Moqing Enity Framework 6 .Include（）using DbSet<> [英] Moqing Enity Framework 6 .Include() using DbSet<>
问题描述
我想给出这个问题的背景。跳过如果你喜欢一段时间以来，我非常关注stackoverflow和其他地方关于测试与EF有关的代码的辩论。一个阵营说，直接对数据库进行测试，因为Linq to Objects& Sql和实现。另一个说嘲笑的测试。
I'd like to give the background to this question. Skip if you like. For quite a while I've paid close attention to the on going debates on stackoverflow and elsewhere regarding testing of code as it relates to EF. One camp says, test directly against a database because of the differences between the Linq to Objects & Sql and implementations. Another says test by mocking.
另一个意见分歧是使用存储库的问题，或者接受DbContext和DbSet已经提供了工作单元和存储库模式。在我使用EF的时候，我尝试了这些营地提供的每一个观点。不管我做了什么，EF证明很难测试。
Another split in opinion is the issue of using repositories, or accepting that DbContext and DbSet already provide a unit of work and repository pattern. In the time that I've been using EF, I've tried about every combination of opinions provided by these camps. Regardless of what I've done, EF proves to be hard to test.
我很高兴找到EF团队 DbSet更可耻。他们还提供了文档关于如何模拟DbSet，包括使用Moq的异步方法。在处理涉及Web Api的最新项目时，我意识到如果我可以模拟EF，我可以跳过写作库，因为写入它们的正常原因是使事情变得可测试。灵感来自阅读几个博客文章，例如 this。 ..
I was excited to find the EF team made DbSet more mockable in EF 6. They also provided documentation on how to mock DbSet, including async methods using Moq. In working on my latest project involving Web Api I realized that if I could mock EF, I could skip writing repositories, as the normal reason for writing them is to make things testable. Inspiration came after reading a few blog posts such as this...
- 背景结束---
--End of background ---
实际问题是以下由EF团队给出的示例代码如何使用Moq DbSet，如果.Include（）用于任何代码，则抛出ArgumentNullException。
The actual problem is that following the example code given by the EF team on how to Moq DbSet, if .Include() is used in any code, an ArgumentNullException is thrown.
其他 SO的相关帖子
这是DbContext的接口：
Here is my interface for DbContext:
public interface ITubingForcesDbContext
{
DbSet<WellEntity> Wells { get; set; }
int SaveChanges();
Task<int> SaveChangesAsync();
Task<int> SaveChangesAsync(CancellationToken cancellationToken);
}
这是我的控制器处理的主要实体
This is the main entity that my controller deals with
public class WellEntity
{
public int Id { get; set; }
public DateTime DateUpdated { get; set; }
public String UpdatedBy { get; set; }
[Required]
public string Name { get; set; }
public string Location { get; set; }
public virtual Company Company { get; set; }
public virtual ICollection<GeometryItem> GeometryItems
{
get { return _geometryItems ?? (_geometryItems = new Collection<GeometryItem>()); }
protected set { _geometryItems = value; }
}
private ICollection<GeometryItem> _geometryItems;
public virtual ICollection<SurveyPoint> SurveyPoints
{
get { return _surveyPoints ?? (_surveyPoints = new Collection<SurveyPoint>()); }
protected set { _surveyPoints = value; }
}
private ICollection<SurveyPoint> _surveyPoints;
public virtual ICollection<TemperaturePoint> TemperaturePoints
{
get { return _temperaturePoints ?? (_temperaturePoints = new Collection<TemperaturePoint>()); }
protected set { _temperaturePoints = value; }
}
private ICollection<TemperaturePoint> _temperaturePoints;
}
这是直接使用EF DbContext的控制器
Here is the controller which directly uses an EF DbContext
[Route("{id}")]
public async Task<IHttpActionResult> Get(int id)
{
var query = await TheContext.Wells.
Include(x => x.GeometryItems).
Include(x => x.SurveyPoints).
Include(x => x.TemperaturePoints).
SingleOrDefaultAsync(x => x.Id == id);
if (query == null)
{
return NotFound();
}
var model = ModelFactory.Create(query);
return Ok(model);
}
最后这是失败的测试...
Finally here is the failing test...
测试设置---
[ClassInitialize]
public static void ClassInitialize(TestContext testContest)
{
var well1 = new WellEntity { Name = "Well 1" };
var well2 = new WellEntity { Name = "Well 2" };
var well3 = new WellEntity { Name = "Well 3" };
var well4 = new WellEntity { Name = "Well 4" };
well1.GeometryItems.Add(new GeometryItem());
well1.TemperaturePoints.Add(new TemperaturePoint());
well1.SurveyPoints.Add(new SurveyPoint());
well2.GeometryItems.Add(new GeometryItem());
well2.TemperaturePoints.Add(new TemperaturePoint());
well2.SurveyPoints.Add(new SurveyPoint());
well3.GeometryItems.Add(new GeometryItem());
well3.TemperaturePoints.Add(new TemperaturePoint());
well3.SurveyPoints.Add(new SurveyPoint());
well4.GeometryItems.Add(new GeometryItem());
well4.TemperaturePoints.Add(new TemperaturePoint());
well4.SurveyPoints.Add(new SurveyPoint());
var wells = new List<WellEntity> { well1, well2, well3, well4 }.AsQueryable();
var mockWells = CreateMockSet(wells);
_mockContext = new Mock<ITubingForcesDbContext>();
_mockContext.Setup(c => c.Wells).Returns(mockWells.Object);
}
private static Mock<DbSet<T>> CreateMockSet<T>(IQueryable<T> data) where T : class
{
var mockSet = new Mock<DbSet<T>>();
mockSet.As<IDbAsyncEnumerable<T>>()
.Setup(m => m.GetAsyncEnumerator())
.Returns(new TestDbAsyncEnumerator<T>(data.GetEnumerator()));
mockSet.As<IQueryable<T>>()
.Setup(m => m.Provider)
.Returns(new TestDbAsyncQueryProvider<T>(data.Provider));
mockSet.As<IQueryable<T>>().Setup(m => m.Expression).Returns(data.Expression);
mockSet.As<IQueryable<T>>().Setup(m =>m.ElementType).Returns(data.ElementType);
mockSet.As<IQueryable<T>>().Setup(m=>m.GetEnumerator()).
Returns(data.GetEnumerator());
return mockSet;
}
[TestMethod]
public async Task Get_ById_ReturnsWellWithAllChildData()
{
// Arrange
var controller = new WellsController(_mockContext.Object);
// Act
var actionResult = await controller.Get(1);
// Assert
var response = actionResult as OkNegotiatedContentResult<WellModel>;
Assert.IsNotNull(response);
Assert.IsNotNull(response.Content.GeometryItems);
Assert.IsNotNull(response.Content.SurveyPoints);
Assert.IsNotNull(response.Content.TemperaturePoints);
}
TestDbAsyncQueryProvider& TestDbAsyncEnumerator直接来自引用的EF团队文档。我已经尝试了几个不同的变体，我如何创建模拟的数据，没有任何运气。
TestDbAsyncQueryProvider & TestDbAsyncEnumerator come directly from the referenced EF team documentation. I've tried several different variations for how I create the data for the mock, haven't had any luck with it.
推荐答案
对于任何有兴趣的人，如何解决 .Include（Foo ） NSubstitute和Entity Framework 6 + 的问题，我以下列方式绕过了我的 Include ：
For anyone who stumbles upon this issue with interest on how to solve the .Include("Foo") problem with NSubstitute and Entity Framework 6+, I was able to bypass my Include calls in the following way:
var data = new List<Foo>()
{
/* Stub data */
}.AsQueryable();
var mockSet = Substitute.For<DbSet<Foo>, IQueryable<Foo>>();
((IQueryable<Post>)mockSet).Provider.Returns(data.Provider);
((IQueryable<Post>)mockSet).Expression.Returns(data.Expression);
((IQueryable<Post>)mockSet).ElementType.Returns(data.ElementType);
((IQueryable<Post>)mockSet).GetEnumerator().Returns(data.GetEnumerator());
// The following line bypasses the Include call.
mockSet.Include(Arg.Any<string>()).Returns(mockSet);
这篇关于Moqing Enity Framework 6 .Include（）using DbSet<>的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
