Is there a way to get a System.Configuration.Configuration instance based on arbitrary xml?

Question

I'm trying to unit test a custom ConfigurationSection I've written, and I'd like to load some arbitrary configuration XML into a System.Configuration.Configuration for each test (rather than put the test configuration xml in the Tests.dll.config file. That is, I'd like to do something like this:

Configuration testConfig = new Configuration("<?xml version=\"1.0\"?><configuration>...</configuration>");
MyCustomConfigSection section = testConfig.GetSection("mycustomconfigsection");
Assert.That(section != null);

However, it looks like ConfigurationManager will only give you Configuration instances that are associated with an EXE file or a machine config. Is there a way to load arbitrary XML into a Configuration instance?

Answer 1

There is actually a way I've discovered....

You need to define a new class inheriting from your original configuration section as follows:

public class MyXmlCustomConfigSection : MyCustomConfigSection
{
    public MyXmlCustomConfigSection (string configXml)
    {
        XmlTextReader reader = new XmlTextReader(new StringReader(configXml));
        DeserializeSection(reader);
    }
}

You can then instantiate your ConfigurationSection object as follows:

string configXml = "<?xml version=\"1.0\"?><configuration>...</configuration>";
MyCustomConfigSection config = new MyXmlCustomConfigSection(configXml);

Hope it helps someone :-)

Answer 2

I think what you're looking for is ConfigurationManager.OpenMappedExeConfiguration

It allows you to open a configuration file that you specify with a file path (wrapped inside a ExeConfigurationFileMap)

If what the other poster said is true, and you don't wish to create a whole new XML file for testing, then I'd recommend you put your Configuration edits in the Test method itself, then run your tests against the freshly changed configuration data.

Answer 3

Looking at the members of the class, I'd say the answer is probably no*. I'm not sure why you'd want to do this anyway, rather than create your own XML configuration file.

*That's no, excluding messy reflection hacks