C＃使用Moq从Mock存储库中删除项目

Question

I am trying to do a test delete using the Moq framework in C# and I am testing that the items were removed.

At the bottom, if I set int count to be events.Count, it returns 3. Brilliant!! However if i set it to be EventsMockDatabase.Count(), it returns 5 despite the fact that the mock has been setup to return events.Count.

Can anyone help me explain why?

    [Test]
    public void DeleteDuplicateEventDetailsFromRows()
    {
        var event1 = new EventLogObj() { RecordId = 1, TableKey = "PERSON_CODE=1", Status = "S" };
        var event2 = new EventLogObj() { RecordId = 2, TableKey = "PERSON_CODE=2", Status = "S" };
        var event3 = new EventLogObj() { RecordId = 3, TableKey = "PERSON_CODE=3", Status = "S" };
        var event4 = new EventLogObj() { RecordId = 4, TableKey = "PERSON_CODE=2", Status = "S" };
        var event5 = new EventLogObj() { RecordId = 5, TableKey = "PERSON_CODE=1", Status = "S" };

        var events = new List<EventLogObj>() { event1, event2, event3, event4, event5 };

        var mockEventsRepository = new Mock<IEventRepository>();

        mockEventsRepository.Setup(ev => ev.GetEvents())
            .Returns(events);

        mockEventsRepository.Setup(ev => ev.DeleteEvent(It.IsAny<decimal>()))
            .Callback((decimal RecID) =>
            {
                events.RemoveAll(e => e.RecordId == RecID);
            });

        mockEventsRepository.Setup(ev => ev.Count())              
            .Returns(events.Count);

        IEventRepository EventsMockDatabase = mockEventsRepository.Object;

        var eventLogObjects = new List<EventLogObj>();
        var duplicateEventLogObjects = new List<EventLogObj>();

        foreach (EventLogObj elo in EventsMockDatabase.GetEvents())
        {
            var existing = eventLogObjects.Where(
                e => e.TableKey.Equals(elo.TableKey)
            ).ToList();

            if (existing.Count == 0)
            {
                eventLogObjects.Add(elo);
            }
            else
            {
                duplicateEventLogObjects.Add(elo);
            }
        }

        Assert.AreEqual(2, duplicateEventLogObjects.Count);

        foreach (EventLogObj e in duplicateEventLogObjects)
        {
            // delete by id
            EventsMockDatabase.DeleteEvent(e.RecordId);
        }

        int count = events.Count; // EventsMockDatabase.Count(); // WHY!!!?

        Assert.AreEqual(3, count);
    }

Answer 1

The value that is returned is stored when you Setup the Mock, so in this instance, the size of the initial list (5).

You can get round it by instead setting up the mock with a delegate:

mockEventsRepository.Setup(ev => ev.Count())
    .Returns(() => { return events.Count; });

As an aside, you do know that your current test wouldn't test any production code, it's simply testing if you've set your mock up to simulate a repository?