C# decouples EntityFramework for unit testing-C#.Net Tutorial-php.cn

1. First of all, EF's Repository needs abstract behavior to be mentioned in the interface.

For example:

public interface IXXXContext : IDisposable
    {
        IXXXContext NewInstance();
// db sets
        DbSet aaa { get; set; }
...
// common 
Database Database { get; }
        DbContextConfiguration Configuration { get; }
        int SaveChanges();


        Task SaveChangesAsync();


	// store pros
...
        IStorePro1 StorePro1 { get; }
	...
}

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Then you can use DataContext and TestDataContext to implement this interface. Among them, TestDataContext is used in UT, and DataContext is automatically generated.

TestDataContext also requires the following classes for simulation.

 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();
        }


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


        public override ObservableCollection 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(_query.Provider); }
        }


        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return _data.GetEnumerator();
        }


        IEnumerator IEnumerable.GetEnumerator()
        {
            return _data.GetEnumerator();
        }


        IDbAsyncEnumerator IDbAsyncEnumerable.GetAsyncEnumerator()
        {
            return new TestDbAsyncEnumerator(_data.GetEnumerator());
        }
    }


    internal class TestDbAsyncQueryProvider : IDbAsyncQueryProvider
    {
        private readonly IQueryProvider _inner;


        internal TestDbAsyncQueryProvider(IQueryProvider inner)
        {
            _inner = inner;
        }


        public IQueryable CreateQuery(Expression expression)
        {
            return new TestDbAsyncEnumerable(expression);
        }


        public IQueryable CreateQuery(Expression expression)
        {
            return new TestDbAsyncEnumerable(expression);
        }


        public object Execute(Expression expression)
        {
            return _inner.Execute(expression);
        }


        public TResult Execute(Expression expression)
        {
            return _inner.Execute(expression);
        }


        public Task