feat(treesitter): add node_for_range function

This is identical to `named_node_for_range` except that it includes
anonymous nodes. This maintains consistency in the API because we
already have `descendant_for_range` and `named_descendant_for_range`.

4 files changed, 37 insertions, 1 deletions

diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index 2514ee8a92..2ddda72ae8 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -166,7 +166,7 @@ TERMINAL
 
 TREESITTER
 
-• TODO
+• |LanguageTree:node_for_range()| gets anonymous and named nodes for a range
 
 TUI
 
diff --git a/runtime/doc/treesitter.txt b/runtime/doc/treesitter.txt
index 2249f4865c..cd8a4d8ec5 100644
--- a/runtime/doc/treesitter.txt
+++ b/runtime/doc/treesitter.txt
@@ -1375,6 +1375,19 @@ LanguageTree:named_node_for_range({range}, {opts})
     Return: ~
         (`TSNode?`)
 
+                                               *LanguageTree:node_for_range()*
+LanguageTree:node_for_range({range}, {opts})
+    Gets the smallest node that contains {range}.
+
+    Parameters: ~
+      • {range}  (`Range4`) `{ start_line, start_col, end_line, end_col }`
+      • {opts}   (`table?`) A table with the following fields:
+                 • {ignore_injections}? (`boolean`, default: `true`) Ignore
+                   injected languages
+
+    Return: ~
+        (`TSNode?`)
+
 LanguageTree:parse({range})                             *LanguageTree:parse()*
     Recursively parse all regions in the language tree using
     |treesitter-parsers| for the corresponding languages and run injection
diff --git a/runtime/lua/vim/treesitter/languagetree.lua b/runtime/lua/vim/treesitter/languagetree.lua
index 3523ea95e0..03803f5869 100644
--- a/runtime/lua/vim/treesitter/languagetree.lua
+++ b/runtime/lua/vim/treesitter/languagetree.lua
@@ -1133,6 +1133,18 @@ function LanguageTree:tree_for_range(range, opts)
   return nil
 end
 
+--- Gets the smallest node that contains {range}.
+---
+---@param range Range4 `{ start_line, start_col, end_line, end_col }`
+---@param opts? vim.treesitter.LanguageTree.tree_for_range.Opts
+---@return TSNode?
+function LanguageTree:node_for_range(range, opts)
+  local tree = self:tree_for_range(range, opts)
+  if tree then
+    return tree:root():descendant_for_range(unpack(range))
+  end
+end
+
 --- Gets the smallest named node that contains {range}.
 ---
 ---@param range Range4 `{ start_line, start_col, end_line, end_col }`
diff --git a/test/functional/treesitter/language_spec.lua b/test/functional/treesitter/language_spec.lua
index 40c974beee..e71c39244f 100644
--- a/test/functional/treesitter/language_spec.lua
+++ b/test/functional/treesitter/language_spec.lua
@@ -148,4 +148,15 @@ describe('treesitter language API', function()
 
     eq('<node primitive_type>', exec_lua('return tostring(node)'))
   end)
+
+  it('retrieve an anonymous node given a range', function()
+    insert([[vim.fn.input()]])
+
+    exec_lua([[
+      langtree = vim.treesitter.get_parser(0, "lua")
+      node = langtree:node_for_range({0, 3, 0, 3})
+    ]])
+
+    eq('.', exec_lua('return node:type()'))
+  end)
 end)