Question

我想问下面方法 GetMeetingsByInterimIdentifier 什么是良好的单元测试，其中临时标识符是一个字符串 - 例如78th2015。

我们设置使用IMeetingsService接口。我们正在使用MOQ和Microsoft.VisualStudio.TestTools.UnitTesting。

public class MeetingsService : IMeetingsService
{
    private readonly IInterimCommitteeDbContext _db;

    public MeetingsService(IInterimCommitteeDbContext db)
    {
        this._db = db;
    }

    public IQueryable<Meeting> GetMeetingsByInterimIdentifier(string interimIdentifier)
    {
        return
            from m in this._db.Meetings
            join c in this._db.Committees on m.CommitteeId equals c.CommitteeId
            where c.InterimIdentifier == interimIdentifier
            select m;
    }

    public Meeting GetMeeting(int meetingKey)
    {
        return this._db.Meetings.FirstOrDefault(x => x.MeetingId == meetingKey);

    }

}

修改

但我不知道如何设置它。这个结果不是空的，但它对我有什么用呢？

[TestMethod] 
public void GetMeetingsByInterimIdentifier_WithInterimIdentifier_ReturnsMeetingList() 
{ 
    //Arrange 
    var interim = Properties.Settings.Default.DefaultInterimIdentifier; 
    var result = _meetingServiceMock.Setup(x => x.GetMeetingsByInterimIdentifier(interim)); 

    //Act 

    //Assert 
    Assert.IsNotNull(result);
}

Answer 1

使用Mocking，它的用途是什么。使用JMock或Mockito或您喜欢的任何其他库。

Answer 2

创建一个Mock<IInterimCommitteeDbContext>并将其传递给构造函数。在此对象上设置Meetings和Committees属性以返回各种集合。

您应该有不同的测试设置来返回不同的集合。例如，如果Meetings和Committees都为空，即数据库中没有数据，这应该如何表现？如果没有提供InterimIdentifier的对象，它应该如何表现？如果有一个匹配等等怎么样。

Answer 3

我想出了如何使用测试双打来做到这一点。我正在使用Entity Framework 6和代码第一个模型。我创建了一个继承自I-DbContext接口的DbContext。然后我能够创建内存数据以用于我的服务层单元测试。以下是一个例子：

测试数据上下文
测试dbset，
示例单元测试。

此解决方案可从以下msdn文章获得： https://msdn.microsoft.com/en-us/data/dn314429.aspx ...

        public class CommitteeContextTest : ICommitteeDbContext
        {
            public CommitteeContextTest()
            {
                this.Committees = new TestDbSet();
                this.CommitteeMembers = new TestDbSet();
            }
            public Database Database { get; }
            public DbSet Committees { get; set; }
            public DbSet CommitteeMembers { get; set; }
        }
    }

public class TestDbSet : DbSet, IQueryable, IEnumerable, IDbAsyncEnumerable
            where TEntity : class
    {
        ObservableCollection _data;
        IQueryable _query;

        public TestDbSet()
        {
            _data = new ObservableCollection();
            _query = _data.AsQueryable();
        }

        public override TEntity Add(TEntity item)
        {
            _data.Add(item);
            return item;
        }

        public override TEntity Remove(TEntity item)
        {
            _data.Remove(item);
            return item;
        }

        public override TEntity Attach(TEntity item)
        {
            _data.Add(item);
            return item;
        }

        public override TEntity Create()
        {
            return Activator.CreateInstance();
        }
    }

    [TestClass]
    public class CommitteeServiceTest
    {
        private InterimCommitteeContextTest _interimCommitteeContext;
        private ICommitteeService _service;
        private string _interim;

        [TestInitialize]
        public void SetUp()
        {
            _interimCommitteeContext = new InterimCommitteeContextTest();
            _service = new CommitteeService(_interimCommitteeContext);
            _interim = Settings.Default.DefaultInterimIdentifier;
        }

        [TestCleanup]
        public void Teardown()
        {
            _interimCommitteeContext = null;
            _service = null;
        }

        [TestMethod]
        public void GetCommittee_ProvideInterimCommitteeId_ReturnOneCommittee()
        {
            //Arrange
            AddCommittees();

            //Act and Assert
            var result = _service.GetCommittee(_interim, 1);
            Assert.AreEqual(1, result.CommitteeId); //Passes.  IsActive set to true;
            result = _service.GetCommittee(_interim, 0);
            Assert.IsNull(result); //Fails.  No committeeId = 0;
            result = _service.GetCommittee(_interim, 2);
            Assert.IsNull(result); //Fails.  CommitteeId = 2 is not active.
        }

        [TestMethod]
        public void AddCommittees()
        {
            _interimCommitteeContext.Committees.Add(new Committee() { CommitteeId = 1, InterimIdentifier = _interim, IsActive = true, CommitteeTypeId = 1 });
            _interimCommitteeContext.Committees.Add(new Committee() { CommitteeId = 2, InterimIdentifier = _interim, IsActive = false, CommitteeTypeId = 1 });
            _interimCommitteeContext.Committees.Add(new Committee() { CommitteeId = 3, InterimIdentifier = _interim, IsActive = true, CommitteeTypeId = 1 });
        }
    }

如何在不命中数据库的情况下进行单元测试

3 个答案: