Top shelf work here, sir! I don't mind if you leave some of the test code in place for now, as you have some other work on your docket I believe. Let's land this.

• feat: natively poll the terminal width
• feat: add IODecorFill
• feat: IODecorCenter
• feat: make IODecor_Absorber use stringify
• feat: IODecorLeft and IODecorRight
• fix: fallback width on terminals with no reported width

I cannot presently build because hpp/testregister.hpp is absent, but still used. Let me know when you've refactored that out, if you can.

I described this in some more detail here: D527#inline-5319

@vperea It's a good habit to link your Differential to the task it's related to. Here on the task, go to Edit Related Objects... → Edit Revisions.

Great work! I only have one remaining comment.

This should be fine. Be advised, when you do the image for Jammy, you'll need to install Arcanist and arcanist-clang-format-linter manually from source instead, as well as PHP 7.4. But that doesn't apply here.

That's fine.

Good job. However, since you're part of the actual project, you can use the User Story next time.

Remember to address the linter errors. I've added a couple of notes. Are you ready for a full review?

Thanks for your work with this!

Minor feedback.

You're making good progress, but I think you've gotten hung up on a familiar snag.

The title and description both need more context. At a glance, I have no idea what this is about.

There are some other changes still here that don't seem to be related to the goal of the Differential.

Beyond this last detaill, do you feel this is ready to land, @jdtolmie?

Woo!