[Vue] Fold: unexpected behavior in SFC

[mrmerc]

Describe the bug

Treesitter's foldexpr() doesn't work as expected on entering a buffer of a Vue's SFC

Folds are OK only in <template> tag. In <script> and <style> tags there is only one fold on the tag itself. It can be "fixed" by either deleting the tag and applying "undo" operation, or creating the tag. So, I assume, the problem is in the initial parsing.

https://github.com/user-attachments/assets/b8009a8f-2fce-490d-8c76-4917397444bb

To Reproduce

Minimal config for reproduction. Tested both on stable and nightly releases

local lazypath = vim.fn.stdpath("data") .. "/lazy/lazy.nvim"
local uv = vim.uv or vim.loop

if not uv.fs_stat(lazypath) then
	local lazyrepo = "https://github.com/folke/lazy.nvim.git"
	local out = vim.fn.system({ "git", "clone", "--filter=blob:none", "--branch=stable", lazyrepo, lazypath })
	if vim.v.shell_error ~= 0 then
		vim.api.nvim_echo({
			{ "Failed to clone lazy.nvim:\n", "ErrorMsg" },
			{ out, "WarningMsg" },
			{ "\nPress any key to exit..." },
		}, true, {})
		vim.fn.getchar()
		os.exit(1)
	end
end

vim.opt.rtp:prepend(lazypath)

require("lazy").setup({
	spec = {
		{
			"nvim-treesitter/nvim-treesitter",
			event = { "BufReadPre", "BufNewFile" },
			build = ":TSUpdate",
			init = function()
				vim.wo.foldlevel = 99
				vim.wo.foldmethod = "expr"
				vim.wo.foldexpr = "v:lua.vim.treesitter.foldexpr()"
			end,
			config = function()
				local treesitter = require("nvim-treesitter.configs")

				---@diagnostic disable-next-line: missing-fields
				treesitter.setup({
					highlight = {
						enable = true,
					},
					ensure_installed = {
						"javascript",
						"typescript",
						"html",
						"vue",
					},
				})
			end,
		},
	},
})

Sample Vue SFC

<template>
  <div class="first">
    <div class="second">
      <div class="third"></div>
    </div>
  </div>
</template>

<script setup lang="ts">
import { ref } from "vue";

import { Import1 } from "./import1";
import { Import2 } from "./import2";
import { Import3 } from "./import3";

const data = ref<Data>({
  field1: "sad",
});
</script>

<style lang="scss" scoped>
  .first {
    width: 12px;
    height: 12px;
  }
  .second {
    width: 12px;
    height: 12px;
  }
  .third {
    width: 12px;
    height: 12px;
  }
</style>

Expected behavior

All folds in <script> and <style> tags should be available after entering a buffer

Output of :checkhealth nvim-treesitter

nvim-treesitter: require("nvim-treesitter.health").check()

Installation ~
- OK `tree-sitter` found 0.24.4 (parser generator, only needed for :TSInstallFromGrammar)
- OK `node` found v20.11.0 (only needed for :TSInstallFromGrammar)
- OK `git` executable found.
- OK `cc` executable found. Selected from { vim.NIL, "cc", "gcc", "clang", "cl", "zig" }
  Version: Apple clang version 16.0.0 (clang-1600.0.26.4)
- OK Neovim was compiled with tree-sitter runtime ABI version 14 (required >=13). Parsers must be compatible with runtime ABI.

OS Info:
{
  machine = "arm64",
  release = "24.1.0",
  sysname = "Darwin",
  version = "Darwin Kernel Version 24.1.0: Thu Oct 10 21:03:15 PDT 2024; root:xnu-11215.41.3~2/RELEASE_ARM64_T6000"
} ~

Parser/Features         H L F I J
  - c                   ✓ ✓ ✓ ✓ ✓
  - css                 ✓ . ✓ ✓ ✓
  - html                ✓ ✓ ✓ ✓ ✓
  - javascript          ✓ ✓ ✓ ✓ ✓
  - lua                 ✓ ✓ ✓ ✓ ✓
  - markdown            ✓ . ✓ ✓ ✓
  - markdown_inline     ✓ . . . ✓
  - query               ✓ ✓ ✓ ✓ ✓
  - scss                ✓ . ✓ ✓ ✓
  - typescript          ✓ ✓ ✓ ✓ ✓
  - vim                 ✓ ✓ ✓ . ✓
  - vimdoc              ✓ . . . ✓
  - vue                 ✓ . ✓ ✓ ✓

  Legend: H[ighlight], L[ocals], F[olds], I[ndents], In[j]ections
         +) multiple parsers found, only one will be used
         x) errors found in the query, try to run :TSUpdate {lang} ~

Output of nvim --version

NVIM v0.11.0-dev-1335+g3f1d09bc94
Build type: RelWithDebInfo
LuaJIT 2.1.1732813678
Run "nvim -V1 -v" for more info

NVIM v0.10.2
Build type: Release
LuaJIT 2.1.1732813678
Run "nvim -V1 -v" for more info

Additional context

No response

[xvvhang]

same problem.

[hungvx-dev]

Is there any update for this bug?

[hanool]

Same thing happens with svelte sfc. Deleting the tag and applying "undo" operation fixes it.

[ironiq]

Actually very similar happens with PHP sfc. What i've found is that if i run ":set foldmethod=expr" after starting nvim with a given php file, the folding will be good.