fix(treesitter): is_in_node_range (#22582)

TS ranges are end column exclusive, so fix is_in_node_range
to account for that.

2 files changed, 20 insertions, 2 deletions

diff --git a/runtime/lua/vim/treesitter.lua b/runtime/lua/vim/treesitter.lua
index d13824076e..ab9f8968c8 100644
--- a/runtime/lua/vim/treesitter.lua
+++ b/runtime/lua/vim/treesitter.lua
@@ -191,7 +191,7 @@ end
 ---
 ---@return boolean True if the position is in node range
 function M.is_in_node_range(node, line, col)
-  return M.node_contains(node, { line, col, line, col })
+  return M.node_contains(node, { line, col, line, col + 1 })
 end
 
 --- Determines if a node contains a range
@@ -202,7 +202,8 @@ end
 ---@return boolean True if the {node} contains the {range}
 function M.node_contains(node, range)
   vim.validate({
-    node = { node, 'userdata' },
+    -- allow a table so nodes can be mocked
+    node = { node, { 'userdata', 'table' } },
     range = { range, Range.validate, 'integer list with 4 or 6 elements' },
   })
   return Range.contains({ node:range() }, range)
diff --git a/test/functional/treesitter/utils_spec.lua b/test/functional/treesitter/utils_spec.lua
index 7f5a864c3d..9c07959098 100644
--- a/test/functional/treesitter/utils_spec.lua
+++ b/test/functional/treesitter/utils_spec.lua
@@ -28,4 +28,21 @@ describe('treesitter utils', function()
     eq(true, exec_lua('return vim.treesitter.is_ancestor(ancestor, child)'))
     eq(false, exec_lua('return vim.treesitter.is_ancestor(child, ancestor)'))
   end)
+
+  it('can detect if a position is contained in a node', function()
+    exec_lua([[
+      node = {
+        range = function()
+          return 0, 4, 0, 8
+        end,
+      }
+    ]])
+
+    eq(false, exec_lua('return vim.treesitter.is_in_node_range(node, 0, 3)'))
+    for i = 4, 7 do
+      eq(true, exec_lua('return vim.treesitter.is_in_node_range(node, 0, ...)', i))
+    end
+    -- End column exclusive
+    eq(false, exec_lua('return vim.treesitter.is_in_node_range(node, 0, 8)'))
+  end)
 end)