C# 解耦EntityFramework进行单元测试

来源：互联网发布：dns免费域名编辑：程序博客网时间：2024/05/21 08:55

1. 首先EF的Repository需要抽象的行为提到接口中。

例如：

public interface IXXXContext : IDisposable    {        IXXXContext NewInstance();// db sets        DbSet<AAABBB> aaa { get; set; }...// common Database Database { get; }        DbContextConfiguration Configuration { get; }        int SaveChanges();        Task<int> SaveChangesAsync();// store pros...        IStorePro1 StorePro1 { get; }...}

然后就可以使用DataContext和TestDataContext实现这个接口。其中TestDataContext是在UT中使用的，DataContext是自动生成的。

TestDataContext还需要以下几个类进行模拟。

 public class TestDbSet<TEntity> : DbSet<TEntity>, IQueryable, IEnumerable<TEntity>, IDbAsyncEnumerable<TEntity>         where TEntity : class    {        ObservableCollection<TEntity> _data;        IQueryable _query;        public TestDbSet()        {            _data = new ObservableCollection<TEntity>();            _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<TEntity>();        }        public override TDerivedEntity Create<TDerivedEntity>()        {            return Activator.CreateInstance<TDerivedEntity>();        }        public override ObservableCollection<TEntity> Local        {            get { return _data; }        }        Type IQueryable.ElementType        {            get { return _query.ElementType; }        }        Expression IQueryable.Expression        {            get { return _query.Expression; }        }        IQueryProvider IQueryable.Provider        {            get { return new TestDbAsyncQueryProvider<TEntity>(_query.Provider); }        }        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()        {            return _data.GetEnumerator();        }        IEnumerator<TEntity> IEnumerable<TEntity>.GetEnumerator()        {            return _data.GetEnumerator();        }        IDbAsyncEnumerator<TEntity> IDbAsyncEnumerable<TEntity>.GetAsyncEnumerator()        {            return new TestDbAsyncEnumerator<TEntity>(_data.GetEnumerator());        }    }    internal class TestDbAsyncQueryProvider<TEntity> : IDbAsyncQueryProvider    {        private readonly IQueryProvider _inner;        internal TestDbAsyncQueryProvider(IQueryProvider inner)        {            _inner = inner;        }        public IQueryable CreateQuery(Expression expression)        {            return new TestDbAsyncEnumerable<TEntity>(expression);        }        public IQueryable<TElement> CreateQuery<TElement>(Expression expression)        {            return new TestDbAsyncEnumerable<TElement>(expression);        }        public object Execute(Expression expression)        {            return _inner.Execute(expression);        }        public TResult Execute<TResult>(Expression expression)        {            return _inner.Execute<TResult>(expression);        }        public Task<object> ExecuteAsync(Expression expression, CancellationToken cancellationToken)        {            return Task.FromResult(Execute(expression));        }        public Task<TResult> ExecuteAsync<TResult>(Expression expression, CancellationToken cancellationToken)        {            return Task.FromResult(Execute<TResult>(expression));        }    }    internal class TestDbAsyncEnumerable<T> : EnumerableQuery<T>, IDbAsyncEnumerable<T>, IQueryable<T>    {        public TestDbAsyncEnumerable(IEnumerable<T> enumerable)            : base(enumerable)        { }        public TestDbAsyncEnumerable(Expression expression)            : base(expression)        { }        public IDbAsyncEnumerator<T> GetAsyncEnumerator()        {            return new TestDbAsyncEnumerator<T>(this.AsEnumerable().GetEnumerator());        }        IDbAsyncEnumerator IDbAsyncEnumerable.GetAsyncEnumerator()        {            return GetAsyncEnumerator();        }        IQueryProvider IQueryable.Provider        {            get { return new TestDbAsyncQueryProvider<T>(this); }        }    }    internal class TestDbAsyncEnumerator<T> : IDbAsyncEnumerator<T>    {        private readonly IEnumerator<T> _inner;        public TestDbAsyncEnumerator(IEnumerator<T> inner)        {            _inner = inner;        }        public void Dispose()        {            _inner.Dispose();        }        public Task<bool> MoveNextAsync(CancellationToken cancellationToken)        {            return Task.FromResult(_inner.MoveNext());        }        public T Current        {            get { return _inner.Current; }        }        object IDbAsyncEnumerator.Current        {            get { return Current; }        }    }

使用示例：

[TestMethod]        public void TestMethod1()        {            var mockSet = new Mock<DbSet<BLACKLISTED_TICKET>>();            var mockContext = new Mock<TicketDataContextTest>();            mockContext.Setup(m => m.BLACKLISTED_TICKET).Returns(new TestDbSet<BLACKLISTED_TICKET>());            var context = mockContext.Object;            context.BLACKLISTED_TICKET.Add(new BLACKLISTED_TICKET()            {                TicketNumber = "aaa",                CreatedDateTime = DateTime.Now,                Id = 1,                ModifiedDateTime = DateTime.Now,                STATUS = "1"            });            Assert.IsTrue(context.BLACKLISTED_TICKET.First().Id == 1);        }

如果使用了存储过程，需要额外定义存储过程的接口。
例如：

IStorePro {...}StorePro : IStorePro{...}StoreProFake: IStorePro{}

然后IDataContext负责返回存储过程的实例

IDataContext{...IStorePro GetStorePro();...}

1 0