Fix Arguments.arguments so it actually returns all arguments

Closes #2213.

Arguments.arguments() has been modified so that it returns all arguments
as it should (according to its own doc). A test case was also added to
verify this.

astroid/nodes/node_classes.py

@@ -780,7 +780,18 @@ def fromlineno(self) -> int:
  @cached_property
  def arguments(self):
  """Get all the arguments for this node, including positional only and positional and keyword"""
- return list(itertools.chain((self.posonlyargs or ()), self.args or ()))
+ retval = list(itertools.chain((self.posonlyargs or ()), (self.args or ())))
+ if self.vararg:
+ retval.append(
+ Name(self.vararg, -1, -1, self, end_lineno=None, end_col_offset=None)
+ )
+ retval += self.kwonlyargs or ()
+ if self.kwarg:
+ retval.append(
+ Name(self.kwarg, -1, -1, self, end_lineno=None, end_col_offset=None)
+ )
+
+ return retval
 
  def format_args(self, *, skippable_names: set[str] | None = None) -> str:
  """Get the arguments formatted as string.
@@ -910,15 +921,16 @@ def default_value(self, argname):
  :raises NoDefault: If there is no default value defined for the
  given argument.
  """
- args = self.arguments
+ # Ignore *args and **kwargs
+ args = list(filter(lambda x: not isinstance(x, Name), self.arguments))
+ index = _find_arg(argname, self.kwonlyargs)[0]
+ if index is not None and self.kw_defaults[index] is not None:
+ return self.kw_defaults[index]
  index = _find_arg(argname, args)[0]
  if index is not None:
  idx = index - (len(args) - len(self.defaults))
  if idx >= 0:
  return self.defaults[idx]
- index = _find_arg(argname, self.kwonlyargs)[0]
- if index is not None and self.kw_defaults[index] is not None:
- return self.kw_defaults[index]
  raise NoDefault(func=self.parent, name=argname)
 
  def is_argument(self, name) -> bool:
@@ -955,7 +967,9 @@ def find_argname(self, argname, rec=DEPRECATED_ARGUMENT_DEFAULT):
  stacklevel=2,
  )
  if self.arguments:
- return _find_arg(argname, self.arguments)
+ index, argument = _find_arg(argname, self.arguments)
+ if not isinstance(argument, Name):
+ return index, argument
  return None, None
 
  def get_children(self):

astroid/nodes/scoped_nodes/scoped_nodes.py

@@ -963,11 +963,7 @@ def argnames(self) -> list[str]:
  names = [elt.name for elt in self.args.arguments]
  else:
  names = []
- if self.args.vararg:
- names.append(self.args.vararg)
- names += [elt.name for elt in self.args.kwonlyargs]
- if self.args.kwarg:
- names.append(self.args.kwarg)
+
  return names
 
  def infer_call_result(
@@ -1280,11 +1276,7 @@ def argnames(self) -> list[str]:
  names = [elt.name for elt in self.args.arguments]
  else:
  names = []
- if self.args.vararg:
- names.append(self.args.vararg)
- names += [elt.name for elt in self.args.kwonlyargs]
- if self.args.kwarg:
- names.append(self.args.kwarg)
+
  return names
 
  def getattr(

tests/test_nodes.py

@@ -22,6 +22,7 @@
  Uninferable,
  bases,
  builder,
+ extract_node,
  nodes,
  parse,
  test_utils,
@@ -1943,3 +1944,28 @@ def test_str_repr_no_warnings(node):
  test_node = node(**args)
  str(test_node)
  repr(test_node)
+
+
+def test_arguments_contains_all():
+ """Ensure Arguments.arguments actually returns all available arguments"""
+
+ def manually_get_args(arg_node) -> set:
+ names = set()
+ if arg_node.args.vararg:
+ names.add(arg_node.args.vararg)
+ if arg_node.args.kwarg:
+ names.add(arg_node.args.kwarg)
+
+ names.update([x.name for x in arg_node.args.args])
+ names.update([x.name for x in arg_node.args.kwonlyargs])
+
+ return names
+
+ node = extract_node("""def a(fruit: str, *args, b=None, c=None, **kwargs): ...""")
+ assert manually_get_args(node) == {x.name for x in node.args.arguments}
+
+ node = extract_node("""def a(mango: int, b="banana", c=None, **kwargs): ...""")
+ assert manually_get_args(node) == {x.name for x in node.args.arguments}
+
+ node = extract_node("""def a(self, num = 10, *args): ...""")
+ assert manually_get_args(node) == {x.name for x in node.args.arguments}