Adding bindings in a test project with Ninject.MVC3 - asp.net

Question

I'm having trouble figuring out what the best approach is these days for Ninject and ASP.NET MVC 3.
I have used Install-Package Ninject.MVC3 on my application and have my bootstrap class with the following methods:
public static void Start()
public static void Stop()
private static IKernel CreateKernel()
private static void RegisterServices(IKernel kernel)
It's all great and it loads my modules as expected. But historically what I have done is something like this:
MyApp.dll
Kernel.Bind<ISomething>().To<Something>();
Kernel.Bind<IBlah>().To<Blah>();
Kernel.Bind<IFoo>().To<Foo>();
MyApp.Tests.dll
Here I want to override ONLY ISomething's binding, so I used to just unbind the thing I needed to mock/whatever and rebind:
Kernel.Unbind<ISomething>();
Kernel.Bind<ISomethig>().To<TestSomething>();
But there isn't a method in the Nuget package that implies a thought through way to achieve this with the App_Start class from the original library. If I put another Ninject bootstrap class in my test app it only seems geared up to build a new kernel:
[assembly: WebActivator.PreApplicationStartMethod(typeof(TestNinjectBootstrapper), "Configure")]
I could store the kernel in the original bootstrapper statically and call from the tests project, but this feels wrong. Am I thinking too much and missing something? Or thinking too little :)
Argh. What is a good approach?

Answer 1

To reuse interface/class mapping registration in different project there is ability to create NInject modules. Modules just need to implement the INinjectModule interface, but most should extend the NinjectModule class for simplicity.
So you can place interface/class mapping inside module like in the following example:
public class WarriorModule : NinjectModule
{
public override void Load()
{
Bind<IWeapon>().To<Sword>();
Bind<Samurai>().ToSelf().InSingletonScope();
}
}
After you define such module you can instantiate Kernel with mapping defined in this module.
All that you need is to specify this module as argument during creating Kernel object:
IKernel kernel = new StandardKernel(new WarriorModule());
Note that you can create and instantiate kernel with multiple modules.
So, modules will help you to reuse default mapping configuration. Mapping configuration will be defined in one place which will simplify maintance especially if there are several projects which uses the same interface/class mapping configuration.
There are also some other features like 'Dynamic Module Loading' and etc. More information about modules can be found here.