'$' character in snippet body causes error in 'vsnip#to_string'

[Kamholtz]

The presence of '$' in snippets seems to result in an error and does not expand:

Error executing vim.schedule lua callback: {"result": [false, null, 0], "text": "$('

')"}
stack traceback:
[C]: in function 'vsnip#to_string'
...\site\pack\packer\start\cmp-vsnip/lua/cmp_vsnip/init.lua:40: in function 'resolve'
...-data\site\pack\packer\start\nvim-cmp/lua/cmp/source.lua:348: in function 'resolve'
...m-data\site\pack\packer\start\nvim-cmp/lua/cmp/entry.lua:452: in function 'resolve'
...im-data\site\pack\packer\start\nvim-cmp/lua/cmp/view.lua:225: in function 'fn'
...\site\pack\packer\start\nvim-cmp/lua/cmp/utils/async.lua:41: in function <...\site\pack\packer\start\nvim-cmp/lua/cmp/utils/async.lua:39>

The snippet causing this error:

{
	"JQuery div": {
		"prefix": "jdiv",
		"body": [
			"$('<div />')"
		]
	}
}

Removing the '$' in the body array allows the snippet to expand without error. The snippet as is works in VSCode, so not sure if this is considered a bug or just a difference between VSCode snippets and this plugin. I suspect it is trying to expand the '$' and following characters as if it were a placeholder. Is there a way to escape the '$' in the meantime?

[hrsh7th]

You should escape $ with \\

[dezza]

@hrsh7th hey I saw this and I was wondering why some snippets in bash-language-server like
if-unset-or-null
https://github.com/bash-lsp/bash-language-server/blob/main/server/src/snippets.ts#L527 is escaped

  { # Works
    documentation: 'if unset or null',
    label: 'if-unset-or-null',
    insertText: '"\\${${1:variable}:-${2:default}}"',
  },

while others are not
while-defined

  { # Does not work
    label: 'while-defined',
    documentation: 'while with variable existence check',
    insertText: [
      'while [[ -n "${${1:variable}+x}" ]]',
      '\t${2:command ...}',
      'done',
    ].join('\n'),
  },

The effect of course is that only

while [[ -n "

Is returned, it breaks the snippet expansion completely as well as jumps.

I tested in (reference) vscode just to check, as well as ask my friend who uses coc-lsp (I use yegappan/lsp) how it behaved, but to my surprise, it worked.

These other clients must use some kind of magic interpretation of the tokens to conclude that the outer ${...+x} is not a placeholder, but actual text to be expanded - where vsnip assumes $ is placeholder due to lack of escaping and breaks

Still raises the question why the first snippet if-unset-or-null is properly escaped in that file.. it makes little sense to me, but I trust the bashls maintainers enough not to have overlooked it.

I did this PR, hope they will understand.
bash-lsp/bash-language-server#1258