Add at method to find item on specific line. Add test for at method. Update TODO list.

TODO.md

@@ -2,7 +2,6 @@
 ### Important
-- raise an exception on .find/.find_all if the identifier given doesn't exists
 - .help() seems really slow on big piece of code (for example RedBaron("baron/grammator.py").read())("dict")[0].help() is suuuuuuuuuuuuuuuuper slow)
 - .at() return the first item starting at line X
 - .rename() (name -> value, def/class -> name)

redbaron/base_nodes.py

@@ -212,6 +212,16 @@ class GenericNodesUtils(object):
         else:
             return None
+    def at(self, line_no):
+        if line_no > self.absolute_bounding_box.bottom_right.line or \
+                        line_no < self.absolute_bounding_box.top_left.line:
+            raise IndexError()
+        path = Path.from_baron_path(self, baron.path.position_to_path(self.fst(), (line_no, 1)))
+        node = path.node if path else None
+        if node is not None and hasattr(node, 'type') and node.type == 'endl':
+            return node.next
+        return node
+
     def _string_to_node_list(self, string, parent, on_attribute):
         return NodeList.from_fst(baron.parse(string), parent=parent, on_attribute=on_attribute)
@@ -885,6 +895,7 @@ class Node(GenericNodesUtils):
             'has_render_key',
             'get_absolute_bounding_box_of_attribute',
             'find_by_position',
+            'at',
             'parse_code_block',
             'parse_decorators',
             'from_fst',

tests/test_at.py

+# -*- coding:Utf-8 -*-
+
+"""Test for at method"""
+
+import pytest
+import redbaron
+from redbaron import RedBaron, DecoratorNode, AssignmentNode, DefNode, EndlNode
+
+redbaron.DEBUG = True
+
+fst = RedBaron("""\
+@deco
+
+def foo(a, b):
+    c = a + b
+    e = 1
+""")
+
+
+def test_at():
+    assert isinstance(fst.at(1), DecoratorNode) is True
+    assert isinstance(fst.at(2), RedBaron) is True
+    assert isinstance(fst.at(3), DefNode) is True
+    assert isinstance(fst.at(4), AssignmentNode) is True
+    assert isinstance(fst.at(5), AssignmentNode) is True