fix: Use only filetype tree for generation (#26)

lua/neogen.lua

@@ -1,6 +1,7 @@
 local ok, ts_utils = pcall(require, "nvim-treesitter.ts_utils")
 assert(ok, "neogen requires nvim-treesitter to operate :(")
 
+---@diagnostic disable-next-line: lowercase-global
 neogen = {}
 
 -- Require utilities
@@ -18,8 +19,12 @@ neogen.generate = function(opts)
     opts = opts or {
         type = "func",
     }
-    vim.treesitter.get_parser(0):for_each_tree(function(tree, language_tree)
-        local language = neogen.configuration.languages[language_tree:lang()]
+
+    local parser = vim.treesitter.get_parser(0, vim.bo.filetype)
+    local tstree = parser:parse()[1]
+    local tree = tstree:root()
+
+    local language = neogen.configuration.languages[vim.bo.filetype]
 
     if language then
         language.locator = language.locator or neogen.default_locator
@@ -32,7 +37,7 @@ neogen.generate = function(opts)
 
         -- Use the language locator to locate one of the required parent nodes above the cursor
         local located_parent_node = language.locator({
-                root = tree:root(),
+            root = tree,
             current = ts_utils.get_node_at_cursor(0),
         }, language.parent[opts.type])
 
@@ -102,7 +107,6 @@ neogen.generate = function(opts)
             end
         end
     end
-    end)
 end
 
 function neogen.jump_next()