RegisterAll not variant

Question

I have an interface:

interface IDataHoldingSession<out T>

I want to do the following:

container.RegisterAll<IDataHoldingSession<object>>(
    typeof(IDataHoldingSession<DbContext>), 
    typeof(IDataHoldingSession<PrincipalContext>));

However, this fails with the following exception:

System.ArgumentException: The supplied type IDataHoldingSession<DbContext> does not implement IDataHoldingSession<Object>.

What's the most appropriate way to fix this?

Answer 1

The behavior you're experiencing can be considered a bug in the current Simple Injector 2.3 release. We're working hard to ship 2.4 and I will make sure we fix this for the coming 2.4 release. There are more places in the framework where varient types aren't checked.

In the meantime, you can use the following workaround:

container.RegisterAll(typeof(IDataHoldingSession<object>),
    Lifestyle.Transient.CreateRegistration<IDataHoldingSession<object>>(
        () => container.GetInstance<IDataHoldingSession<string>>(), container),
    Lifestyle.Transient.CreateRegistration<IDataHoldingSession<object>>(
        () => container.GetInstance<IDataHoldingSession<IPlugin>>(), container));

UPDATE

Simple Injector v2.4 has been released. This release fixes this bug.