Many things are working

lua/plugins/treesitter.lua

@@ -0,0 +1,56 @@
+return {
+  "nvim-treesitter/nvim-treesitter",
+  dependencies = { "windwp/nvim-ts-autotag", "JoosepAlviste/nvim-ts-context-commentstring" },
+  init = function()
+    U.cmd_executable("tree-sitter", {
+      [false] = function()
+        vim.notify("tree-sitter not installed, code syntax will be broken.", 2)
+      end,
+    })
+  end,
+  event = "BufRead",
+  cmd = {
+    "TSBufDisable",
+    "TSBufEnable",
+    "TSBufToggle",
+    "TSDisable",
+    "TSEnable",
+    "TSToggle",
+    "TSInstall",
+    "TSInstallInfo",
+    "TSInstallSync",
+    "TSModuleInfo",
+    "TSUninstall",
+    "TSUpdate",
+    "TSUpdateSync",
+  },
+  opts = function()
+    local nonNixOpts = {}
+    if not NIX then
+      nonNixOpts = {
+        ensure_installed = "all",
+      }
+    end
+    return U.assign({
+      highlight = {
+        enable = true,
+        use_languagetree = true,
+        disable = function(_, bufnr)
+          return vim.api.nvim_buf_line_count(bufnr) > 10000
+        end,
+        -- additional_vim_regex_highlighting = false,
+      },
+      incremental_selection = { enable = true },
+      ident = { enable = true },
+      autotag = { enable = true },
+      rainbow = {
+        enable = true,
+        extended_mode = true,
+        max_file_lines = nil,
+      },
+    }, nonNixOpts)
+  end,
+  config = function(_, opts)
+    require("nvim-treesitter.configs").setup(opts)
+  end,
+}