c# Unit Test: Writing to Settings in unit test does not save values in user.config

Question

I am running a c# unit test (VS 2008). Within the test I do write to the settings, which should result in saving the data to the user.config.

Settings.Default.X = "History"; // X is string
Settings.Default.Save();

But this simply does not create the file (I have crosschecked under "C:\Documents and Settings\HW\Local Settings\Application Data").

If I create the same stuff as a Console application, there is no problem persisting the data (same code).

Is there something special I need to consider doing this in a UnitTest?

Answer 1

Unit Test projects are just class libraries. There's no application context and thus you may have problems because the settings object does not know what Company/Application to file the settings file under.

I am unsure, but it may just be creating it in-memory.

Answer 2

I tried it with Visual Studio 2010 on Windows 7 and the Visual Studio Unit Test framework is actually creating a temporary folder for test applications in which I found my user.config file with correct settings. I think it might be the same thing on VS 2008. The path scheme to these folder is of the kind:

Windows Vista/Seven path:

C:\Users\$USER$\AppData\Local\Microsoft_Corporation\TestAppDomain{Number}

Windows XP path:

C:\Documents and Settings\$USER$\Local Settings\Microsoft_Corporation\TestAppDomain{Number}

Good luck.

Answer 3

Thanks for your help, it helped a lot finding the issue. The hint with the path helped me "seeing what is going on" and finding the troublemaker.

BTW, this snippet

 config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.PerUserRoamingAndLocal)
 config.FilePath

is useful finding the storage location.

My problem was that I called Reset() before Reload(). Actually my test case checks whether the objects are stored correctly, so it saves and reloads the settings. I was unaware of the fact, that Reset() "resets and saves on disk" - I was assuming it only resets in memory. I must only call Reload().

Since all test cases have their own directory, the settings have to be created (saved) within the test case.