Unit-Testing an Action with NUnit

Question

I'd like to unit-test the following function with NUnit and Rhino Mocks. The function uses the given parameters to create a RestSharp.RestRequest and give the request to the dataAccessApi:

public void CopyToUserSession(string uri, string sourcePath)
{
    RestRequest request = new RestRequest(uri, Method.POST);
    request.AddParameter("source-path", sourcePath);

    dataAccessApi.Request<object>(request, restExecution.Get);
}

This is the testing Class:

public void CopyToUserSession_ValidUriAndParameter_CallDataAccessRequest()
{
    // Arrange
    var dataAccessApi = MockRepository.GenerateMock<IDataAccessApi>();
    var restExecution = MockRepository.GenerateMock<IRestExecution>();
    var sinkNodeResource = new SinkNodeResource(dataAccessApi, restExecution);

    string uri = "http://SomeUri.com";
    string sourcePath = "Some Source Path";

    RestRequest request = new RestRequest(uri, Method.POST);
    request.AddParameter("source-path", sourcePath);

    // Act
    sinkNodeResource.CopyToUserSession(uri, sourcePath);

    // Assert
    dataAccessApi.AssertWasCalled(x => x.Request<object>(request, restExecution.Get));
}

The IDataAccessApi...:

public interface IDataAccessApi
{
    void Request<T>(RestRequest request, Action<T> callbackAction) where T : new();
} 

... and the IRestExecution:

public interface IRestExecution
{
    void Get(object o);

    void Put(object o);

    void Post(object o);

    void Delete(object o);
}

The test worked with easier functions to call (like x.Test("Some String")) but does not with the Action new RestExecution().Get - how do i unit-test such calls?

Thank you in advance for your help!

Edit: Changed the Code regarding @rich.okelly comment.

Edit: Added the code for the interfaces

Answer 1

Try the following:

// arrange
var dataAccessApi = MockRepository.GenerateMock<IDataAccessApi>();
var restExecution = MockRepository.GenerateMock<IRestExecution>();
var sinkNodeResource = new SinkNodeResource(dataAccessApi, restExecution);
string uri = "http://SomeUri.com";
string sourcePath = "Some Source Path";

// act
sinkNodeResource.CopyToUserSession(uri, sourcePath);

// assert
dataAccessApi.AssertWasCalled(
    x => x.Request<object>(
        Arg<RestRequest>.Matches(
            y => y.Method == Method.POST && 
                 y.Resource == uri &&
                 y.Parameters.Count == 1 &&
                 y.Parameters[0].Value as string == sourcePath
        ),
        Arg<Action<object>>.Is.Equal((Action<object>)restExecution.Get)
    )
);