How to align correctly with neo-tree

[RoccoRakete]

You can see the little offset. This is driving me crazy!
Any tips on how to fix that?

[Iron-E]

The separators might be different 🤔 I'll dig into it

[Blackilykat]

Getting this as well with NvimTree, my tree having a different background makes it look like it's off by one cell:

[romgrk]

You need to adjust your vertical separator to use the same character as barbar's tab separator.

[Iron-E]

I've been working on a refactor in my spare time that puts the fillchar separator for the sidebar in the &tabline to address this, which prevents users having to change their config.

The only blocker is that I foresee an situation where someone would have multiple sidebars open on one side, and currently we don't have support for that. I would need to refactor it, and I've been thinking about how best to do that. Might just be out of scope for this issue though.

@romgrk should I throw up an MR with that changeset for review sometime this weekend? Or is changing the separator for the buffer what we want to suggest moving forward?