Unit testing the app.config file with NUnit

Question

When you guys are unit testing an application that relies on values from an app.config file? How do you test that those values are read in correctly and how your program re

Answer 1

I was facing similar problems with web.config.... I find an interesting solution. You can encapsulate configuration reading function, e.g. something like this:

public class MyClass {

public static Func 
     GetConfigValue = s => ConfigurationManager.AppSettings[s];

//...

}

And then normally use

string connectionString = MyClass.GetConfigValue("myConfigValue");

but in unit test initialize "override" the function like this:

MyClass.GetConfigValue = s =>  s == "myConfigValue" ? "Hi", "string.Empty";

More about it:

http://rogeralsing.com/2009/05/07/the-simplest-form-of-configurable-dependency-injection/