bug#59633: 29.0.50; tree-sitter-bash: Incorrect behaviour of heredocs with expansions

[Yuan Fu <casouri@gmail.com>]

miha@kamnitnik.top writes:

> 1. Visit empty buffer test in fundamental mode (C-x b test RET)
> 2. Insert
>
> tee << EOF
> text1 $var
> text2 $(echo cmd)
> text3
> $var2
> EOF
>
> 3. Put point before "text2"
> 4. M-x load-library RET treesit RET
> 5. M-: (treesit-node-children (treesit-node-at (point) 'bash))
>
>     => (#<treesit-node (simple_expansion) in 18-22>
>         #<treesit-node (command_substitution) in 29-40>)
>
>    Note that this list is incorrect, "$var2" at the end of heredoc is
>    missing.
>
> 6. M-: (treesit-node-first-child-for-pos (treesit-node-at (point) 'bash) (point))
>
>    => nil
>
>    Expected return value here is #<treesit-node (command_substitution) in 29-40>
>
> I'm not sure if this bug is on Emacs, tree-sitter-bash or even
> tree-sitter itself and I don't know how to check.
>
> tree-sitter-bash version: 0.19.0.r19.g77cf8a7-1
> tree-sitter version: 0.20.7-1
>
> Thanks and best regards.

Thanks. This is the tree produced by tree-sitter, does it match your
expectation?

(heredoc_body
(simple_expansion $ (variable_name))
(command_substitution $(
  (command
   name: (command_name (word))
   argument: (word))
  ))
(simple_expansion $ (variable_name)))

treesit-node-at gives you the _smallest_ node at point, maybe that’s why
you didn’t see expected behavior?

Yuan