The Freak Parade

I am currently in the process of writing some custom .NET Configuration classes, such as custom ConfigurationHandler implementations, ConfigurationElementCollection, etc. Configuration classes need to be tested just like any other code, especially if they contain any behavior beyond the simple mapping of an XML property to a class property. It turns out the .NET Configuration API makes this pretty easy:

    [TestFixture]
    public class ConfigurationTestFixture
    {
        [Test]
        public void TestCustomConfig()
        {
            var cfg = GetTestConfiguration();
            Assert.That(cfg, Is.Not.Null);

            var mySection = cfg.GetSection("mySection") as mySection;
            Assert.That(mySection, Is.Not.Null);
            Assert.That(mySection.CustomProp,Is.EqualTo("configuredValue"));
            ...

        }

        private System.Configuration.Configuration GetTestConfiguration()
        {
            var map = new ExeConfigurationFileMap()
                          {
                              ExeConfigFilename =

                              Path.Combine(AppDomain.CurrentDomain.BaseDirectory,

                              "TestApp.config")
                          };

            return ConfigurationManager.OpenMappedExeConfiguration(

                    map, ConfigurationUserLevel.None);
        }

For this to work you’ll need a configuration file with the appropriate XML to test your classes stored at the root of your test project with the Copy To Output Directory property set to Copy If Newer. You could use any path to create your ExeConfigurationFileMap, but for me putting the file at the root seemed the easiest solution.

In looking for a palatable way to add configuration file support to some components I’m writing I looked at a number of articles on the topic, all of which discussed some interesting aspect of the configuration. This article, however, covers it all. It is a little long, but well organized so you can find just the parts you need. If you ever engage in creating a configuration section for your .NET 2.0+ app, this is the reference.

http://www.codeproject.com/KB/dotnet/mysteriesofconfiguration.aspx

That being said, here’s a totally different approach to configuration using the XML Serializer. You would lose some validation capabilities, but you gain virtually unlimited flexibility in your object model and you can write whatever simple configuration model you like without worrying about the configuration namespace classes.

http://www.15seconds.com/issue/040504.htm