值。現在我對我的期望調用方法IgnoreArguments（）：

this._fileProxy.Expect(f => f.ReadAllLines(path, encoding)) 
    .Return(files).Repeat.Times(files.Length).IgnoreArguments(); 

它做（即單元測試運行成功）的伎倆，但我不知道這是否是非常優雅。

Answer 2

我不認爲並行化存在問題。看來你的問題與Rhino Mock的代理實例設置有關。

確保您傳入ReadAllLines參數的內容與通過生產代碼運行時調用它們的內容相同。

this._fileProxy.Expect(f => f.ReadAllLines(path, encoding)) 
     .Return(files).Repeat.Times(files.Length); 

例如，如果你設置不同路徑上，當測試執行，您可以在返回NULL看到這條道路diefferent的價值。但是，如果沒有在代碼中看到完整的設置/構造函數，也很難分辨出來。同時檢查隨機生成器，看看每次都使用了什麼。

以下是我整理和爲我工作。 工作意味着我不爲NULL得到：

var lines = this._fileProxy.ReadAllLines(file, Encoding.Unicode); 

---

//some dummy code so I can compile 
public interface IProxyDir 
{ 
    IEnumerable<string> GetFiles(string path); 
} 

public class GdsCallDto 
{ 
} 

public class Proxy : IProxyDir 
{ 
    public IEnumerable<string> GetFiles(string path) 
    { 
     throw new NotImplementedException(); 
    } 
} 

public interface IFileDir 
{ 
    IEnumerable<string> ReadAllLines(string path, Encoding encoding); 
} 

public class FileProxy : IFileDir 
{ 
    public IEnumerable<string> ReadAllLines(string path, Encoding encoding) 
    { 
     throw new NotImplementedException(); 
    } 
} 

public interface IFileMgr 
{ 
    string DeserializeFileContent(IEnumerable<string> lines, string content); 
} 

public class FileMgr : IFileMgr 
{ 
    public string DeserializeFileContent(IEnumerable<string> lines, string content) 
    { 
     throw new NotImplementedException(); 
    } 
} 

//system under test 
public class Sut 
{ 
    private IProxyDir _directoryProxy; 
    private IFileDir _fileProxy; 
    private IFileMgr _fileManager; 

    public Sut(IProxyDir proxyDir, IFileDir fileProxy, IFileMgr mgr) 
    { 
     _fileManager = mgr; 
     _directoryProxy = proxyDir; 
     _fileProxy = fileProxy; 
    } 

    public int LoadFilesAndSaveInDatabase(string filesPath) 
    { 
     var calls = new ConcurrentStack<GdsCallDto>(); 

     var filesInDirectory = this._directoryProxy.GetFiles(filesPath); 
     if (filesInDirectory.Any()) 
     { 
      Parallel.ForEach(filesInDirectory, file => 
      { 
       var lines = this._fileProxy.ReadAllLines("ssss", Encoding.Unicode); 

       if (lines.Any()) 
       { 
        // Reads the file and setup a new DTO. 
        var deserializedCall = this._fileManager.DeserializeFileContent(lines, Path.GetFileName("file")); 

        // Insert the DTO in the database. 
        //this._gdsCallsData.InsertOrUpdateGdsCall(deserializedCall); 

        // We keep track of the dto to count the number of restored items. 
        //calls.Push(deserializedCall); 
       } 
      }); 
     } 

     return 1; 
    } 
} 

---

樣本單位測試

[TestClass] 
public class UnitTest1 
{ 
    private IProxyDir _directoryProxy; 
    private IFileDir _fileProxy; 
    private IFileMgr _fileMgr; 

    private Sut _sut; 

    public UnitTest1() 
    { 
     _directoryProxy = MockRepository.GenerateMock<IProxyDir>(); 
     _fileProxy = MockRepository.GenerateMock<IFileDir>(); 
     _fileMgr = MockRepository.GenerateMock<IFileMgr>(); 
    } 

    [TestMethod] 
    public void ShouldLoadFilesAndSaveInDatabase() 
    { 
     // Arrange 
     var path = RandomGenerator.GetRandomString(56); 
     var encoding = Encoding.Unicode; 
     var fileNameEnvironment = RandomGenerator.GetRandomString(5); 
     var fileNameModule = RandomGenerator.GetRandomString(5); 
     var fileNameRecordLocator = RandomGenerator.GetRandomString(6); 
     var fileNameTimestamp = RandomGenerator.GetRandomDateTime().ToString("O").Replace(':', 'o'); 

     // We simulate the presence of 4 files. 
     var files = new List<string> 
     { 
      RandomGenerator.GetRandomString(255), 
      RandomGenerator.GetRandomString(255), 
      RandomGenerator.GetRandomString(255), 
      RandomGenerator.GetRandomString(255) 
     }.ToArray(); 

     var expectedResult = 4; 

     this._directoryProxy.Expect(d => d.GetFiles(path)) 
      .Return(files); 

     this._fileProxy.Expect(f => f.ReadAllLines(path, encoding)) 
    .Return(files).Repeat.Times(files.Length); 

     _sut = new Sut(_directoryProxy, _fileProxy, _fileMgr); 

     // Act 
     var result = this._sut.LoadFilesAndSaveInDatabase(path); 

     // Assert 
     Assert.AreEqual(result, expectedResult); 
     this._directoryProxy.AssertWasCalled(d => d.GetFiles(path)); 
     this._fileProxy.AssertWasCalled(f => f.ReadAllLines(path, Encoding.Unicode)); 
    } 

} 

internal class RandomGenerator 
{ 
    public static string GetRandomString(int number) 
    { 
     return "ssss"; 
    } 

    public static DateTime GetRandomDateTime() 
    { 
     return new DateTime(); 
    } 
}