Updated method_returns to respect empty method_sources.

scripts/validate_docstrings.py

@@ -504,23 +504,26 @@ def method_source(self):
 
  @property
  def method_returns(self):
- (tree, ) = ast.parse(self.method_source).body
-
- def gather_returns(node):
- gathered = [node] if isinstance(node, ast.Return) else []
- for child in ast.iter_child_nodes(node):
- # Ignore nested functions and its subtrees.
- if not isinstance(child, ast.FunctionDef):
- gathered.extend(gather_returns(child))
- return gathered
- # Walk the tree recursively and gather the return nodes.
- return_values = [r.value for r in gather_returns(tree)]
-
- # Replace NameConstant nodes valued None for None.
- for i, v in enumerate(return_values):
- if isinstance(v, ast.NameConstant) and v.value is None:
- return_values[i] = None
- return return_values
+ tree = ast.parse(self.method_source).body
+ if tree:
+ root = tree[0]
+ def gather_returns(node):
+ gathered = [node] if isinstance(node, ast.Return) else []
+ for child in ast.iter_child_nodes(node):
+ # Ignore nested functions and its subtrees.
+ if not isinstance(child, ast.FunctionDef):
+ gathered.extend(gather_returns(child))
+ return gathered
+ # Walk the tree recursively and gather the return nodes.
+ return_values = [r.value for r in gather_returns(root)]
+
+ # Replace NameConstant nodes valued None for None.
+ for i, v in enumerate(return_values):
+ if isinstance(v, ast.NameConstant) and v.value is None:
+ return_values[i] = None
+ return return_values
+ else:
+ return []
 
  @property
  def first_line_ends_in_dot(self):