Rhino.Mocks - the basics

Started using Rhino.Mocks recently (Awesome!!!) - just wanted to list a few of the basics; the official Rhino Mocks Documentation is very good and available here. These examples are a bit rough, they have not been compiled; there may be typos.

using

using Rhino.Mocks;

The mock repository
<br />// use the mock repository to create the mocked objects<br />MockRepository mocks = new Rhino.Mocks.MockRepository();<br />// example<br />System.Object someObject = mocks.CreateMock<System.Object>();<br />// set up the behaviour you want from calls to your mocked object <br />Rhino.Mocks.Expect.Call(someObject.Equals(someParameter)).Return(false);<br />// then don't forget<br />mocks.ReplayAll();<br />// now do stuff that calls your mocked object Equals method<br />...<br />

Mock a call to the db
<br />// create our mocked repository object - IProductRepository, the real one calls the db<br />IProductRepository repository = mocks.CreateMock<IProductRepository>();<br />// tell rhino.mocks when we call the method GetProduct with the argument 33 to return null<br />Rhino.Mocks.Expect.Call(repository.GetProduct(33)).Return(null);<br />// get the mocking ready<br />mocks.ReplayAll();<br />// pass our mock to our product service layer<br />ProductService service = new ProductService(repository);<br />// service.GetProduct makes a call to the mocked repository.GetProduct which will return null<br />IProduct product = service.GetProduct(33);<br />// should be null<br />Assert.IsNull(product);<br />

Ignore any arguments
<br />// any call to GetProduct will return null no matter the value of the arg<br />Rhino.Mocks.Expect.Call(repository.GetProduct(null)).Return(null).IgnoreArguments();<br />

mock a method that returns void
<br />IProduct product = new Product("003092", "Sierra Nevada", 6.49);<br />// this void call will handle our product 003092<br />Rhino.Mocks.Expect.Call(delegate { repository.Save(product); });<br />// this void call will handle any argument<br />Rhino.Mocks.Expect.Call(delegate { repository.Save(null); }).IgnoreArguments();<br />

Handle multiple calls to the same method
<br />IProduct product = new Product("003092", "Sierra Nevada", 6.49);<br />// note the .Repeat.Any()<br />Rhino.Mocks.Expect.Call(repository.GetProduct("003092")).Return(product).Repeat.Any();<br />// send the mock to our product service object<br />ProductService service = new ProductService(repository);<br />// find by sku calls GetProduct on the mocked Product repository<br />IProduct beer = service.FindBySku("003092");<br />// find decent beer calls GetProduct on the mocked Product repository also<br />IProduct decentBeer = service.FindDecentBeer();<br />

Partial Mock
<br />// create a partial mock with constructor args (our product repository again)<br />IProductService service = mocks.PartialMock<IProductService>(repository);<br />// our test case data<br />IUser loggedOnUser = new User("John", "Doe", CustomerType.Gold);<br />// mock product service calls to GetLoggedOnUser<br />Rhino.Mocks.Expect.Call(service.GetLoggedOnUser()).Return(loggedOnUser);<br />// get the mocking ready<br />mocks.ReplayAll();<br />// now GetDiscount is not a mocked method but it does call the mocked GetLoggedOnUser method<br />decimal discount = service.GetDiscount();<br />// assert the result<br />Assert.AreSame(44.4M, discount, "Gold customer discount not correct?");<br />// NOTE: this will not work (compile) unless the mocked method GetLoggedOnUser is public<br />