Unsupported IBinding implementation after migration on 11.1

[ds1709]

Describe the bug

I have custom IBinding implementation, based on math expressions. After migrating from versio 11.0 to 11.1 I got Unsupported IBinding implementation exception becaus my MathExpressionBinding doesn't implement IBinding2 interface. How can I implement it if it's internal, how can I implement any custom IBinding? Also I can't inherits from BindingBase because I cant implement it's private protected members. Version 11.1 is backward incompatible with 11.0, it breaks binary compatibility, it breaks behavior compatibility, it breaks sematic versioning principles. It must be 12.0, but not 11.1. It's fully incompatible with 11.0.

To Reproduce

Just try to implement IBinding2 interface.

Expected behavior

No response

Avalonia version

11.1.2

OS

No response

Additional context

No response

[kekekeks]

How exactly did you manage to implement an interface marked with [NotClientImplementable]? We are injecting special non-implementable methods to our ref assemblies to prevent that

[ds1709]

Interface IBinding is not NotClientImplementable, it works in version 11.0.*. But it throws exception in version 11.1.*. It's backward compatibility violation, and it must be major version update, not minor.

[grokys]

https://github.com/AvaloniaUI/Avalonia/blob/11.0.13/src/Avalonia.Base/Data/IBinding.cs#L8

[grokys]

See also: #15270

[kekekeks]

It's marked as such at least since 11.0.0-preview1. I think our injected method no longer prevents Roslyn from building the assembly.

[ds1709]

Seems like we're talking about different things...
https://semver.org

If you have a huge audience that will be drastically impacted by changing the behavior back to what the public API intended, then it may be best to perform a major version release, even though the fix could strictly be considered a patch release.

It doesn't matter mark you it like NotClientImplementable, you are changing behavior compatibility, it MUST be major update, version 12.0.
Also, in version 11.0.11 I implemented my own MathExpressionBinding : IBinding and it works fine.

[kekekeks]

Those interfaces aren't supposed to be implementable from user code. We've had measures to prevent those from being implemented, but those aren't working with the new SDK since roslyn now ignores internal interface members in our ref assemblies.

IBinding not working when implemented by user code is expected.

[ds1709]

IBinding not working when implemented by user code is expected.

My own binding works as expected, and implementing my own binding was the best solution in my case.

If you want to prevent user code from implementing interface, just make it internal (like IBinding2), or mark it with ObsoleteAttribute. Yes, making public interface internal breaks API and ABI compatibility, but breaking behavior is the worst of all.