fix(health): update to not require nvim-treesitter (#322)

* fix(health): update to not require nvim-treesitter

* add back buffer highlight check

---------

Co-authored-by: Dan Sully <[email protected]>

Author: dsully

lua/render-markdown/health.lua

@@ -21,24 +21,19 @@ function M.check()
         vim.health.error(message)
     end
 
+    M.start('treesitter')
+    M.check_parser('markdown')
+    M.check_parser('markdown_inline')
+
     local latex = state.get(0).latex
     local latex_advice = 'Disable LaTeX support to avoid this warning by setting { latex = { enabled = false } }'
 
-    M.start('nvim-treesitter')
-    local has_treesitter = pcall(require, 'nvim-treesitter')
-    if has_treesitter then
-        vim.health.ok('installed')
-        for _, language in ipairs({ 'markdown', 'markdown_inline' }) do
-            M.check_parser(language)
-            M.check_highlight(language)
-        end
-        if latex.enabled then
-            M.check_parser('latex', latex_advice)
-        end
-    else
-        vim.health.error('not installed')
+    if latex.enabled then
+        M.check_parser('latex', latex_advice)
     end
 
+    M.check_highlight('markdown')
+
     M.start('icons')
     local provider = Icons.provider()
     if provider ~= nil then
@@ -88,8 +83,9 @@ end
 ---@param language string
 ---@param advice? string
 function M.check_parser(language, advice)
-    local parsers = require('nvim-treesitter.parsers')
-    if parsers.has_parser(language) then
+    local has_parser, _ = pcall(vim.treesitter.get_parser, 0, language, { error = false })
+
+    if has_parser then
         vim.health.ok(language .. ': parser installed')
     elseif advice == nil then
         vim.health.error(language .. ': parser not installed')
@@ -101,8 +97,20 @@ end
 ---@private
 ---@param language string
 function M.check_highlight(language)
-    local configs = require('nvim-treesitter.configs')
-    if configs.is_enabled('highlight', language, 0) then
+    --
+    -- As the markdown parser is part of Neovim, and nvim-treesitter no longer provides
+    -- .is_enabled() for the main branch, create a markdown buffer and check the state.
+    --
+    -- See: https://github.com/MeanderingProgrammer/render-markdown.nvim/pull/322#discussion_r1947393569
+    local bufnr = vim.api.nvim_create_buf(false, true)
+
+    vim.bo[bufnr].filetype = language
+
+    local has_highlighter = vim.treesitter.highlighter.active[bufnr] ~= nil
+
+    vim.api.nvim_buf_delete(bufnr, { force = true })
+
+    if has_highlighter then
         vim.health.ok(language .. ': highlight enabled')
     else
         vim.health.error(language .. ': highlight not enabled')