RegisterTypes will attempt to register abstract types (undocumented breaking change in v6.5.0) #1388
Description
Describe the Bug
In Autofac v6.4.0, a scanning registration using RegisterTypes that includes types that cannot be constructed (e.g. interfaces, abstract classes) will work fine.
In Autofac v6.5.0 onwards, it will attempt to register those non-constructible types resulting in an Autofac.Core.Activators.Reflection.NoConstructorsFoundException upon building the container.
This is a breaking change that I couldn't find documented anywhere.
Steps to Reproduce
public class ReproTest
{
interface IInterface { }
class Class : IInterface
{
}
[Fact]
public void Repro()
{
var containerBuilder = new ContainerBuilder();
containerBuilder
.RegisterTypes(typeof(IInterface), typeof(Class))
.AssignableTo<IInterface>();
var exception = Record.Exception(() => containerBuilder.Build());
Assert.Null(exception);
}
}Expected Behavior
No exception, test passes (v6.4.0 behaviour)
Exception with Stack Trace
v6.5.0 onwards throws:
Autofac.Core.Activators.Reflection.NoConstructorsFoundException: No accessible constructors were found for the type 'ReproTestProject.ReproTest+IInterface'.
at Autofac.Core.Activators.Reflection.DefaultConstructorFinder.GetDefaultPublicConstructors(Type type)
at Autofac.Core.Activators.Reflection.DefaultConstructorFinder.FindConstructors(Type targetType)
at Autofac.Core.Activators.Reflection.ReflectionActivator.ConfigurePipeline(IComponentRegistryServices componentRegistryServices, IResolvePipelineBuilder pipelineBuilder)
at Autofac.Core.Registration.ComponentRegistration.BuildResolvePipeline(IComponentRegistryServices registryServices, IResolvePipelineBuilder pipelineBuilder)
at Autofac.Core.Registration.ComponentRegistration.BuildResolvePipeline(IComponentRegistryServices registryServices)
at Autofac.Core.Registration.ComponentRegistryBuilder.Build()
at Autofac.ContainerBuilder.Build(ContainerBuildOptions options)
at ReproTestProject.ReproTest.<>c__DisplayClass2_0.<Repro>b__0()
Dependency Versions
Autofac: v6.5.0
Additional Info
A workaround is for the user to filter out abstract types from the types passed to RegisterTypes themselves.
In trying to figure out why I was getting this exception after upgrading to v6.5.0 from v6.4.0 I took a look at the diff between the two versions, and the removal of !t.IsAbstract in CanBeRegistered in this commit was something that stood out to me that might be the cause.