A Small Unit Testing Gem

Since I started writing unit tests for my code, I had this question in mind. Let's say I have a project that is a class library. I have a class in that library and this class has some internal methods. Like this:

public class MyClass
{
 public void MyPublicMethod
 {
  int k    
  // do something ...    
  int z = MyInternalMethod(k);
  // do something else ...  
 }  
 
 internal int MyInternalMethod(int i)  
 {
  // do something ...  
 }
}

Now I want to write unit tests for these methods. I would create a "UnitTests" project, reference the nunit.framework from it and write something like this:

[TestFixture]
public class UnitTests
{  
 private MyClass myClass;
 
 [SetUp]  
 public void SetupTest  
 {
  myClass = new MyClass();  
 }

 [Test]
 public void TestMyInternalMethod  
 {
  int z = 100;
  int k = myClass.MyInternalMethod(z); //CAN NOT DO THIS!    
  Assert.AreEqual(k, 100000);  
 }

 [TearDown]
 public void TearDown  
 {
  myClass = null;
 }
}

Of course, I can not do this, because of the MyInternalMethod scope. Today the StackOverflow guys pointed me to this little gem which is very helpful.

.Net Gem - How to Unit Test Internal Methods

Here's the short summary:

Go to the project that contains MyClass. Locate the AssemblyInfo.cs file. Add the following line to it:

[assembly: InternalsVisibleTo("UnitTests")]

Done!

by Evgeny. Also posted on my website