Neovim: Add custom folding module

.bashrc

@@ -28,6 +28,10 @@ if [ "$BASH" != "" ]; then
     if [ -f /etc/bash_completion ] && ! shopt -oq posix; then
         . /etc/bash_completion
     fi
+
+    if [ -f /usr/share/bash-completion/completions/git ]; then
+        source /usr/share/bash-completion/completions/git
+    fi
 fi
 
 if [[ "${OSTYPE}" == "linux-gnu"* ]]; then

nvim/init.lua

@@ -116,6 +116,13 @@ vim.opt.cursorline = true
 -- Minimal number of screen lines to keep above and below the cursor.
 vim.opt.scrolloff = 10
 
+vim.opt.fillchars = 'fold: '
+vim.wo.foldmethod = 'expr'
+vim.opt.foldlevel = 99
+vim.o.foldexpr = 'nvim_treesitter#foldexpr()'
+--vim.opt.foldtext = 'v:lua.vim.treesitter.foldtext()'
+vim.opt.foldtext = require 'modules.foldtext'
+
 -- [[ Basic Keymaps ]]
 --  See `:help vim.keymap.set()`
 
@@ -457,6 +464,11 @@ require('lazy').setup({
       'hrsh7th/cmp-nvim-lsp',
     },
     config = function()
+      -- Highlight codefences returned from denols.
+      vim.g.markdown_fenced_languages = {
+        'ts=typescript',
+      }
+
       -- LSP provides Neovim with features like:
       --  - Go to definition
       --  - Find references
@@ -569,6 +581,12 @@ require('lazy').setup({
       local capabilities = vim.lsp.protocol.make_client_capabilities()
       capabilities = vim.tbl_deep_extend('force', capabilities, require('cmp_nvim_lsp').default_capabilities())
 
+      -- Tell the server the capability of foldingRange, used by kevinhwang91/nvim-ufo
+      capabilities.textDocument.foldingRange = {
+        dynamicRegistration = false,
+        lineFoldingOnly = true,
+      }
+
       -- Enable the following language servers
       --  Feel free to add/remove any LSPs that you want here. They will automatically be installed.
       --
@@ -593,7 +611,15 @@ require('lazy').setup({
         --    https://github.com/pmizio/typescript-tools.nvim
         --
         -- But for many setups, the LSP (`ts_ls`) will work just fine
-        ts_ls = {},
+        ts_ls = {
+          enabled = true,
+        },
+
+        -- Swap enabled state with ts_ls to use. Theoretically you can also configure these
+        -- to only start when appropriate, but I haven't gotten that working yet.
+        denols = {
+          enabled = false,
+        },
 
         eslint_d = {},
         tailwindcss = {},

nvim/lua/custom/plugins/ufo.lua

@@ -0,0 +1,37 @@
+-- The goal of nvim-ufo is to make Neovim's fold look modern and keep high performance.
+-- https://github.com/kevinhwang91/nvim-ufo
+return {
+  {
+    'kevinhwang91/nvim-ufo',
+    enabled = false,
+    dependencies = {
+      'kevinhwang91/promise-async',
+      'nvim-treesitter/nvim-treesitter',
+      'neovim/nvim-lspconfig',
+    },
+    keys = {
+      {
+        'zR',
+        function()
+          require('ufo').openAllFolds()
+        end,
+      },
+      {
+        'zM',
+        function()
+          require('ufo').closeAllFolds()
+        end,
+      },
+      -- { 'zr', function() require('ufo').openFoldsExceptKinds() end },
+      -- { 'zm', function() require('ufo').closeFoldsWith() end },
+    },
+    opts = function()
+      return {
+        -- More advanced config example: https://github.com/rafi/vim-config/blob/master/lua/rafi/plugins/extras/editor/ufo.lua
+        provider_selector = function(bufnr, filetype, buftype)
+          return { 'treesitter', 'indent' }
+        end,
+      }
+    end,
+  },
+}

nvim/lua/modules/foldtext.lua

@@ -0,0 +1,129 @@
+---@module Foldtext
+---Based on https://www.reddit.com/r/neovim/comments/16sqyjz/finally_we_can_have_highlighted_folds/
+---Retrieved from https://github.com/Wansmer/nvim-config/blob/main/lua/modules/foldtext.lua
+---Updated with vim.treesitter._fold.foldtext()
+
+local function parse_line(linenr)
+  local bufnr = vim.api.nvim_get_current_buf()
+
+  local line = vim.api.nvim_buf_get_lines(bufnr, linenr - 1, linenr, false)[1]
+  if not line then
+    return nil
+  end
+
+  local ok, parser = pcall(vim.treesitter.get_parser, bufnr)
+  if not ok then
+    return nil
+  end
+
+  local query = vim.treesitter.query.get(parser:lang(), 'highlights')
+  if not query then
+    return nil
+  end
+
+  local tree = parser:parse({ linenr - 1, linenr })[1]
+
+  local result = {}
+
+  local line_pos = 0
+
+  for id, node, metadata in query:iter_captures(tree:root(), 0, linenr - 1, linenr) do
+    local name = query.captures[id]
+    local start_row, start_col, end_row, end_col = node:range()
+
+    local priority = tonumber(metadata.priority or vim.highlight.priorities.treesitter)
+
+    if start_row == linenr - 1 and end_row == linenr - 1 then
+      -- check for characters ignored by treesitter
+      if start_col > line_pos then
+        table.insert(result, {
+          line:sub(line_pos + 1, start_col),
+          { { 'Folded', priority } },
+          range = { line_pos, start_col },
+        })
+      end
+      line_pos = end_col
+
+      local text = line:sub(start_col + 1, end_col)
+      table.insert(result, { text, { { '@' .. name, priority } }, range = { start_col, end_col } })
+    end
+  end
+
+  local i = 1
+  while i <= #result do
+    -- find first capture that is not in current range and apply highlights on the way
+    local j = i + 1
+    while j <= #result and result[j].range[1] >= result[i].range[1] and result[j].range[2] <= result[i].range[2] do
+      for k, v in ipairs(result[i][2]) do
+        if not vim.tbl_contains(result[j][2], v) then
+          table.insert(result[j][2], k, v)
+        end
+      end
+      j = j + 1
+    end
+
+    -- remove the parent capture if it is split into children
+    if j > i + 1 then
+      table.remove(result, i)
+    else
+      -- highlights need to be sorted by priority, on equal prio, the deeper nested capture (earlier
+      -- in list) should be considered higher prio
+      if #result[i][2] > 1 then
+        table.sort(result[i][2], function(a, b)
+          return a[2] < b[2]
+        end)
+      end
+
+      result[i][2] = vim.tbl_map(function(tbl)
+        return tbl[1]
+      end, result[i][2])
+      result[i] = { result[i][1], result[i][2] }
+
+      i = i + 1
+    end
+  end
+
+  return result
+end
+
+function HighlightedFoldtext()
+  local result = parse_line(vim.v.foldstart)
+  if not result then
+    return vim.fn.foldtext()
+  end
+
+  local folded = {
+    { ' ', 'FoldedIcon' },
+    { '+' .. vim.v.foldend - vim.v.foldstart .. ' lines', 'FoldedText' },
+    { ' ', 'FoldedIcon' },
+  }
+
+  for _, item in ipairs(folded) do
+    table.insert(result, item)
+  end
+
+  local result2 = parse_line(vim.v.foldend)
+  if result2 then
+    local first = result2[1]
+    result2[1] = { vim.trim(first[1]), first[2] }
+    for _, item in ipairs(result2) do
+      table.insert(result, item)
+    end
+  end
+
+  return result
+end
+
+local function set_fold_hl()
+  local cl = vim.api.nvim_get_hl(0, { name = 'CursorLineNr' })
+  vim.api.nvim_set_hl(0, 'FoldedIcon', { fg = cl.bg })
+  vim.api.nvim_set_hl(0, 'FoldedText', { bg = cl.bg, fg = cl.fg, italic = true })
+end
+
+set_fold_hl()
+
+vim.api.nvim_create_autocmd('ColorScheme', {
+  callback = set_fold_hl,
+})
+
+return 'luaeval("HighlightedFoldtext")()'