Autofac: Can't inject SignalR strongly-typed HubContext

[ahocquet]

Possibly related to #972

Since Autofac version 4.9.3, I can't inject anymore a SignalR strongly-typed HubContext in the form of IHubContext<Hub, IHub>. I can't reproduce the issue when I'm on version 4.9.2.

Version used:

• Autofac Version="4.9.3"
• Autofac.Extensions.DependencyInjection Version="4.4.0"
• Microsoft.AspNetCore.SignalR Version="1.1.0"

Stack Trace
Message: This operation is only valid on generic types.

   at System.RuntimeType.GetGenericTypeDefinition()
   at Autofac.Util.TypeExtensions.ParameterCompatibleWithTypeConstraint(Type parameter, Type constraint) in C:\\projects\\autofac\\src\\Autofac\\Util\\TypeExtensions.cs:line 193
   at Autofac.Util.TypeExtensions.<>c__DisplayClass7_1.<IsCompatibleWithGenericParameterConstraints>b__1(Type constraint) in C:\\projects\\autofac\\src\\Autofac\\Util\\TypeExtensions.cs:line 83
   at System.Linq.Enumerable.Any[TSource](IEnumerable`1 source, Func`2 predicate)
   at Autofac.Util.TypeExtensions.IsCompatibleWithGenericParameterConstraints(Type genericTypeDefinition, Type[] parameters) in C:\\projects\\autofac\\src\\Autofac\\Util\\TypeExtensions.cs:line 81
   at Autofac.Features.OpenGenerics.OpenGenericServiceBinder.TryBindServiceType(Service service, IEnumerable`1 configuredOpenGenericServices, Type openGenericImplementationType, Type& constructedImplementationType, Service[]& constructedServices) in C:\\projects\\autofac\\src\\Autofac\\Features\\OpenGenerics\\OpenGenericServiceBinder.cs:line 57
   at Autofac.Features.OpenGenerics.OpenGenericRegistrationSource.RegistrationsFor(Service service, Func`2 registrationAccessor)+MoveNext()
   at Autofac.Core.Registration.ComponentRegistry.GetInitializedServiceInfo(Service service) in C:\\projects\\autofac\\src\\Autofac\\Core\\Registration\\ComponentRegistry.cs:line 360
   at Autofac.Core.Registration.ComponentRegistry.TryGetRegistration(Service service, IComponentRegistration& registration) in C:\\projects\\autofac\\src\\Autofac\\Core\\Registration\\ComponentRegistry.cs:line 128
   at Autofac.ResolutionExtensions.TryResolveService(IComponentContext context, Service service, IEnumerable`1 parameters, Object& instance) in C:\\projects\\autofac\\src\\Autofac\\ResolutionExtensions.cs:line 1035
   at Autofac.ResolutionExtensions.ResolveOptionalService(IComponentContext context, Service service, IEnumerable`1 parameters) in C:\\projects\\autofac\\src\\Autofac\\ResolutionExtensions.cs:line 814
   at Microsoft.Extensions.DependencyInjection.ActivatorUtilities.GetService(IServiceProvider sp, Type type, Type requiredBy, Boolean isDefaultParameterRequired)
   at lambda_method(Closure , IServiceProvider , Object[] )
   at Microsoft.AspNetCore.Mvc.Controllers.ControllerActivatorProvider.<>c__DisplayClass4_0.<CreateActivator>b__0(ControllerContext controllerContext)
   at Microsoft.AspNetCore.Mvc.Controllers.ControllerFactoryProvider.<>c__DisplayClass5_0.<CreateControllerFactory>g__CreateController|0(ControllerContext controllerContext)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeInnerFilterAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextResourceFilter()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Rethrow(ResourceExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeFilterPipelineAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeAsync()
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.Invoke(HttpContext httpContext)
   at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext httpContext)
   at SignalRExample.Api.Middlewares.ErrorHandlingMiddleware.Invoke(HttpContext context) in D:\\Source\\autofac-bug\\SignalRExample.Api\\SignalRExample.Api\\Middlewares\\ErrorHandlingMiddleware.cs:line 35

Sample to reproduce the issue:
https://github.com/ahocquet/autofac-bug.git

• Launch the API with Visual Studio 2019
• Go to https://localhost:44353/api/signalr/say-hello (the port 44353 might be different on your computer)

[alistairjevans]

Hey @ahocquet, thanks for the detail, this looks like a duplicate of #1006; we have a pending PR for a 4.9.4 release for this that should resolve your issue once 4.9.4 goes out.

If you want to check now that the existing fix does resolve your issue, you can grab the pre-merge fork from https://github.com/alistairjevans/Autofac/tree/v4.9.4, reference that and retry your scenario.

[ahocquet]

Hi @alistairjevans, sorry I've missed that dup, I was only looking from currently opened issues.

I've tested your fork and it fixes the issue, good job!

[alistairjevans]

No worries, good to know; 4.9.4 has now been released by the way.

[ahocquet]

Nice, thank you !!