起订量返回使用Where（）

Question

我试图建立一个模拟从集合返回数据：

private IList<DutyCategory> dutyCategories; 
    private Mock<IDutyCategoryService> mockService; 

    [TestInitialize()] 
    public void UnitTestSetup() 
    { 
     dutyCategories = new List<DutyCategory>() 
     { 
      new DutyCategory(){Description = "Description",ID = 1,IsActive = true,Name = "Test 1",OrganizationID = 1} 
     }; 
     mockService = new Mock<IDutyCategoryService>(); 
     mockService.Setup(a => a.GetDutyCategories()).ReturnsAsync(dutyCategories); 
     mockService.Setup(a => a.GetDutyCategoriesByOrganization(It.IsAny<int>())) 
      .ReturnsAsync((int id) => dutyCategories.Where(n=>n.OrganizationID == id)); 
    } 

，在UnitTestSetup最后一行就是问题所在。我得到以下错误：

Cannot convert lambda expression to type 'System.Collections.Generic.IEnumerable' because it is not a delegate type

我该如何嘲笑GetDutyCategoriesByOrganization，以便它返回列表dutyCategories的子集？

Answer 1

这似乎工作：

.Returns<int>(i => Task.FromResult(dutyCategories.Where(n => n.OrganizationID == i)));