Error when using braces on `bind-key` expression

[datwaft]

Hello!

As your parser was added to the nvim-treesitter repository I tried to test it but saw some erroneous behavior when using braces on bind-key expressions.

Example

See the following code snippet, extracted from my dotfiles:

bind -n M-Left { select-pane -L; }
# I am a comment

It creates the following tree:

(file ; [0, 0] - [2, 0]
  (ERROR ; [0, 0] - [1, 16]
    (command) ; [0, 0] - [0, 4]
    (command_line_option) ; [0, 5] - [0, 7]
    (key) ; [0, 8] - [0, 14]
    (select_pane_directive ; [0, 17] - [0, 31]
      (command) ; [0, 17] - [0, 28]
      (command_line_option)) ; [0, 29] - [0, 31]
    (ERROR) ; [0, 31] - [0, 32]
    (ERROR))) ; [1, 2] - [1, 16]

Screenshot

---

My theory is that the issue is with braces in general.

In the man file for tmux you can see the following example:

Braces are parsed as a configuration file (so conditions such as ‘%if’ are processed) and then converted into a string. They are designed to avoid the need for additional escaping when passing a group of tmux commands as an argument (for example to if-shell). These two examples produce an identical command - note that no escaping is needed when using {}:

if-shell true {
    display -p 'brace-dollar-foo: }$foo'
}

if-shell true "display -p 'brace-dollar-foo: }\$foo'"

Braces may be enclosed inside braces, for example:

bind x if-shell "true" {
    if-shell "true" {
        display "true!"
    }
}

[Freed-Wu]

weird, I think it have handled {} specially:

https://github.com/Freed-Wu/tree-sitter-tmux/blob/main/grammar.js#L866

[Freed-Wu]

The bug is not due to { and }, it is due to { and }. For example.

bind -n M-Left {select-pane -L}

will not result in bug.

[Freed-Wu]

If you use \n after {, more complex case is also correct:

if '[[ -d ~/.config/tmux/plugins/fzf-tmux-script ]]' {
  set-hook -g pane-focus-in[10] {
    run -b '~/.config/tmux/plugins/fzf-tmux-script/panes/fzf-panes.tmux \
update_mru_pane_ids'
  }
  bind w run -b '~/.config/tmux/plugins/fzf-tmux-script/panes/fzf-panes.tmux \
new_window'
}

[Freed-Wu]

Braces are parsed as a configuration file (so conditions such as ‘%if’ are processed) and then converted into a string. They are designed to avoid the need for additional escaping when passing a group of tmux commands as an argument (for example to if-shell). These two examples produce an identical command - note that no escaping is needed when using {}:

if-shell true {
display -p 'brace-dollar-foo: }$foo'
}

if-shell true "display -p 'brace-dollar-foo: }$foo'"

Braces may be enclosed inside braces, for example:

bind x if-shell "true" {
if-shell "true" {
display "true!"
}
}

I notice the {} syntax in man page so I thought it muse have a EOL after { and } and never test { and }. It looks like tmux syntax is more flexible than I thought. Currently you can use

bind -n M-Left {
  select-pane -L
}
# I am a comment

to avoid this bug before a final solution is figured out.

[datwaft]

Thank you for your effort!

[benjamin051000]

In a similar fashion, I am getting ERRORs when I use the following text:

I'm not sure if this is related, as this is slightly different than using just curlies. It appears to break the following comments, too. I can open a separate issue if so.

It appears that adding a line with quotes "" (e.g., set -g status-right "...") fixes the comments. So if I place that line before the broken comment, it highlights the comment properly.

[Freed-Wu]

split-window [-bdfhIvPZ] [-c start-directory] [-e environment] [-l size] [-t target-pane] [shell-command] [-F format]
              (alias: splitw)

IMO, split-window can have an optional shell command, so tree-sitter incorrectly think #broken comment is a shell command. Add {, } to tell it the code about split-window have stopped and will not have any shell-command.

In fact, tmux syntax have something I think a little ambiguious, I think it have some more hidden detail to parse tmux code than the manual said.

[benjamin051000]

Okay, looks like adding {}s around some of them work:

But it looks like there are still issues on the cursor position of the conf file (line 38 in the :InspectTree window on the left). Adding curlies to the bind expressions immediately before this line actually fixes the comment on line 12 (# vim-like pane switching with C-hjkl) but does not fix the comment immediately beneath it. If I remove the curlies on bind V and bind S, that line 12 comment breaks:

[benjamin051000]

Some of those curly braces gave me errors, but it could be because I might be on an older version of tmux (v2.6).

[Freed-Wu]

v2.6 is too old! I use 3.3a.