Automatically install treesitter parsers

Author: oriori1703

init.lua

@@ -945,23 +945,54 @@ require('lazy').setup({
     branch = 'main',
     -- [[ Configure Treesitter ]] See `:help nvim-treesitter-intro`
     config = function()
-      local parsers = { 'bash', 'c', 'diff', 'html', 'lua', 'luadoc', 'markdown', 'markdown_inline', 'query', 'vim', 'vimdoc' }
-      require('nvim-treesitter').install(parsers)
+      ---@param buf integer
+      ---@param language string
+      ---@return boolean
+      local function treesitter_attach(buf, language)
+        -- check if parser exists before starting highlighter
+        if not vim.treesitter.language.add(language) then
+          return false
+        end
+        -- enables syntax highlighting and other treesitter features
+        vim.treesitter.start(buf, language)
+
+        -- enables treesitter based folds
+        -- for more info on folds see `:help folds`
+        -- vim.wo.foldexpr = 'v:lua.vim.treesitter.foldexpr()'
 
+        -- enables treesitter based indentation
+        vim.bo.indentexpr = "v:lua.require'nvim-treesitter'.indentexpr()"
+        return true
+      end
+
+      local available_parsers = require('nvim-treesitter.config').get_available()
       vim.api.nvim_create_autocmd('FileType', {
-        pattern = parsers,
-        callback = function()
-          -- enables syntax highlighting and other treesitter features
-          vim.treesitter.start()
+        callback = function(args)
+          local buf, filetype = args.buf, args.match
+          local language = vim.treesitter.language.get_lang(filetype)
+          if not language then
+            return
+          end
 
-          -- enables treesitter based folds
-          -- for more info on folds see `:help folds`
-          -- vim.wo.foldexpr = 'v:lua.vim.treesitter.foldexpr()'
+          if not (treesitter_attach(buf, language) or vim.tbl_contains(available_parsers, language)) then
+            return
+          end
 
-          -- enables treesitter based indentation
-          vim.bo.indentexpr = "v:lua.require'nvim-treesitter'.indentexpr()"
+          -- automaically install parser for missing languages
+          -- attempt to install even if it is available accoring to `vim.treesitter.langauge.add()`,
+          -- to ensure the latest version is installed using `nvim-treesitter`, instead of the outdated vendored parser
+          if not vim.tbl_contains(require('nvim-treesitter.config').get_installed 'parsers', language) then
+            -- attempt to start highlighter after installing missing language
+            require('nvim-treesitter.install').install(language):await(function()
+              treesitter_attach(buf, language)
+            end)
+          end
         end,
       })
+
+      -- ensure basic parser are installed
+      local parsers = { 'bash', 'c', 'diff', 'html', 'lua', 'luadoc', 'markdown', 'markdown_inline', 'query', 'vim', 'vimdoc' }
+      require('nvim-treesitter').install(parsers)
     end,
     -- There are additional nvim-treesitter modules that you can use to interact
     -- with nvim-treesitter. You should go explore a few and see what interests you: