def visit_Call(self, node):
positional_final_wildcard = False
for i, n in enumerate(node.args):
if astcheck.is_ast_like(n, ast.Name(id=MULTIWILDCARD_NAME)):
if i + 1 == len(node.args):
# Last positional argument - wildcard may extend to kwargs
positional_final_wildcard = True
node.args = (self._visit_list(node.args[:i]) +
astcheck.listmiddle() +
self._visit_list(node.args[i + 1:]))
# Don't try to handle multiple multiwildcards
break
kwargs_are_subset = False
if positional_final_wildcard and node.starargs is None:
del node.starargs # Accept any (or none) *args
# f(a, ??) -> wildcarded kwargs as well
kwargs_are_subset = True
if kwargs_are_subset or any(k.arg == MULTIWILDCARD_NAME
for k in node.keywords):
template_keywords = [
self.visit(k) for k in node.keywords
if k.arg != MULTIWILDCARD_NAME
]
def kwargs_checker(sample_keywords, path):
sample_kwargs = {k.arg: k.value for k in sample_keywords}
for k in template_keywords:
if k.arg == MULTIWILDCARD_NAME:
continue
if k.arg in sample_kwargs:
astcheck.assert_ast_like(sample_kwargs[k.arg], k.value,
path + [k.arg])
else:
raise astcheck.ASTMismatch(path, "(missing)",
"keyword arg %s" % k.arg)
if template_keywords:
node.keywords = kwargs_checker
else:
# Shortcut if there are no keywords to check
del node.keywords
# Accepting arbitrary keywords, so don't check absence of **kwargs
if node.kwargs is None:
del node.kwargs
# In block contexts, we want to avoid checking empty lists (for optional
# nodes), but here, an empty list should mean that there are no
# arguments in that group. So we need to override the behaviour in
# generic_visit
if node.args == []:
node.args = must_not_exist_checker
if getattr(node, "keywords", None) == []:
node.keywords = must_not_exist_checker
return self.generic_visit(node)
def scan_ast(self, tree):
"""Walk an AST and yield nodes matching pattern.
:param ast.AST tree: The AST in which to search
"""
nodetype = type(self.pattern)
for node in ast.walk(tree):
if isinstance(node, nodetype) and astcheck.is_ast_like(node, self.pattern):
yield node
def _is_multiwildcard(n):
return astcheck.is_ast_like(
n, ast.Expr(value=ast.Name(id=MULTIWILDCARD_NAME)))