Tweak folding config to allow previewing

lua/plugins/folding.lua

@@ -16,11 +16,36 @@ return {
   -- add nvim-ufo
   {
     "kevinhwang91/nvim-ufo",
-    dependencies = "kevinhwang91/promise-async",
+    dependencies = {
+      "kevinhwang91/promise-async",
+      -- This looks awful, so leaving it disabled
+      -- {
+      --   "luukvbaal/statuscol.nvim",
+      --   config = function()
+      --     local builtin = require("statuscol.builtin")
+      --     require("statuscol").setup({
+      --       relculright = true,
+      --       segments = {
+      --         { text = { builtin.foldfunc }, click = "v:lua.ScFa" },
+      --         { text = { "%s" }, click = "v:lua.ScSa" },
+      --         { text = { builtin.lnumfunc, " " }, click = "v:lua.ScLa" },
+      --       },
+      --     })
+      --   end,
+      -- },
+    },
     event = "BufReadPost",
-    opts = {},
-
+    opts = {
+      provider_selector = function()
+        return { "treesitter", "indent" }
+      end,
+    },
     init = function()
+      vim.o.foldcolumn = "1" -- '0' is not bad
+      vim.o.foldlevel = 99 -- Using ufo provider need a large value, feel free to decrease the value
+      vim.o.foldlevelstart = 99
+      vim.o.foldenable = true
+      vim.o.fillchars = [[eob: ,fold: ,foldopen:,foldsep: ,foldclose:]]
       -- Using ufo provider need remap `zR` and `zM`. If Neovim is 0.6.1, remap yourself
       vim.keymap.set("n", "zR", function()
         require("ufo").openAllFolds()
@@ -30,4 +55,9 @@ return {
       end)
     end,
   },
+  -- Folding preview, by default h and l keys are used.
+  -- On first press of h key, when cursor is on a closed fold, the preview will be shown.
+  -- On second press the preview will be closed and fold will be opened.
+  -- When preview is opened, the l key will close it and open fold. In all other cases these keys will work as usual.
+  { "anuvyklack/fold-preview.nvim", dependencies = "anuvyklack/keymap-amend.nvim", config = true },
 }