Auto start and install treesitter for supported languages

nvim/dot-config/nvim/lua/plugins/treesitter.lua

@@ -7,13 +7,10 @@ return {
 		lazy = false,
 		branch = "main",
 		build = ":TSUpdate",
-		-- main = "nvim-treesitter.configs",
-		init = function()
-			vim.wo.foldmethod = "expr"
-			vim.wo.foldexpr = "v:lua.vim.treesitter.foldexpr()"
-			vim.bo.indentexpr = "v:lua.require'nvim-treesitter'.indentexpr()"
-
-			require("nvim-treesitter").install({
+		-- Taken from kickstart.nvim
+		config = function()
+			-- ensure basic parser are installed
+			local parsers = {
 				"c",
 				"cpp",
 				"go",
@@ -32,6 +29,56 @@ return {
 				"cmake",
 				"json",
 				"yaml",
+			}
+			require("nvim-treesitter").install(parsers)
+
+			---@param buf integer
+			---@param language string
+			local function treesitter_try_attach(buf, language)
+				-- Check if the parser exists
+				if not vim.treesitter.language.add(language) then
+					return
+				end
+				vim.treesitter.start(buf, language)
+
+				-- TODO: Does this work properly?
+				local has_fold_query = vim.treesitter.query.get(language, "folds") ~= nil
+				if has_fold_query then
+					vim.wo.foldmethod = "expr"
+					vim.wo.foldexpr = "v:lua.vim.treesitter.foldexpr()"
+				end
+
+				local has_indent_query = vim.treesitter.query.get(language, "indents") ~= nil
+				if has_indent_query then
+					vim.bo.indentexpr = "v:lua.require'nvim-treesitter'.indentexpr()"
+				end
+			end
+
+			local available_parsers = require("nvim-treesitter").get_available()
+			vim.api.nvim_create_autocmd("FileType", {
+				callback = function(args)
+					local buf, filetype = args.buf, args.match
+
+					local language = vim.treesitter.language.get_lang(filetype)
+					if not language then
+						return
+					end
+
+					local installed_parsers = require("nvim-treesitter").get_installed("parsers")
+
+					if vim.tbl_contains(installed_parsers, language) then
+						-- enable the parser if it is installed
+						treesitter_try_attach(buf, language)
+					elseif vim.tbl_contains(available_parsers, language) then
+						-- if a parser is available in `nvim-treesitter` auto install it, and enable it after the installation is done
+						require("nvim-treesitter").install(language):await(function()
+							treesitter_try_attach(buf, language)
+						end)
+					else
+						-- try to enable treesitter features in case the parser exists but is not available from `nvim-treesitter`
+						treesitter_try_attach(buf, language)
+					end
+				end,
 			})
 		end,
 	},