單元測試失敗 - 起訂量不調用方法

Question

給出下面，爲什麼這個單元測試失敗，他說：

預計在模擬調用一次，但爲0次：X => x.Steps.Remove（ It.IsAny（））

配置設置：

x => x.Steps.Remove(It.IsAny<Step>()), Times.Never 
No invocations performed. 

代碼：

public static SubmissionVersion DeleteStep(IRepository repository, SubmissionVersion version, Guid stepId) 
    { 
     Step step = repository.GetById<Step>(stepId); 
     Level level = step.Level; 

     /// Delete child objects 
     Step.DeleteNotifications(repository, step); 

     /// Delete Step 
     version.Steps.Remove(step); 
     repository.Save(version); 
     repository.Delete(step); 

     /// Reorder Levels 
     IList<Level> levels = new List<Level>(); 
     version.Steps.Where(s => s != step).OrderBy(s => s.Level.SortOrder).ForEach(s => 
     { 
      if (!levels.Contains(s.Level)) 
       levels.Add(s.Level); 
     }); 

     Level prevLevel = null; 
     levels.ForEach(lvl => 
     { 
      if (prevLevel != null) 
      { 
       lvl.DependsOnLevel = prevLevel; 
       repository.Save(lvl); 
      } 
      prevLevel = lvl; 
     }); 

     /// Delete Level 
     if (!levels.Contains(level)) 
      repository.Delete(level); 


     int order = 0; 
     List<Step> sorted = version.Steps.OrderBy(c => c.SortOrder).ToList(); 
     sorted.ForEach(c => 
     { /// Update SortOrder for list items 
      c.SortOrder = order++; 
      repository.Save(c); 
     }); 
     return repository.GetById<SubmissionVersion>(version.Id); 
    } 

測試

[Fact] 
public void Should_Call_SubmissionVersionRemoveStepsOnce() 
{ 
    // Arrange 
    var ctx = new TestContext(); 
    ctx 
     .SubmissionVersion 
     .SetupGet(x => x.Steps) 
     .Returns(new List<Step> { ctx.Step }); 

    // Act 
    SubmissionVersion.DeleteStep(
     ctx.Repository.Object, 
     ctx.SubmissionVersion.Object, 
     ctx.Step.Id.Value); 

    // Assert 
    ctx 
     .SubmissionVersion 
     .Verify(x => x.Steps.Remove(It.IsAny<Step>()), Times.Once()); 
} 

的TestContext：

internal class TestContext 
{ 
    // Objects 
    public Note Note { get; private set; } 
    public Section Section { get; private set; } 
    public Step Step { get; private set; } 
    public SubmissionVersionProjectType SubmissionVersionProjectType 
     { get; private set; } 
    public SubmissionVersionStatusHistory SubmissionVersionStatusHistory 
     { get; private set; } 

    // Mocks 
    public Mock<SubmissionVersion> SubmissionVersion { get; private set; } 
    public Mock<IRepository> Repository { get; private set; } 

    public TestContext() 
    { 
     Note = new Note { Id = Guid.NewGuid() }; 
     Section = new Section { Id = Guid.NewGuid(), SortOrder = 0 }; 
     Step = new Step() { Id = Guid.NewGuid() }; 
     SubmissionVersionProjectType 
      = new SubmissionVersionProjectType { Id = Guid.NewGuid() }; 
     SubmissionVersionStatusHistory 
      = new SubmissionVersionStatusHistory { Id = Guid.NewGuid() }; 

     SubmissionVersion = new Mock<SubmissionVersion>(); 
     SubmissionVersion.Setup(x => x.Id).Returns(Guid.NewGuid()); 
     SubmissionVersion.Setup(x => x.Notes.Remove(Note)); 
     SubmissionVersion.Setup(x => x.Sections.Remove(Section)); 
     SubmissionVersion.Setup(x => x.Steps.Remove(It.IsAny<Step>())); 
     SubmissionVersion.Setup(x => x.SubmissionVersionProjectTypes.Remove(SubmissionVersionProjectType)); 
     SubmissionVersion.Setup(x => x.SubmissionVersionStatusHistory.Remove(SubmissionVersionStatusHistory)); 

     Repository = new Mock<IRepository>(); 
     Repository.Setup(x => x.GetById<Note>(Note.Id)).Returns(Note); 
     Repository.Setup(x => x.GetById<Section>(Section.Id)).Returns(Section); 
     Repository.Setup(x => x.GetById<Step>(Step.Id)).Returns(Step); 
     Repository.Setup(x => x.GetById<SubmissionVersionProjectType>(SubmissionVersionProjectType.Id)).Returns(SubmissionVersionProjectType); 
     Repository.Setup(x => x.GetById<SubmissionVersionStatusHistory>(SubmissionVersionStatusHistory.Id)).Returns(SubmissionVersionStatusHistory); 
     Repository.Setup(x => x.GetById<SubmissionVersion>(SubmissionVersion.Object.Id)).Returns(SubmissionVersion.Object); 
    } 
} 

Answer 1

我認爲你缺少一個安裝程序。 Moq會知道.Steps（你已經設置了這個），但它不知道.Remove。

ctx.SubmissionVersion.Setup(x => x.Steps.Remove(It.IsAny<Step>())); 

所以，你的測試將是..

[Fact] 
    public void Should_Call_SubmissionVersionRemoveStepsOnce() 
    { 
     // Arrange 
     var ctx = new TestContext(); 
     ctx 
      .SubmissionVersion 
      .SetupGet(x => x.Steps) 
      .Returns(new List<Step> { ctx.Step }); 
     var submissionVersion = ctx.SubmissionVersion.Object; 

     ctx.SubmissionVersion.Setup(x => x.Steps.Remove(It.IsAny<Step>())); 

     // Act 
     submissionVersion.DeleteStep(
      ctx.Repository.Object, 
      ctx.SubmissionVersion.Object, 
      ctx.Step.Id.Value); 

     // Assert 
     ctx 
      .SubmissionVersion 
      .Verify(x => x.Steps.Remove(It.IsAny<Step>()), Times.Once()); 
    } 

現在你刪除Steps.Remove或致電不是從你的SUT（submissionVersion）一次，測試將失敗。只有在測試通過後纔會打電話。