模拟WCF客户端的IQueryable成员

Question

我有一个公开接口的WCF数据服务：

public interface IAccountService
{
    IQueryable<Account> Accounts { get; }
    IQueryable<Contract> Contracts { get; }
}

[DataServiceKey("ID")]
public class Account
{
    public virtual Guid ID { get; set; }
    public virtual string AccountName { get; set; }
    public virtual string Address1 { get; set; }
    public virtual string Address2 { get; set; }
    public virtual string City { get; set; }
    public virtual string State { get; set; }
    public virtual string Zip { get; set; }
    public virtual string Phone { get; set; }
    public virtual string Fax { get; set; }
    public virtual string Status { get; set; }
    public virtual DateTime StartDate { get; set; }
    public virtual IEnumerable<Contract> Contracts { get; set; }
}

[DataServiceKey("ID")]
public class Contract 
{
    public virtual Guid ID { get; set; }
    public virtual string ContractCode { get; set; }
    public virtual string ContractName { get; set; }
    public virtual DateTime StartDate { get; set; }
    public virtual int UnitQty { get; set; }
    public virtual double UnitPrice { get; set; }
}

我想模拟服务客户端进行单元测试。 我想写一个像这样的测试：

[Test]
public void MockContractsFromAccount()
{
    var acctSvc = new Mock<IAccountService>();
    var blah = new Contract[] { new Contract { ContractCode = "BLAH001", ContractName = "blah 1" }, 
        new Contract { ContractCode = "BLAH002", ContractName = "blah 2" } };
    var blee = new Contract[] { new Contract { ContractCode = "BLEE001", ContractName = "blee 1" } };
    var accts = new Account[] { new Account { AccountName = "blah", State = "WY", Contracts = new DataServiceCollection<Contract>(blah) }, 
        new Account { AccountName = "blee", State = "CO", Contracts = new DataServiceCollection<Contract>(blee) } };
    acctSvc.SetupGet(x => x.Accounts).Returns(accts.AsQueryable());

    var result = from x in acctSvc.Object.Accounts
                 where x.State == "CO"
                 select x;
    Assert.That(result, Has.Count.EqualTo(1));
    Assert.That(result.First().Contracts, Has.Count.EqualTo(2));
    Assert.That(result, Is.All.EquivalentTo(blah));
}

但是代码在new DataServiceCollection<Contract>(blah)失败并显示错误消息

SomeTests.MockContractsFromAccount：System.ArgumentException：无法确定DataServiceCollection实例所属的DataServiceContext。 必须在DataServiceCollection构造函数中提供DataServiceContext或将其用于创建DataServiceQuery或QueryOperationResponse对象，该对象是DataServiceCollection中各项的源

这似乎变得非常复杂。 有没有一种方法可以让Visual Studio为Account＆Contract生成接口或获得accts.Contracts返回一个IQueryable<Contract>而不是DataServiceCollection<Contract> ？ 也许还有其他简单的解决方案来模拟此服务？

---

为了清楚起见，svcUtil.exe生成了一个类似于以下内容的Account类：

public class Account 
{
    public Guid ID { get; set; }
    public string AccountName { get; set; }
    public string Address1 { get; set; }
    public string Address2 { get; set; }
    public string City { get; set; }
    public string State { get; set; }
    public string Zip { get; set; }
    public string Phone { get; set; }
    public string Fax { get; set; }
    public string Status { get; set; }
    public DateTime StartDate { get; set; }
    // It descends from IEnumerable<Contract>
    public DataServiceCollection<Contract> Contracts { get; set; }
}

Answer 1

对于那些通过搜索引擎发现此问题的人。

要消除手动创建DataServiceCollection时出现的“ DataServiceContext ...无法确定”异常，请使用TrackingMode参数设置为None的重载构造函数 。

也就是说，

new DataServiceCollection<Contract>(blah, TrackingMode.None)

Answer 2

由于Contracts属性的类型为IEnumerable ，因此您可以创建任何可枚举的集合。

所以，代替

Contracts = new DataServiceCollection<Contract>(blah)

只是使用

Contracts = new [] { blah }

这将确保您在伪造的对象上断开连接。