Kanban eBook

I blogged about Kanbanery a while back but failed to notice their really concise ebook on Kanban. Definitely worth a quick read if you are thinking of doing Kanban and need a quick introduction.

Kanban eBook

Integration testing of stored procedures using c# and NUnit

In a recent post I described setting up a database test framework to test an MS SQL database. The purpose of creating this framework was to ensure that in stored procedure heavy applications, we could still get a high level of automated test coverage (which is incredibly important for any application that uses any kind of continuous delivery process). That framework didn’t include an easy way to iterate through a result set and was limited to testing just the number results returned. (See this post for the original framework. Let me know if you need the source and ill get it zipped up).

I have now extended the framework to include the capability of executing a stored procedure with parameters, and then iterate through a result set by mapping the output to a data model.

Model the data

First set up a model of your data

public class CustomerBasicAccountModel

{

        public string CustomerID { get; set; }

        public string CustomerSortCode { get; set; }

        public string CustomerAccountNumber { get; set; }

        public string CustomerAffiliation { get; set; }

}

To facilitate reading of the data returned from a stored procedure I extend the datareader class to consume the reader using linq. This will allow me to easily manage the data once it is returned from the database.

using System;

using System.Collections.Generic;

using System.Data.SqlClient;

namespace  Database.Integration.DAL

{

    static class Extensions

    {

        public static IEnumerable<T> Select<T>(this SqlDataReader reader,

                                       Func<SqlDataReader, T> projection)

        {

            while (reader.Read())

            {

                yield return projection(reader);

            }

        }

    }

}

Finally in the test we can do something like this

[Test]

public void TestSortCode()

 {

            using (var session = _dbFactory.Create())

            {

                var z = session.GetTransaction().Connection.CreateCommand();

                z.CommandTimeout = 0;

                z.CommandType = CommandType.StoredProcedure;

                    var query = session.CreateQuery(

                    @"[GetCustomerBasicAccount]");

                query.AddParameter("@customerid", 3, DbType.Int32);

               

                var dataReader = query.GetAllResults();

                while (dataReader.IsClosed==false | dataReader.Read())

                {

                    using (dataReader)

                    {

                     customerBasicAccount = dataReader.Select(r => new                    CustomerBasicAccountModel

                                         {

                                         customerSortCode =

                                         r["CustomerSortCode"] is DBNull

                                         ? null

                                         : r["CustomerSortCode"]

                                         }).ToList();

                    }

                    Assert.AreEqual(customerBasicAccount[0].customerSortCode, 278222);

                }

            }

        }

Although this is a somewhat crude way to run integration tests on a database, it really does the trick. My original idea was that developers would simply use existing data mapping within a project and write the integration tests using that, but it has always been difficult to get them to commit to doing this. This framework is generic and can be used in any .net project with ease.

Unit testing databases using c# and Nunit

I have been looking at ways to regression test the data access layer of a .Net application that has a heavy reliance on stored procedures. There are tools that can help do this, and I did consider both dbfit and ndbunit, but neither of them could satisfy my criteria.

Criteria

• Ease of use – No time to train developers or testers on how to use a new test framework
• Ability to use straight SQL statements
• The tool or mechanism must integrate easily into this and other projects.  I also need to provide unit testing for a data warehouse project, so something that I could use on both would be perfect
• The generated tests must be easy to put under version control. Being able to tightly couple tests with a specific version or schema is very important, but more about that another time.

The .net application I'm trying to test already has a data access layer that could be used to create these tests, but the implementation of this particular layer is complicated and would require the test engineers working on the project to have a high level of .net code understanding.

Solution

The solution I came up with creates a very simple data access layer using System.Data.SqlClient  and Nunit (download NUnit here). The only complexity that the tester needs to think about is the way they construct the sql and how they write assertions.

Using standard nunit test fixtures, in the test set up I connect to a database, and then in the tests I execute queries and stored procedures, using simple asserts to validate the results.

Here is how its done.

Created a standard class library project that references:

Nunit
nunit.framework

Microsoft
system.data

I'm using a factory pattern with interfaces that allow easy creation of a database session management class which can be used throughout multiple test fixtures. The session manager has methods that create connections to a database defined in a factory, query the database, and execute stored procedures.

The test fixture:

using System;
using NUnit.Framework;
using Codedetective.Database;


namespace Codedetective.Tests
{
    [TestFixture]
    public class DbChecks
    {
        readonly IDatabaseSessionFactory _dbFactory;


        public DbChecks()
        {
            _dbFactory = DatabaseSessionFactory.Create
                (@"Database=CodeDectiveExamples;Data Source=local\test;
                    User=*******;Password=******);
        }


        [Test, Description(“Identify whether TestSet 501 is created and active”)]
        public void DbTest01()
        {
            using (var session = _dbFactory.Create())
            {
                var query = session.CreateQuery(
                    @"select count(*) from testset
                      where testSetId = 501 and Active = '1'");
                var result = query.GetSingleResult<int>();
                Console.WriteLine("test 1 " + ((result == 1) ? "passed" : "failed"));
                Assert.AreEqual(result, 1);
            }
        }

The database session manager:

namespace Codedetective.Database
{
    public class DatabaseSession : IDatabaseSession
    {
        public string ConnectionString { get; set; }
        private SqlConnection _connection;
        private SqlTransaction _transaction;


        public DatabaseSession(string connectionString)
        {
            ConnectionString = connectionString;
        }


        public SqlConnection GetConnection()
        {
            if (_connection == null)
            {
                InitializeConnection();
            }


            return _connection;
        }


        public SqlTransaction GetTransaction()
        {
            if (_transaction == null)
            {
                InitializeConnection();
            }


            return _transaction;
        }


        private void InitializeConnection()
        {
            _connection = new SqlConnection(ConnectionString);
            _connection.Open();


            _transaction = _connection.BeginTransaction();
        }


        public void Dispose()
        {
            if (_transaction != null)
                _transaction.Dispose();


            if (_connection != null)
                _connection.Dispose();
        }


        public IDatabaseQuery CreateQuery(string query)
        {
            var command = GetConnection().CreateCommand();


            command.CommandText = query;
            command.Transaction = _transaction;


            return new DatabaseQuery(command);
        }


        public IDatabaseNoQuery CreateNoQuery(string insertstring)
        {
            var command = GetConnection().CreateCommand();
            command.CommandText = insertstring;
            command.Transaction = _transaction;


            return new DatabaseNoQuery(command);
        }


        public void Commit()
        {
            _transaction.Commit();
        }


        public void Rollback()
        {
            _transaction.Rollback();
        }
    }
}

The interface of the DatabaseSession class:

using System;
using System.Data.SqlClient;


namespace Codedetective.Database
{
    public interface IDatabaseSession : IDisposable
    {
        IDatabaseQuery CreateQuery(string query);
        IDatabaseNoQuery CreateNoQuery(string insertstring);


        SqlConnection GetConnection();
        SqlTransaction GetTransaction();


        void Commit();
        void Rollback();
    }
}

The factory that we use to create the database session manager

namespace Codedetective.Database
{
    public class DatabaseSessionFactory : IDatabaseSessionFactory
    {
        public string ConnectionString { get; set; }


        public IDatabaseSession Create()
        {
            return new DatabaseSession(ConnectionString);
        }


        public static IDatabaseSessionFactory Create(string connectionString)
        {
            var sessionFactory = new DatabaseSessionFactory
            {
                ConnectionString = connectionString
            };


            return sessionFactory;
        }
    }
}

The interface for DatabaseSessionFactory:

namespace Codedetective.Database
{
    public interface IDatabaseSessionFactory
    {
        IDatabaseSession Create();
    }
}

Finally we create the methods that will be used to execute queries and stored procedures

using System;
using System.Collections.Generic;
using System.Data.SqlClient;


namespace Codedetective.Database
{
    public class DatabaseQuery : IDatabaseQuery
    {
        SqlCommand Command { get; set; }


        public DatabaseQuery(SqlCommand command)
        {
            Command = command;
        }


        public void AddParameter(string name, object value, System.Data.DbType dbType)
        {
            var parameter = Command.Parameters.AddWithValue(name, value);
            parameter.DbType = dbType;
        }


        public TResult GetSingleResult<TResult>()
        {
            return (TResult)Convert.ChangeType(Command.ExecuteScalar(), typeof(TResult));
        }


        public IEnumerable<TResult> GetResults<TResult>()
        {
            Type resultType = typeof(TResult);
            IList<TResult> result = new List<TResult>();


            if (resultType.FullName.StartsWith("System."))
            {
                using (var reader = Command.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        var value = reader.GetValue(0);
                        result.Add((TResult)(value != DBNull.Value ? value : null));
                    }
                }
            }
            else
            {
                var properties = typeof(TResult).GetProperties();


                using (var reader = Command.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        var entity = Activator.CreateInstance<TResult>();


                        foreach (var property in properties)
                        {
                            var value = reader[property.Name];
                            property.SetValue(entity, value != DBNull.Value ? value : null, null);
                        }
                        result.Add(entity);
                    }
                }
            }
            return result;
        }
    }
}

The interface for DatabaseQuery is IDatabaseQuery:

using System.Collections.Generic;
using System.Data;


namespace Codedetective.Database
{
    public interface IDatabaseQuery
    {
        void AddParameter(string name, object value, DbType dbType);


        TResult GetSingleResult<TResult>();
        IEnumerable<TResult> GetResults<TResult>();
    }
}

Now for stored procedures execution, we create a class called DatabaseNoQuery

using System.Data.SqlClient;


namespace Codedetective.Database
{
    public class DatabaseNoQuery : IDatabaseNoQuery
    {
        SqlCommand Command { get; set; }


        public DatabaseNoQuery(SqlCommand command)
        {
            Command = command;
        }


        public void AddParameter(string name, object value, System.Data.DbType dbType)
        {
            var parameter = Command.Parameters.AddWithValue(name, value);
            parameter.DbType = dbType;
        }


        public int ExecuteInsert()
        {
            int rows = Command.ExecuteNonQuery();
            return rows;
        }
    }
}


The interface for DatabaseNoQuery is IDatabaseNoQuery

namespace Codedetective.Database
{
    public interface IDatabaseNoQuery
    {
        int ExecuteInsert();
        void AddParameter(string name, object value, System.Data.DbType dbType);
    }
}

This is a long way from being a tool such as DbFit which opens up automation to even non programmers, but it serves a purpose, and does it well. The entire team can now write these tests which can be run alongside the rest of the project tests.

Solving system Integration configuration problems

I am doing a lot of semi-automated application configuration management at the moment. I'm working on a system that has about 30 to 40 interdependent services, web sites, and applications. With an expanding team, splitting into several teams from one large team, the organisation needs to be able to easily replicate development, test and UAT environments on a team by team basis. We could use virtualisation to replicate a master environment set consisting of database and code servers, giving each team a clone of this, but we would still need to invest a lot of time configuring end points and database connection strings.

Whilst trying to solve this problem I came across a really interesting tool that almost does what I think is required.

Octopus Deploy

Octopus is an automated deployment tool developed by Paul Stovell for .NET that uses Nuget and configuration conventions to push out applications in a very effective way to multiple environments. 

Check out the feature set here.

Octopus has a central server that pushes packages out to tentacles that sit on servers. The tentacles look after the deployment server side meaning permission issues are never a problem.

One of the great things is the way you can store all your application or web configuration variables and easily assign different configuration sets to different environments. This is one of the key features for me.

This is pretty much what I want, except that it is heavily dependent on using Nuget packages. This is not a massive issue and if my proof of concept goes well, I will try and convince the teams that they need to be generating Nuget packages as part of their build process. It does actually link into tools like teamcity very well to do this so it may even be possible to leverage the generation of artefacts and use them as the packages.

Related Tools:

Chef - System integration configuration

Puppet - IT automation software

ThoughtWorks Tech Radar - March 2012

The latest ThoughtWorks Technology Radar is now out!

http://www.thoughtworks.com/radar

"The ThoughtWorks Technology Advisory Board is a group of senior technology leaders within ThoughtWorks. They produce the ThoughtWorks Technology Radar to help decision makers understand emerging technologies and trends that affect the market today. This group meets regularly to discuss the global technology strategy for ThoughtWorks and the technology trends that significantly impact our industry." ThoughtWorks 2012

Check out the archives for some interesting trends over the past few years. Interesting reading.

scrum.org

Whilst looking for a course that would allow me to get some professional recognition for my scrum knowledge, I came across scrum.org. Scrum.org was founded c.2010 by Ken Schwaber, one of the original founders of the scum alliance. He resigned from the alliance in 2009 to pursue his belief that a transformation was required in the way the principles and fundamentals of scrum were delivered to users of scrum. There is more about that here.

Scrum.org offers a number of different training and assessment packages with several that are tailored towards developers, focusing on the core engineering practices that developers and scrum masters really need to understand to be successful in a scrum environment.

For more information on scrum visit:

http://www.scrum.org

http://www.scrumalliance.org/

http://kenschwaber.wordpress.com/ 

and have a read of Henrik Kniberg’s Scrum and xp from the trenches:

http://www.infoq.com/minibooks/scrum-xp-from-the-trenches

blazemeter - JMeter cloud testing

I've been using Apache's performance test tool JMeter for many years now, but struggle to find enough time and resource to create a decent distributed network of JMeter engines that can simulate large and realistic load. Today I stumbled upon http://blazemeter.com/ which allows just that. Its a cloud based performance test service that gives you access to multiple instances of JMeter that are geographically distributed on a variety of different server types.

To use blazemeter you either upload your own JMeter scripts or give blazemeter a url and let it write the script for you, you then create your scenarios before finally executing your test. Blazemeter has many great features, including some detailed analysis and test management capabilities that make this a compelling option when it comes to investing in performance testing.

Blazemeter operates a similar business model to browsermob.com (now Neustar Web Performance), where you pay for the number of test engines, different server types, on demand usage, etc.

There is a comprehensive free trial available that will allow you to experiment with features and tests for a couple of weeks.

For more information on JMeter visit http://jmeter.apache.org/.