gistfile1.cs

public interface IDomainEntity
    {
        object Id { get; set; }
    }

public interface IRepository<T> : IDisposable where T : IDomainEntity
    {
        IQueryable<T> GetAll();
        IQueryable<T> Query(string sql, params object[] args);
        IQueryable<T> PagedQuery(long pageNumber, long pageSize, string sql, params object[] args);
        T Get(object key);
        void Add(T entity);
        void Delete(T entity);
        void Update(T entity, object key);
        void Save();
    }

public class MockRepository<T> : IRepository<T> where T : IDomainEntity
    {
        private Collection<T> items { get; set; }

        public MockRepository()
        {
            items = new Collection<T>();
        }

        public IQueryable<T> GetAll()
        {
            return this.items.AsQueryable();
        }

        public IQueryable<T> Query(string sql, params object[] args)
        {
            return items.AsQueryable().Where(sql, args);
        }

        public IQueryable<T> PagedQuery(long pageNumber, long pageSize, string sql, params object[] args)
        {
            int skip = ((pageNumber - 1) * pageSize) > int.MaxValue ? int.MaxValue : (int)((pageNumber - 1) * pageSize);
            int take = pageSize > int.MaxValue ? int.MaxValue : (int)pageSize;
            return this.Query(sql, args).Skip(skip).Take(take);
        }

        public void Add(T entity)
        {
            items.Add(entity);
        }

        public void Delete(T entity)
        {
            items.Remove(entity);
        }

        public void Update(T entity, object key)
        {
            items.Remove(items.Where(k => k.Id == key).FirstOrDefault());
        }

        public T Get(object key)
        {
            return items.Where(k => k.Id == key).FirstOrDefault();
        }

        public void Save() { }

        public void Dispose()
        {
            if(this.items != null)
                this.items.Clear();
        }
    }