AsciidoctorJ fails when registering a block processor instance while passing the name as a parameter

[robertpanzer]

To reproduce:
Register a Block processor passing the name as an argument, i.e. by calling this method:

javaExtensionRegistry.block("yell", new MyBlockProcessor());

Rendering a document fails because Asciidoctor calls the name accessor of the extension when classes are registered.
This error affects AsciidoctorJ 1.6.0 only as previously extension instances were registered to Asciidoctor as instances.
This changed with 1.6.0 as now instances are wrapped in a Ruby class per registration.

[mojavelinux]

Will this require a change in Asciidoctor? (either to fix it or to remove unused code?)

[robertpanzer]

No, I can fix it in Asciidoctorj.
I’ll check today if there is a case in
https://github.com/asciidoctor/asciidoctor/blob/master/lib/asciidoctor/extensions.rb that is no longer required by AsciidoctoJ.

[robertpanzer]

I have to admit though I don't fully understand this part of the code:
https://github.com/asciidoctor/asciidoctor/blob/1bf20fc2e8054e7724dc12d0aa26e2a04b871a5a/lib/asciidoctor/extensions.rb#L1397-L1400

First Asciidoctor instantiates the extension passing in the name, and then it calls the accessor again.

[robertpanzer]

While working on this I was wondering if we really want users to implement getName() and setName() on processors.
My understanding is that this was used to interface with Asciidoctor/Ruby as it uses these properties and this bridge called them.
But we should probably deprecate them and require block name registration:

• explicitly in the call to JavaExtensionRegistry.block(name, (instance|class))
• Implicitly via the @Name annotation.

As there are proxies between Asciidoctor/Ruby and the users implementation, there is actually no need for these methods anymore.

[mojavelinux]

I have to admit though I don't fully understand this part of the code:
asciidoctor/asciidoctor:lib/asciidoctor/extensions.rb@1bf20fc#L1397-L1400

The name is optional. The implementation can provide it. The implementation must also self-identify with the same name that was used to create. That's all the code is doing there. It's a lot of edge cases. Some may not apply to AsciidoctorJ.