Fake DbContext of Entity Framework 4.1 to Test my repositories

Question

I'm have a Base Repository and all Entities repositories inherits from that.

In my testes i create a Fake DbContext and Fake DbSet to test my repositories, but when implementing some methods in my FakeDbContext I'm not able to implement the IDbContext.Entry method:

public class FakeDbContext : IDbContext
{
    private IDbSet<Usuario> _usuario;
    private IDbSet<Atividade> _atividade;
    private IDbSet<Autor> _autor;
    private IDbSet<CategoriaModulo> _categoriaModulo;
    private IDbSet<CategoriaMateria> _categoriaMateria;
    private IDbSet<Site> _site;
    private IDbSet<Modulo> _modulo;
    private IDbSet<Perfil> _perfil;
    private IDbSet<CategoriaGaleriaImagem> _categoriaGaleriaImagem;

    public IDbSet<Usuario> Usuario { get { return _usuario ?? (_usuario = new FakeDbSet<Usuario>()); } set { } }
    public IDbSet<Atividade> Atividade { get { return _atividade ?? (_atividade = new FakeDbSet<Atividade>()); } set { } }
    public IDbSet<Autor> Autor { get { return _autor ?? (_autor = new FakeDbSet<Autor>()); } set { } }
    public IDbSet<CategoriaModulo> CategoriaModulo { get { return _categoriaModulo ?? (_categoriaModulo = new FakeDbSet<CategoriaModulo>()); } set { } }
    public IDbSet<CategoriaMateria> CategoriaMateria { get { return _categoriaMateria ?? (_categoriaMateria = new FakeDbSet<CategoriaMateria>()); } set { } }
    public IDbSet<Site> Site { get { return _site ?? (_site = new FakeDbSet<Site>()); } set { } }
    public IDbSet<Modulo> Modulo { get { return _modulo ?? (_modulo = new FakeDbSet<Modulo>()); } set { } }
    public IDbSet<Perfil> Perfil { get { return _perfil ?? (_perfil = new FakeDbSet<Perfil>()); } set { } }
    public IDbSet<CategoriaGaleriaImagem> CategoriaGaleriaImagem { get { return _categoriaGaleriaImagem ?? (_categoriaGaleriaImagem = new FakeDbSet<CategoriaGaleriaImagem>()); } set { } }

    public void SaveChanges()
    {
        //do nothing
    }

    public IDbSet<TEntity> Set<TEntity>() where TEntity : class
    {
        foreach (PropertyInfo property in typeof(FakeDbContext).GetProperties())
        {
            if (property.PropertyType == typeof(IDbSet<TEntity>))
                return property.GetValue(this, null) as IDbSet<TEntity>;
        }
        throw new Exception("Type collection not found");
    }

    public System.Data.Entity.Infrastructure.DbEntityEntry Entry<TEntity>(TEntity entity) where TEntity : class
    {
    }
}

The last method I'm not able to implementing, can you guys help me?

I'm using this Entry method to update a Entity in my base repository:

public abstract class BaseRepository<TEntity> : IBaseRepository<TEntity> where TEntity : class
    {
        #region Fields

        protected TEntity EntityType;
        protected IDbSet<TEntity> DbSet;

        #endregion

        #region Properties

        public IDbContext DbContext
        {
            get
            {
                return DbContextFactory.Instance.GetOrCreateContext();
            }
        }

        #endregion

        #region Constructors

        protected BaseRepository()
        {
            this.EntityType = DependencyResolverFactory.Instance.Get<TEntity>();
            this.DbSet = DbContext.Set<TEntity>();
        }

        #endregion

        #region Methods

        public virtual void Add(TEntity entity)
        {
            this.DbSet.Add(entity);
        }

        public virtual void Remove(TEntity entity)
        {
            this.DbSet.Remove(entity);
        }

        public virtual void RemoveById(object id)
        {
            TEntity entity = this.GetById(id);
            this.DbSet.Remove(entity);
        }

        public virtual void Edit(TEntity entity)
        {
            this.DbContext.Entry(entity).State = EntityState.Modified;
        }

        public virtual TEntity GetById(object id)
        {
            return (TEntity)this.DbSet.Find(id);
        }

        public virtual IList<TEntity> GetAll()
        {
            return ((IEnumerable<TEntity>)this.DbSet).ToList();
        }

        #endregion
    }

What is the meaning of testing a repository by fake dbContext. Repository is exacting DbContext directly. Do you have business logic in your repository class? — Jayantha Lal Sirisena, Aug 18 '11 at 12:07
@Ladislav In my repositories i'm not exposing IDbSet or IQueryable to my controller, because that, I'm never using LINQ To Objects in tests and LINQ To Entities in my App, will all LINQ To Objects, and the methods in my repositories will careful use LINQ To Entities. — Acaz Souza, Aug 18 '11 at 12:17

score 6 · Accepted Answer · edited May 23 '17 at 11:51

6

Read this and all linked questions before you continue. Unit testing anything returning EF related classes or working with linq-to-entities is dangerous.

Give up with unit testing your repositories and instead unit test your application logic by faking repositories themselves. If you want to test your repositories create integration tests talking to the real database.

edited May 23 '17 at 11:51

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answered Aug 18 '11 at 12:15

Ladislav Mrnka

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but i'm not exposing IDbSet Or Iqueryable to my controllers. – Acaz Souza Aug 18 '11 at 12:19
Yes you don't but why are you faking the context? – Ladislav Mrnka Aug 18 '11 at 13:04

Fake DbContext of Entity Framework 4.1 to Test my repositories

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