How to mock SqlParameterCollection using Moq

Question

I am trying to mock database operations. I have problem in mocking SqlParameterCollection . I tried to create virtual method that will return DbParameterCollection but then i am loosing all the functionality that SqlParameterCollection gives like AddWithValue etc. Is there a way i can mock SqlParameterCollection ? Is there any other approach to unit test DAL? I am using Moq.

Code goes like this:

in DAL:

protected virtual IDbConnection GetConnection(string connectionString)
{
    return new SqlConnection(connectionString);
}

protected virtual IDbCommand GetCommand(IDbConnection cn)
{
    return cn.CreateCommand();
}

protected virtual IDbTransaction GetTransaction(IDbConnection cn)
{
    return cn.BeginTransaction(IsolationLevel.Serializable);
}

Public Bool InsertInDatabase(DataTable dt)
{
   using (IDbConnection cn = GetConnection(cnstr))
      {
         cn.Open();

            using (IDbTransaction tran = GetTransaction(cn))
            {
                IDbCommand cmd = GetCommand(cn);
                cmd.Transaction = tran;
                cmd.Connection = cn;
                cmd.CommandType = CommandType.StoredProcedure;

                cmd.CommandText = "sp_InsertInDatabase";
                SqlParameterCollection cmdParams = cmd.Parameters as SqlParameterCollection;
                cmdParams.AddWithValue("@param1", dt);
                cmd.ExecuteNonQuery();
           }
     }
}

In Unit test project:

    protected override IDbConnection GetConnection(string connectionString)
    {
        return Mock.Of<IDbConnection>();
    }

    protected override IDbCommand GetCommand(IDbConnection cn)
    {
        return Mock.Of<IDbCommand>();
    }

    protected override IDbTransaction GetTransaction(IDbConnection cn)
    {
        return Mock.Of<IDbTransaction>();
    }

    public void TestInsertInDatabase()
    {
        base.InsertInDatabase(new DataTable());
    }

--Solution--

Created an extension method to add parameter with value. Thank you Marc Gravell for pointing me to that direction.

    public static IDbDataParameter AddParameterWithValue(this IDbCommand cmd, string paramName, object paramValue)
    {

        var dbParam = cmd.CreateParameter();
        if (dbParam != null)
        {
            dbParam.ParameterName = paramName;
            dbParam.Value = paramValue;
        }
        return dbParam;

    }

Answer 1

Personally, I approach this problem by writing an AddParameterWithValue extension method to DbCommand (or IDbCommand ). It has to be on the command so that you have access to CreateParameter , and then call .Parameters.Add .

This allows easy usage against any ADO.NET stack, including abstractions like logging decorators.

Answer 2

@Asdfg HI I have basically mocked the parameter collection as below

 string connectionString = "connectionstring";
        var sqlConnection = new SqlConnection(connectionString);
        var command = sqlConnection.CreateCommand();
        //****************Setup Mock************************//
        Castle.DynamicProxy.Generators.AttributesToAvoidReplicating.Add(typeof(System.Data.SqlClient.SqlClientPermissionAttribute));
        var mockDataReader1 = new Mock<IDataReader>();
        command.Parameters.Add(new SqlParameter("@po_tint_Result", 1));
        //setup read return value
        Queue<bool> responseQueue = new Queue<bool>();
        responseQueue.Enqueue(true);
        responseQueue.Enqueue(false);
        mockDataReader1.Setup(a => a.Read()).Returns(() => responseQueue.Dequeue());
        var mockDb = new Mock<SqlDatabase>(connectionString);
        mockDb.Setup(a => a.GetStoredProcCommand("SPNAME")).Returns(command);
        mockDb.Setup(a => a.ExecuteNonQuery(command));
        obj1.DbConn = mockDb.Object;
        //*************************************************//

Hope this helps

Answer 3

Hi i found the solution.

I had to implement a Moq for the IDataParameterCollection interface and had to send it to the instance of IDbCommand.

With that my IDbCommand.Parameters object became different from null.

    public static IDbConnection IDbConnectionMock(int valReturn)
    {
        var dataParameterCollection = new Mock<IDataParameterCollection>();

        var command = new Mock<IDbCommand>();
        command.Setup(x => x.Parameters).Returns(dataParameterCollection.Object);
        command.Setup(x => x.ExecuteNonQuery()).Returns(valReturn);

        var connection = DbConnectionMock_Success(command.Object);

        return connection;
    }