chore(nvim): improve configuration for nvim-ufo

nvim/lua/plugins/ufo.lua

@@ -4,13 +4,48 @@ return {
   "kevinhwang91/nvim-ufo",
   dependencies = "kevinhwang91/promise-async",
   config = function()
-    vim.o.foldcolumn = "1"
+    vim.o.fillchars = [[eob: ,fold: ,foldopen:,foldsep: ,foldclose:]]
+    vim.o.foldcolumn = "0"
     vim.o.foldlevel = 99
-    vim.o.foldlevelstart = 99
+    vim.o.foldlevelstart = 100
     vim.o.foldenable = true
 
+    local handler = function(virtText, lnum, endLnum, width, truncate)
+      local newVirtText = {}
+      local suffix = (" 󰁂 %d "):format(endLnum - lnum)
+      local sufWidth = vim.fn.strdisplaywidth(suffix)
+      local targetWidth = width - sufWidth
+      local curWidth = 0
+      for _, chunk in ipairs(virtText) do
+        local chunkText = chunk[1]
+        local chunkWidth = vim.fn.strdisplaywidth(chunkText)
+        if targetWidth > curWidth + chunkWidth then
+          table.insert(newVirtText, chunk)
+        else
+          chunkText = truncate(chunkText, targetWidth - curWidth)
+          local hlGroup = chunk[2]
+          table.insert(newVirtText, { chunkText, hlGroup })
+          chunkWidth = vim.fn.strdisplaywidth(chunkText)
+          if curWidth + chunkWidth < targetWidth then
+            suffix = suffix .. (" "):rep(targetWidth - curWidth - chunkWidth)
+          end
+          break
+        end
+        curWidth = curWidth + chunkWidth
+      end
+      table.insert(newVirtText, { suffix, "MoreMsg" })
+      return newVirtText
+    end
+
     require("ufo").setup({
-      provider_selector = function(bufnr, filetype, bufftype)
+      fold_virt_text_handler = handler,
+      close_fold_kinds_for_ft = {
+        default = { "imports", "comment" },
+      },
+      open_fold_hl_timeout = 300,
+      enable_get_fold_virt_text = false,
+      preview = {},
+      provider_selector = function()
         return { "lsp", "indent" }
       end,
     })