Merge pull request #135 from isidentical/starred-expr

Improve handling of starred expression on different contexts
This commit is contained in:
Dave Halter
2020-06-05 12:58:14 +02:00
committed by GitHub
2 changed files with 31 additions and 8 deletions

View File

@@ -713,13 +713,10 @@ class _FutureImportRule(SyntaxRule):
@ErrorFinder.register_rule(type='star_expr')
class _StarExprRule(SyntaxRule):
message = "starred assignment target must be in a list or tuple"
message_iterable_unpacking = "iterable unpacking cannot be used in comprehension"
message_assignment = "can use starred expression only as assignment target"
def is_issue(self, node):
if node.parent.type not in _STAR_EXPR_PARENTS:
return True
if node.parent.type == 'testlist_comp':
# [*[] for a in [1]]
if node.parent.children[1].type in _COMP_FOR_TYPES:
@@ -982,7 +979,7 @@ class _FStringRule(SyntaxRule):
class _CheckAssignmentRule(SyntaxRule):
def _check_assignment(self, node, is_deletion=False, is_namedexpr=False):
def _check_assignment(self, node, is_deletion=False, is_namedexpr=False, is_aug_assign=False):
error = None
type_ = node.type
if type_ == 'lambdef':
@@ -1024,9 +1021,9 @@ class _CheckAssignmentRule(SyntaxRule):
# This is not a comprehension, they were handled
# further above.
for child in second.children[::2]:
self._check_assignment(child, is_deletion, is_namedexpr)
self._check_assignment(child, is_deletion, is_namedexpr, is_aug_assign)
else: # Everything handled, must be useless brackets.
self._check_assignment(second, is_deletion, is_namedexpr)
self._check_assignment(second, is_deletion, is_namedexpr, is_aug_assign)
elif type_ == 'keyword':
if node.value == "yield":
error = "yield expression"
@@ -1069,12 +1066,15 @@ class _CheckAssignmentRule(SyntaxRule):
error = "f-string expression"
elif type_ in ('testlist_star_expr', 'exprlist', 'testlist'):
for child in node.children[::2]:
self._check_assignment(child, is_deletion, is_namedexpr)
self._check_assignment(child, is_deletion, is_namedexpr, is_aug_assign)
elif ('expr' in type_ and type_ != 'star_expr' # is a substring
or '_test' in type_
or type_ in ('term', 'factor')):
error = 'operator'
elif type_ == "star_expr":
if not search_ancestor(node, *_STAR_EXPR_PARENTS) and not is_aug_assign:
self.add_issue(node, message="starred assignment target must be in a list or tuple")
self._check_assignment(node.children[1])
if error is not None:
@@ -1109,7 +1109,7 @@ class _ExprStmtRule(_CheckAssignmentRule):
if self._normalizer.version <= (3, 8) or not is_aug_assign:
for before_equal in node.children[:-2:2]:
self._check_assignment(before_equal)
self._check_assignment(before_equal, is_aug_assign=is_aug_assign)
if is_aug_assign:
target = _remove_parens(node.children[0])

View File

@@ -391,3 +391,26 @@ def test_repeated_kwarg():
)
def test_unparenthesized_genexp(source, no_errors):
assert bool(_get_error_list(source)) ^ no_errors
@pytest.mark.parametrize(
('source', 'no_errors'), [
('*x = 2', False),
('(*y) = 1', False),
('((*z)) = 1', False),
('a, *b = 1', True),
('a, *b, c = 1', True),
('a, (*b), c = 1', True),
('a, ((*b)), c = 1', True),
('a, (*b, c), d = 1', True),
('[*(1,2,3)]', True),
('{*(1,2,3)}', True),
('[*(1,2,3),]', True),
('[*(1,2,3), *(4,5,6)]', True),
('[0, *(1,2,3)]', True),
('{*(1,2,3),}', True),
('{*(1,2,3), *(4,5,6)}', True),
('{0, *(4,5,6)}', True)
]
)
def test_starred_expr(source, no_errors):
assert bool(_get_error_list(source, version="3")) ^ no_errors