NUnit is an open source testing framework for all .NET languages including VB .NET (link)
NUnit will be used to create unit tests for libraries
Download and install NUnit from here
I have created a standard Windows class library project for working with the shared libraries; Avoiding ArcGIS templates
Add nunit.framework to your project references
NUnit test fixtures can be identified by their attributes; Custom dictates that they are stored together in a test folder in the project hierarchy
Helpful article on using NUnit with VB.NET (link)
To run NUnit from the NUnit GUI:
Run nunit-x86.exe (Windows 7) or nunit.exe (Windows XP)
Choose File... Open from the menu
Navigate to the .dll that includes your test cases
To configure NUnit for use by your project. NUnit can be used by the debugger so you can step through test cases:
Tools > External Tools...
Create external with Title: NUnit
Command:
Windows 7 (64bit): C:\Program Files (x86)\NUnit 2.5.7\bin\net-2.0\nunit-x86.exe
Windows XP (32bit): C:\Program Files\NUnit 2.5.7\bin\net-2.0\nunit.exe
Arguments: $(ProjectDir)\$(ProjectFileName)
Initial directory: $(ProjectDir)
Modify your .vbproj.user file to use NUnit for debugging. See attached sample.
When NUnit launches from inside VB Express, it's recommended to verify that NUnit is pointed at the correct code by using the File ... Open dialog