努力支持的单元测试冲突

Question

I've inherited some tests with this project. They were working when running against the SQL database, but slowly. I'm trying to switch over to using Effort.
.NET4.5, EF6.2, Effort 1.3.10.

I have two possibly related issues with my unit tests.

It doesn't matter if I run the tests in parallel or not.

1) If I run more than one at a time, I get

Saving or accepting changes failed because more than one entity of type 'Center.Shared.Person' have the same primary key value. Ensure that explicitly set primary key values are unique. Ensure that database-generated primary keys are configured correctly in the database and in the Entity Framework model. Use the Entity Designer for Database First/Model First configuration. Use the 'HasDatabaseGeneratedOption" fluent API or 'DatabaseGeneratedAttribute' for Code First configuration. ---> System.InvalidOperationException: Saving or accepting changes failed because more than one entity of type 'Center.Shared.Person' have the same primary key value. Ensure that explicitly set primary key values are unique. Ensure that database-generated primary keys are configured correctly in the database and in the Entity Framework model. Use the Entity Designer for Database First/Model First configuration. Use the 'HasDatabaseGeneratedOption" fluent API or 'DatabaseGeneratedAttribute' for Code First configuration..

So it appears that the tests are not properly isolated.
Tracing through the code, I can see that CreateTransient is called, but it apparently isn't transient enough.

    public DbConnection CreateConnection(string nameOrConnectionString)
    {
        lock (_lock)
        {
            if (_connection == null)
            {
                _connection = Effort.DbConnectionFactory.CreateTransient();
            }

            return _connection;
        }
    }

In the TestInitialize routine I try to reset the database.

    [TestInitialize]
    public override void Initialize()
    {
        db.Database.Delete();
        db.Database.CreateIfNotExists();
        db.Database.Initialize(true);

This is highly convoluted code, so if we need to post more code, it's a long time before we get to the bottom of the rabbit hole. Probably better to create a PoC.

2) If I run the tests independently, I get a different problem. Again, these passed against SQL but not Effort.

    [TestMethod]
    public void ClientAccessorTests_Find()
    {
        Client result;
        Client client = new Client()
        {
            Complete = false,
            HeadOfHousehold = true,
            PersonID = _person.PersonID
        };

        _accessor.Create(client, _accessor.DefaultConnectionContext);

        result = _accessor.Find(new object[] { client.ClientID }, _accessor.DefaultConnectionContext);

        Assert.IsNotNull(result);  // Fails with Assert.IsNotNull failed. 
    }

Create consists of

    public virtual EntityType Create(EntityType entity, ConnectionContext connectionContext)
    {
        IsContextValid(connectionContext);
        if (entity == null) throw new ArgumentException("", "entity");

        using (var db = CreateDbContext<DbContextType>(connectionContext))
        {
            db.Set<EntityType>().Add(entity);
            db.SaveChanges();
        }

        return entity;
    }

Find consists of

    public virtual EntityType Find(object[] primaryKey, ConnectionContext connectionContext)
    {
        IsContextValid(connectionContext);
        if (primaryKey == null || primaryKey.Length == 0) throw new ArgumentException("", "primaryKey");

        using (var db = CreateDbContext<DbContextType>(connectionContext))
        {
            return db.Set<EntityType>().Find(primaryKey);
        }
    }

I know it is calling CreateDbContext, but tracing into the code, as far as I can tell it appears to be the same database with the same ID.

What is it that should cause the tests to be isolated?
And any ideas on why Find would quit working when using an in-memory database?

Answer 1

I was trying to use the implicit approach, where everything is hooked up via settings in the app.config file.
I started having better luck once I abandoned that approach and created the database connection and set it explicitly.

        System.Data.Common.DbConnection connection = new EffortProviderFactory("").CreateConnection("");
        _accessor = new ClientAccessor();
        _accessor.Connection = connection;
        db = new EntitiesDb(connection);

The base Accessor creates copies of the DB at every turn, which is fine so long as it uses the same DbConnection. So I set that on the accessor and then use it here:

        if (_connection == null) {   // this is the path for the application
            if (connectionContext == null) {
                ret = new T();
            } else {
                ret = (T)Activator.CreateInstance(typeof(T), new object[] { connectionContext });
            }
        } else {  // this is the path for unit tests.
            ret = (T)Activator.CreateInstance(typeof(T), new object[] { _connection });
        }

Finally, I had to add a constructor that took a DbConnection to DbContext and its decendants.

    public EntitiesDb(DbConnection connection) : base(connection) { }

'Find' now works and the tests don't interfere with each other.
Next step is pushing this all down to the base classes.