cant annotate string literal `'`, `"`

[haolian9]

How are you using the lua-language-server?

NeoVim

Which OS are you using?

Linux

What is the issue affecting?

Annotations

Expected Behaviour

given this snippet, luals knows it's a single quote.

local x = "'"

but if i try to annotate it as follow,

---@type "'"
local x = "'"

luals complains: 'Cannot assign string to "".^@- string cannot match ""^@- Literal '"' cannot match string ""'

Actual Behaviour

luals does not recognize ---@type "'"

Reproduction steps

1. Go to '...'
2. Click '...'
3. See error '...'

Additional Notes

No response

Log File

No response

[tomlau10]

I tested and confirmed this 👍
After some debugging, this seems to be related to the compatibility of quotes usage in the parseString() function here:

lua-language-server/script/parser/luadoc.lua

Lines 674 to 681 in ddc96bd

	-- compatibility
	if content:sub(1, 1) == '"'
	or content:sub(1, 1) == "'" then
	if content:sub(1, 1) == content:sub(-1, -1) then
	mark = content:sub(1, 1)
	content = content:sub(2, -2)
	end
	end

I suppose this logic is to handle the following string definitions (for compatibilty reason):

• ---@type '"a"'
  • parsed content = "a"
  • strip the quotes => a
• ---@type "'a'"
  • parsed content = 'a'
  • strip the quotes => a

However as you can see, the above logic used content:sub(2, -2) to strip the surrounding quotes. So when the content is just a single character ', this logic fails and returns empty string.
(this content is of length 1, so doing substring on index 2 is just empty)

---

A simple fix is to check #content > 1 before doing the quotes stripping.

if content:sub(1, 1) == '"'
or content:sub(1, 1) == "'" then
    -- try stripping quotes only if content string length > 1
    if #content > 1 and content:sub(1, 1) == content:sub(-1, -1) then
        ...

(or even add this check in the outer if, but that will modify more lines)

I suggest you can open a PR after testing it 😄