fix: checking for winid value before to evoke it

[victorfds]

To handle the error below:

I noticed in the original code that the winid property was invoked (with ()) even when it was nil.
The refined code incorporates a validation step to ensure that the function is called exclusively when a valid value is present.

[j-hui]

Sorry for not getting to this sooner. But it's odd to me that this is necessary, since this function is quite clearly documented in the API: https://github.com/nvim-tree/nvim-tree.lua/blob/f39f7b6fcd3865ac2146de4cb4045286308f2935/doc/nvim-tree-lua.txt#L1720-L1730

Can you please let me know which version of nvim-tree you are using?

[victorfds]

Thank you for answering me.
Sure!
My nvim-tree version is 0.99.

[j-hui]

Can you please give me a minimal nvim config that reproduces this issue? I'm not able to reproduce it myself, using nvim-tree with tag = "v0.99".

I don't see any reason for the winid function to be missing, and I'd rather not add spurious checks where unnecessary because it clutters the code.

[victorfds]

Sure.
I installed LunarVim.
After that, copied the Rust settings config.lua from https://github.com/LunarVim/starter.lvim/tree/rust-ide to my lvim custom file.
Then, the bug appeared.

[j-hui]

Is the problem unique to using LunarVim? If not, can you please provide a minimal config that does not involve installing a whole Neovim distro?

[j-hui]

I ended up digging into this myself, and found the issue: LunarVim does not use rolling plugin releases, and instead uses the commit hashes from its snapshots.json file (which essentially acts as a lock file). On v1.3.0 of LunarVim, that file is 10 months out of date at this point, and points to commit nvim-tree/nvim-tree.lua@bb375fb of nvim-tree.lua.

So in fact, you are probably not on v0.99 of nvim-tree, which was released on Dec 31, 2023. (I say "probably" because I find it odd that nvim-tree does not have any other releases aside from v0.99, so perhaps I misunderstand their versioning model and "previously released" v0.99 and later moved the tag forward on NYE.)

Since this means there are users of outdated nvim-tree, we should indeed check for whether winid is defined. However, doing so in each callback is really unnecessary---instead, we can simply not register the callback in the first place if the function doesn't exist. I'll go ahead and update the PR and merge it.

[gegoune]

You are correct, @j-hui, 0.99 is the only ever released version of nvim-tree.

[j-hui]

@victorfds please pull and make sure that this fixes your issue. If so, I'll go ahead and merge.

[victorfds]

It works perfectly!