DI behavior change between .NET 7.0 and .NET 8.0

[snowinmars]

Description

Still have the issue on dotnet 8.

See #88968

Reproduction Steps

Reproduction repository: https://github.com/snowinmars/Dotnet8DiBugCase/tree/master

Expected behavior

See in the reproduction repository

Actual behavior

See in the reproduction repository

Regression?

No response

Known Workarounds

No response

Configuration

NET7 > NET8

Other information

No response

[ericstj]

#88968 was closed as by design and the change was documented. You'll need to share more details here.

I'm going to close this as by design, and due to the breaking change above.
If DI needs to work around this issue, please re-open or comment here.

If this was the case you'll need to add more details here to help us understand what you need.

[snowinmars]

The #88968 is about moq di. Current example doesn't involve moq, so maybe it's a different issue. Isn't it?

I don't see any breaking changes doc, attached to the #88968 . Where can I read them?

[steveharter]

The breaking change doc is at dotnet/docs#36725.

[snowinmars-debug]

Yea, I saw this doc before. There is an issue: neither I nor Castle afais uses HasDefaultValue property on DefineConstructor()/DefineMethod() result.

[steveharter]

Castle uses IL.Emit which in v6 and earlier used to add a null default value to each argument of a method. Starting in v7, IL.Emit doesn't do that by default.

Closing this issue. A Castle bug should be created so it can be fixed for that. The fix would be to either add an empty constructor, or add default values to arguments via [Optional, DefaultParameterValue(null)] attributes.

Running this below shows the behavior difference:

            var services = new ServiceCollection();

            services.AddScopedWithInterceptors<ITestService, TestService, TestInterceptor>();
            var b = services.BuildServiceProvider();

            ServiceDescriptor sd = services[1];
            // v6:
            // Implementation type: ITestServiceProxy
            // Orig Arg 1 serviceType False
            // Impl Arg 1  True
            // Orig Arg 2 serviceKey False
            // Impl Arg 2  True
            // Orig Arg 3 implementationType False
            // Impl Arg 3  True

            // v7+:
            // Implementation type: ITestServiceProxy
            // Orig Arg 1 serviceType False
            // Impl Arg 1  False
            // Orig Arg 2 serviceKey False
            // Impl Arg 2  False
            // Orig Arg 3 implementationType False
            // Impl Arg 3  False
            Console.WriteLine($"Implementation type: {sd.ImplementationType!.Name}");
            Console.WriteLine($"Orig Arg 1 {sd.GetType().GetConstructors()[1].GetParameters()[0].Name} {sd.GetType().GetConstructors()[1].GetParameters()[0].HasDefaultValue}");
            Console.WriteLine($"Impl Arg 1 {sd.ImplementationType.GetConstructors()[0].GetParameters()[0].Name} {sd.ImplementationType.GetConstructors()[0].GetParameters()[0].HasDefaultValue}");
            Console.WriteLine($"Orig Arg 2 {sd.GetType().GetConstructors()[1].GetParameters()[1].Name} {sd.GetType().GetConstructors()[1].GetParameters()[1].HasDefaultValue}");
            Console.WriteLine($"Impl Arg 2 {sd.ImplementationType.GetConstructors()[0].GetParameters()[1].Name} {sd.ImplementationType.GetConstructors()[0].GetParameters()[1].HasDefaultValue}");
            Console.WriteLine($"Orig Arg 3 {sd.GetType().GetConstructors()[1].GetParameters()[2].Name} {sd.GetType().GetConstructors()[1].GetParameters()[2].HasDefaultValue}");
            Console.WriteLine($"Impl Arg 3 {sd.ImplementationType.GetConstructors()[0].GetParameters()[2].Name} {sd.ImplementationType.GetConstructors()[0].GetParameters()[2].HasDefaultValue}");


            var service = b.GetService<ITestService>();
            System.Console.WriteLine(service.DoTest());