Question

我是Moq框架和单元测试的新手，我正在尝试为我的存储库功能创建一个单元测试。

存储库方法

public IQueryable<Campaign> AllIncluding(params Expression<Func<Campaign, object>>[] includeProperties)
{
    IQueryable<Campaign> query = _context.Campaigns;
    foreach (var includeProperty in includeProperties)
    {
        query = query.Include(includeProperty);
    }
    return query;
}

使用Moq设置进行单元测试

//Arrange
var data = new List<Models.Campaign>
{
    new Models.Campaign { Id = 1, Name = "Campaign Past", StartDate = DateTime.Now.AddDays(-10), EndDate = DateTime.Now.AddDays(-5) },
    new Models.Campaign { Id = 2, Name = "Campaign Active", StartDate = DateTime.Now.AddDays(-4), EndDate = DateTime.Now.AddDays(3) },
    new Models.Campaign { Id = 2, Name = "Campaign Future", StartDate = DateTime.Now.AddDays(4), EndDate = DateTime.Now.AddDays(10) }
}.AsQueryable();
var _moqSet = new Mock<DbSet<Models.Campaign>>();
_moqSet.As<IQueryable<Models.Campaign>>().Setup(m => m.Provider).Returns(data.Provider);
_moqSet.As<IQueryable<Models.Campaign>>().Setup(m => m.Expression).Returns(data.Expression);
_moqSet.As<IQueryable<Models.Campaign>>().Setup(m => m.ElementType).Returns(data.ElementType);
_moqSet.As<IQueryable<Models.Campaign>>().Setup(m => m.GetEnumerator()).Returns(data.GetEnumerator());
//_moqSet.As<IQueryable<Models.Campaign>>()
//    .Setup(m => m.Include(It.IsAny<Expression<Func<Models.Campaign, object>>>()))
//    .Returns((Expression<Func<Models.Campaign, object>> predicate) =>
//    {
//        return _moqSet.Object.Include(predicate);
//    });
var _moqContext = new Mock<Context.IPrizeSelectionContext>();
_moqContext.Setup(m => m.Campaigns).Returns(_moqSet.Object);
Func<IQueryable<Models.Campaign>, Expression<Func<Models.Campaign, object>>, IQueryable<Models.Campaign>> includeMethod = (query, expression) =>
{
    return query.Include(expression);
};
//Act
List<Models.Campaign> allResults = null;
using (var sut = new CampaignRepository(_moqContext.Object, includeMethod))
{
    allResults = sut.AllIncluding(o => o.Id, o => o.Name).OrderBy(o => o.Id).ToList();
}
//Assert
Assert.IsNotNull(allResults);
Assert.AreEqual(3, allResults.Count);
Assert.IsNull(allResults[0].StartDate);

我在query.include(includeProperty)尝试模拟include函数后得到一个空数据，但在尝试设置Mock DbSet时遇到Expression references a method that does not belong to the mocked object: m => m.Include<Campaign,Object>(It.IsAny<Expression'1>())异常。经过一番挖掘，我发现Moq有问题或无法模拟扩展方法，请参阅Question Mocking Extionsion Methods with Moq

按照This Blog中的步骤，我尝试执行委托模式

存储库重写

Func<IQueryable<Campaign>, Expression<Func<Campaign, object>>, IQueryable<Campaign>> _includeMethod = null;
...
public CampaignRepository(IPrizeSelectionContext context, Func<IQueryable<Campaign>, Expression<Func<Campaign, object>>, IQueryable<Campaign>> includeMethod)
    : this(context)
{
    _includeMethod = includeMethod;
}
...
public IQueryable<Campaign> AllIncluding(params Expression<Func<Campaign, object>>[] includeProperties)
{
    IQueryable<Campaign> query = _context.Campaigns;
    foreach (var includeProperty in includeProperties)
    {
        if (_includeMethod == null)
            query = query.Include(includeProperty);
        else
            query = _includeMethod(query, includeProperty);
    }
    return query;
}

这是我的单元测试设置

Func<IQueryable<Models.Campaign>, Expression<Func<Models.Campaign, object>>, IQueryable<Models.Campaign>> includeMethod = (query, expression) =>
{
    return query.Include(expression);
};

List<Models.Campaign> allResults = null;
using (var sut = new CampaignRepository(_moqContext.Object, includeMethod))
{
    allResults = sut.AllIncluding(o => o.Id, o => o.Name).OrderBy(o => o.Id).ToList();
}

但是这个模式也以同样的方式结束，IQueryable<Campaign> query = _context.Campaigns;返回Mock类型，但我不能使用扩展方法。

有人能指出我正确的方向来测试我的存储库方法吗？

Answer 1

看起来你正试图在这里测试两件事： 1.包括扩展方法 2. AllIncluding方法

我建议你将Include方法分成不同的静态类，例如：

public static class CollectionExtensions {
public static Include(this IQueryable<Campaign>, Expression<Func<Campaign, object>> includeProperty) {
    // put implementation here
}}

这样，您可以单独测试Include方法。（无论如何，大多数逻辑似乎都在include方法中）

此外，我不认为您可以在_moqSet设置中使用_moqSet.Object，如下所示。这可能是导致moq无法解析表达式的原因。

_moqSet.As<IQueryable<Models.Campaign>>()
.Setup(m => m.Include(It.IsAny<Expression<Func<Models.Campaign, object>>>()))
.Returns((Expression<Func<Models.Campaign, object>> predicate) =>
{
    return _moqSet.Object.Include(predicate);
});

具有IQueryable扩展方法的Moq

存储库方法

使用Moq设置进行单元测试

存储库重写

1 个答案: