我怎么能模拟FromSql()方法？

Question

我想知道除了构建一个用于模拟的包装器之外还有什么方法FromSql吗？我知道这个方法是静态的,但是因为它们添加了类似于AddEntityFrameworkInMemoryDatabase实体框架核心的东西,我认为可能还有一个解决方案,我在我的项目中使用EF Core 1.0.1.

我的最终目标是测试此方法:

public List<Models.ClosestLocation> Handle(ClosestLocationsQuery message)
{
    return _context.ClosestLocations.FromSql(
        "EXEC GetClosestLocations {0}, {1}, {2}, {3}",
        message.LocationQuery.Latitude,
        message.LocationQuery.Longitude,
        message.LocationQuery.MaxRecordsToReturn ?? 10,
        message.LocationQuery.Distance ?? 10
    ).ToList();
}

我想确保我的查询是使用我传入其中的相同对象来处理的,基于实体框架6中的这个答案,我可以这样做:

[Fact]
public void HandleInvokesGetClosestLocationsWithCorrectData()
{
    var message = new ClosestLocationsQuery
    {
        LocationQuery =
            new LocationQuery {Distance = 1, Latitude = 1.165, Longitude = 1.546, MaxRecordsToReturn = 1}
    };

    var dbSetMock = new Mock<DbSet<Models.ClosestLocation>>();

    dbSetMock.Setup(m => m.FromSql(It.IsAny<string>(), message))
        .Returns(It.IsAny<IQueryable<Models.ClosestLocation>>());

    var contextMock = new Mock<AllReadyContext>();

    contextMock.Setup(c => c.Set<Models.ClosestLocation>()).Returns(dbSetMock.Object);

    var sut = new ClosestLocationsQueryHandler(contextMock.Object);
    var results = sut.Handle(message);

    contextMock.Verify(x => x.ClosestLocations.FromSql(It.IsAny<string>(), It.Is<ClosestLocationsQuery>(y =>
        y.LocationQuery.Distance == message.LocationQuery.Distance &&
        y.LocationQuery.Latitude == message.LocationQuery.Latitude &&
        y.LocationQuery.Longitude == message.LocationQuery.Longitude &&
        y.LocationQuery.MaxRecordsToReturn == message.LocationQuery.MaxRecordsToReturn)));
}

但是与SqlQuery<T>EF 6 不同,EF FromSql<T>Core中的静态扩展方法,我问这个问题,因为我认为我可能从错误的角度处理这个问题,或者可能有一个比包装器更好的选择,我很感激任何想法就此而言.

Answer 1

我也陷入了同样的情况，菲利普（Philippe）给出的回答有所帮助，但主要方法是投掷System.ArgumentNullException。

通过这个链接，我终于能够编写一些单元测试...

这是我的课程正在测试：

public class HolidayDataAccess : IHolidayDataAccess
{
    private readonly IHolidayDataContext holDataContext;

    public HolidayDataAccess(IHolidayDataContext holDataContext)
    {
        this.holDataContext = holDataContext;
    }

    public async Task<IEnumerable<HolidayDate>> GetHolidayDates(DateTime startDate, DateTime endDate)
    {
        using (this.holDataContext)
        {
            IList<HolidayDate> dates = await holDataContext.Dates.FromSql($"[dba].[usp_GetHolidayDates] @StartDate = {startDate}, @EndDate = {endDate}").AsNoTracking().ToListAsync();
            return dates;
        }
    }
}

这是测试方法：

[TestMethod]
public async Task GetHolidayDates_Should_Only_Return_The_Dates_Within_Given_Range()
{
    // Arrange.

        SpAsyncEnumerableQueryable<HolidayDate> dates = new SpAsyncEnumerableQueryable<HolidayDate>();
        dates.Add(new HolidayDate() { Date = new DateTime(2018, 05, 01) });
        dates.Add(new HolidayDate() { Date = new DateTime(2018, 07, 01) });
        dates.Add(new HolidayDate() { Date = new DateTime(2018, 04, 01) });
        dates.Add(new HolidayDate() { Date = new DateTime(2019, 03, 01) });
        dates.Add(new HolidayDate() { Date = new DateTime(2019, 02, 15) });


    var options = new DbContextOptionsBuilder<HolidayDataContext>()
        .UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString())
        .Options;

    HolidayDataContext context = new HolidayDataContext(options);

    context.Dates = context.Dates.MockFromSql(dates);

    HolidayDataAccess dataAccess = new HolidayDataAccess(context);

    //Act.
    IEnumerable<HolidayDate> resutlDates = await dataAccess.GetHolidayDates(new DateTime(2018, 01, 01), new DateTime(2018, 05, 31));

    // Assert.

    Assert.AreEqual(resutlDates.Any(d => d.Date != new DateTime(2019, 03, 01)), true);
    Assert.AreEqual(resutlDates.Any(d => d.Date != new DateTime(2019, 02, 15)), true);

    // we do not need to call this becuase we are using a using block for the context...
    //context.Database.EnsureDeleted();
}

要使用它，UseInMemoryDatabase您需要Microsoft.EntityFrameworkCore.InMemory从NuGet添加软件包 。帮助器类在这里：

public class SpAsyncEnumerableQueryable<T> : IAsyncEnumerable<T>, IQueryable<T>
{
    private readonly IList<T> listOfSpReocrds;

    public Type ElementType => throw new NotImplementedException();

    public IQueryProvider Provider => new Mock<IQueryProvider>().Object;

    Expression IQueryable.Expression => throw new NotImplementedException();

    public SpAsyncEnumerableQueryable()
    {
        this.listOfSpReocrds = new List<T>();
    }        

    public void Add(T spItem) // this is new method added to allow xxx.Add(new T) style of adding sp records...
    {
        this.listOfSpReocrds.Add(spItem);
    }

    public IEnumerator<T> GetEnumerator()
    {
       return this.listOfSpReocrds.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }

    IAsyncEnumerator<T> IAsyncEnumerable<T>.GetEnumerator()
    {
        return listOfSpReocrds.ToAsyncEnumerable().GetEnumerator();
    }
}

...以及包含FromSql方法的模拟的Db扩展类。

public static class DbSetExtensions
{
    public static DbSet<T> MockFromSql<T>(this DbSet<T> dbSet, SpAsyncEnumerableQueryable<T> spItems) where T : class
    {
        var queryProviderMock = new Mock<IQueryProvider>();
        queryProviderMock.Setup(p => p.CreateQuery<T>(It.IsAny<MethodCallExpression>()))
            .Returns<MethodCallExpression>(x => spItems);

        var dbSetMock = new Mock<DbSet<T>>();
        dbSetMock.As<IQueryable<T>>()
            .SetupGet(q => q.Provider)
            .Returns(() => queryProviderMock.Object);

        dbSetMock.As<IQueryable<T>>()
            .Setup(q => q.Expression)
            .Returns(Expression.Constant(dbSetMock.Object));
        return dbSetMock.Object;
    }
}

希望这可以帮助！

编辑：重构SpAsyncEnumerableQueryable类以具有Add方法。摆脱了采用T数组的参数化构造。实现IQueryProvider Provider => new Mock<IQueryProvider>().Object;以支持.AsNoTracking()。异步调用ToList。