Mocking Static methods using Rhino.Mocks

Question

Is it possible to mock a static method using Rhino.Mocks? If Rhino does not support this, is there a pattern or something which would let me accomplish the same?

Answer 1

If you can't use TypeMock to intercept the method call, the recommended pattern to use is to create a proxy that forwards to the non-virtual or static methods you are interested in testing, then set the expectation on the proxy. To illustrate, consider the following classes.

class TypeToTest
{
    public void Method() { }
}

interface ITypeToTest
{
    void Method();
}

class TypeToTestProxy : ITypeToTest
{
    TypeToTest m_type = new TypeToTest();

    public void Method() { m_type.Method(); }
}

By creating this proxy, you can now use an ITypeToTest in place of where you were passing or setting a TypeToTest instance, making sure that the default implementation uses the TypeToTestProxy as it forwards to the real implementation. Then, you can create a mock ITypeToTest in your test code and set expectations accordingly.

Note that creating these proxies can be very tedious, error-prone, and time consuming. To address this I maintain a library and set of tools that generate assemblies containing these types for you. Please refer to this page for more information.