Telerik JustMock
public class Foo
{
[DllImport("Kernel32.dll")]
public static extern int GetCurrentProcessId();
}
...
[TestMethod]
public void FormatCurrentProcessId_OnExecute_ShouldReturnExpected()
{
var expected = 3500;
// Arrange
Mock.Arrange(() => Foo.GetCurrentProcessId()).Returns(expected);
// Act
var myFoo = new Foo();
var actual = myFoo.FormatCurrentProcessId();
// Assert
Assert.AreEqual(string.Format("The current process ID is {0}", expected), actual);
}