def alter_operator(
self, original_op: Union[cst.Equal,
cst.NotEqual]) -> Union[cst.Is, cst.IsNot]:
return (cst.IsNot(
whitespace_before=original_op.whitespace_before,
whitespace_after=original_op.whitespace_after,
) if isinstance(original_op, cst.NotEqual) else cst.Is(
whitespace_before=original_op.whitespace_before,
whitespace_after=original_op.whitespace_after,
))
def visit_BooleanOperation(self, node: cst.BooleanOperation) -> None:
left_expression: cst.BaseExpression = node.left
right_expression: cst.BaseExpression = node.right
if m.matches(node.left, m.Name()):
# Eg: "x and y".
left_expression = cast(cst.Name, left_expression)
if self._is_optional_type(left_expression):
replacement_comparison = self._gen_comparison_to_none(
variable_name=left_expression.value, operator=cst.IsNot()
)
self.report(
node, replacement=node.with_changes(left=replacement_comparison)
)
if m.matches(right_expression, m.Name()):
# Eg: "x and y".
right_expression = cast(cst.Name, right_expression)
if self._is_optional_type(right_expression):
replacement_comparison = self._gen_comparison_to_none(
variable_name=right_expression.value, operator=cst.IsNot()
)
self.report(
node, replacement=node.with_changes(right=replacement_comparison)
)
def replace_not_in_condition(
self, _, updated_node: cst.UnaryOperation) -> cst.BaseExpression:
comparison_node: cst.Comparison = cst.ensure_type(
updated_node.expression, cst.Comparison)
# TODO: Implement support for multiple consecutive 'not ... in B',
# even if it does not make any sense in practice.
return cst.Comparison(
left=comparison_node.left,
lpar=updated_node.lpar,
rpar=updated_node.rpar,
comparisons=[
comparison_node.comparisons[0].with_changes(
operator=cst.IsNot())
],
)
def leave_If(self, original_node: cst.If) -> None:
changes: Dict[str, cst.CSTNode] = {}
test_expression: cst.BaseExpression = original_node.test
if m.matches(test_expression, m.Name()):
# We are inside a simple check such as "if x".
test_expression = cast(cst.Name, test_expression)
if self._is_optional_type(test_expression):
# We want to replace "if x" with "if x is not None".
replacement_comparison: cst.Comparison = self._gen_comparison_to_none(
variable_name=test_expression.value, operator=cst.IsNot()
)
changes["test"] = replacement_comparison
orelse = original_node.orelse
if orelse is not None and m.matches(orelse, m.If()):
# We want to catch this case upon leaving an `If` node so that we generate an `elif` statement correctly.
# We check if the orelse node was reported, and if so, remove the report and generate a new report on
# the current parent `If` node.
new_reports = []
orelse_report: Optional[CstLintRuleReport] = None
for report in self.context.reports:
if isinstance(report, CstLintRuleReport):
# Check whether the lint rule code matches this lint rule's code so we don't remove another
# lint rule's report.
if report.node is orelse and report.code == self.__class__.__name__:
orelse_report = report
else:
new_reports.append(report)
else:
new_reports.append(report)
if orelse_report is not None:
self.context.reports = new_reports
replacement_orelse = orelse_report.replacement_node
changes["orelse"] = cst.ensure_type(replacement_orelse, cst.CSTNode)
if changes:
self.report(
original_node, replacement=original_node.with_changes(**changes)
)
class ComparisonTest(CSTNodeTest):
@data_provider((
# Simple comparison statements
(
cst.Comparison(
cst.Name("foo"),
(cst.ComparisonTarget(cst.LessThan(), cst.Integer("5")), ),
),
"foo < 5",
),
(
cst.Comparison(
cst.Name("foo"),
(cst.ComparisonTarget(cst.NotEqual(), cst.Integer("5")), ),
),
"foo != 5",
),
(
cst.Comparison(
cst.Name("foo"),
(cst.ComparisonTarget(cst.Is(), cst.Name("True")), )),
"foo is True",
),
(
cst.Comparison(
cst.Name("foo"),
(cst.ComparisonTarget(cst.IsNot(), cst.Name("False")), ),
),
"foo is not False",
),
(
cst.Comparison(
cst.Name("foo"),
(cst.ComparisonTarget(cst.In(), cst.Name("bar")), )),
"foo in bar",
),
(
cst.Comparison(
cst.Name("foo"),
(cst.ComparisonTarget(cst.NotIn(), cst.Name("bar")), ),
),
"foo not in bar",
),
# Comparison with parens
(
cst.Comparison(
lpar=(cst.LeftParen(), ),
left=cst.Name("foo"),
comparisons=(cst.ComparisonTarget(
operator=cst.NotIn(), comparator=cst.Name("bar")), ),
rpar=(cst.RightParen(), ),
),
"(foo not in bar)",
),
(
cst.Comparison(
left=cst.Name("a",
lpar=(cst.LeftParen(), ),
rpar=(cst.RightParen(), )),
comparisons=(
cst.ComparisonTarget(
operator=cst.Is(
whitespace_before=cst.SimpleWhitespace(""),
whitespace_after=cst.SimpleWhitespace(""),
),
comparator=cst.Name("b",
lpar=(cst.LeftParen(), ),
rpar=(cst.RightParen(), )),
),
cst.ComparisonTarget(
operator=cst.Is(
whitespace_before=cst.SimpleWhitespace(""),
whitespace_after=cst.SimpleWhitespace(""),
),
comparator=cst.Name("c",
lpar=(cst.LeftParen(), ),
rpar=(cst.RightParen(), )),
),
),
),
"(a)is(b)is(c)",
),
# Valid expressions that look like they shouldn't parse
(
cst.Comparison(
left=cst.Integer("5"),
comparisons=(cst.ComparisonTarget(
operator=cst.NotIn(
whitespace_before=cst.SimpleWhitespace("")),
comparator=cst.Name("bar"),
), ),
),
"5not in bar",
),
# Validate that spacing works properly
(
cst.Comparison(
lpar=(cst.LeftParen(
whitespace_after=cst.SimpleWhitespace(" ")), ),
left=cst.Name("foo"),
comparisons=(cst.ComparisonTarget(
operator=cst.NotIn(
whitespace_before=cst.SimpleWhitespace(" "),
whitespace_between=cst.SimpleWhitespace(" "),
whitespace_after=cst.SimpleWhitespace(" "),
),
comparator=cst.Name("bar"),
), ),
rpar=(cst.RightParen(
whitespace_before=cst.SimpleWhitespace(" ")), ),
),
"( foo not in bar )",
),
# Do some complex nodes
(
cst.Comparison(
left=cst.Name("baz"),
comparisons=(cst.ComparisonTarget(
operator=cst.Equal(),
comparator=cst.Comparison(
lpar=(cst.LeftParen(), ),
left=cst.Name("foo"),
comparisons=(cst.ComparisonTarget(
operator=cst.NotIn(),
comparator=cst.Name("bar")), ),
rpar=(cst.RightParen(), ),
),
), ),
),
"baz == (foo not in bar)",
CodeRange((1, 0), (1, 23)),
),
(
cst.Comparison(
left=cst.Name("a"),
comparisons=(
cst.ComparisonTarget(operator=cst.GreaterThan(),
comparator=cst.Name("b")),
cst.ComparisonTarget(operator=cst.GreaterThan(),
comparator=cst.Name("c")),
),
),
"a > b > c",
CodeRange((1, 0), (1, 9)),
),
# Is safe to use with word operators if it's leading/trailing children are
(
cst.IfExp(
body=cst.Comparison(
left=cst.Name("a"),
comparisons=(cst.ComparisonTarget(
operator=cst.GreaterThan(),
comparator=cst.Name(
"b",
lpar=(cst.LeftParen(), ),
rpar=(cst.RightParen(), ),
),
), ),
),
test=cst.Comparison(
left=cst.Name("c",
lpar=(cst.LeftParen(), ),
rpar=(cst.RightParen(), )),
comparisons=(cst.ComparisonTarget(
operator=cst.GreaterThan(),
comparator=cst.Name("d")), ),
),
orelse=cst.Name("e"),
whitespace_before_if=cst.SimpleWhitespace(""),
whitespace_after_if=cst.SimpleWhitespace(""),
),
"a > (b)if(c) > d else e",
),
# is safe to use with word operators if entirely surrounded in parenthesis
(
cst.IfExp(
body=cst.Name("a"),
test=cst.Comparison(
left=cst.Name("b"),
comparisons=(cst.ComparisonTarget(
operator=cst.GreaterThan(),
comparator=cst.Name("c")), ),
lpar=(cst.LeftParen(), ),
rpar=(cst.RightParen(), ),
),
orelse=cst.Name("d"),
whitespace_after_if=cst.SimpleWhitespace(""),
whitespace_before_else=cst.SimpleWhitespace(""),
),
"a if(b > c)else d",
),
))
def test_valid(self,
node: cst.CSTNode,
code: str,
position: Optional[CodeRange] = None) -> None:
self.validate_node(node,
code,
parse_expression,
expected_position=position)
@data_provider((
(
lambda: cst.Comparison(
cst.Name("foo"),
(cst.ComparisonTarget(cst.LessThan(), cst.Integer("5")), ),
lpar=(cst.LeftParen(), ),
),
"left paren without right paren",
),
(
lambda: cst.Comparison(
cst.Name("foo"),
(cst.ComparisonTarget(cst.LessThan(), cst.Integer("5")), ),
rpar=(cst.RightParen(), ),
),
"right paren without left paren",
),
(
lambda: cst.Comparison(cst.Name("foo"), ()),
"at least one ComparisonTarget",
),
(
lambda: cst.Comparison(
left=cst.Name("foo"),
comparisons=(cst.ComparisonTarget(
operator=cst.NotIn(whitespace_before=cst.SimpleWhitespace(
"")),
comparator=cst.Name("bar"),
), ),
),
"at least one space around comparison operator",
),
(
lambda: cst.Comparison(
left=cst.Name("foo"),
comparisons=(cst.ComparisonTarget(
operator=cst.NotIn(whitespace_after=cst.SimpleWhitespace(
"")),
comparator=cst.Name("bar"),
), ),
),
"at least one space around comparison operator",
),
# multi-target comparisons
(
lambda: cst.Comparison(
left=cst.Name("a"),
comparisons=(
cst.ComparisonTarget(operator=cst.Is(),
comparator=cst.Name("b")),
cst.ComparisonTarget(
operator=cst.Is(whitespace_before=cst.SimpleWhitespace(
"")),
comparator=cst.Name("c"),
),
),
),
"at least one space around comparison operator",
),
(
lambda: cst.Comparison(
left=cst.Name("a"),
comparisons=(
cst.ComparisonTarget(operator=cst.Is(),
comparator=cst.Name("b")),
cst.ComparisonTarget(
operator=cst.Is(whitespace_after=cst.SimpleWhitespace(
"")),
comparator=cst.Name("c"),
),
),
),
"at least one space around comparison operator",
),
# whitespace around the comparision itself
# a ifb > c else d
(
lambda: cst.IfExp(
body=cst.Name("a"),
test=cst.Comparison(
left=cst.Name("b"),
comparisons=(cst.
ComparisonTarget(operator=cst.GreaterThan(),
comparator=cst.Name("c")), ),
),
orelse=cst.Name("d"),
whitespace_after_if=cst.SimpleWhitespace(""),
),
"Must have at least one space after 'if' keyword.",
),
# a if b > celse d
(
lambda: cst.IfExp(
body=cst.Name("a"),
test=cst.Comparison(
left=cst.Name("b"),
comparisons=(cst.
ComparisonTarget(operator=cst.GreaterThan(),
comparator=cst.Name("c")), ),
),
orelse=cst.Name("d"),
whitespace_before_else=cst.SimpleWhitespace(""),
),
"Must have at least one space before 'else' keyword.",
),
))
def test_invalid(self, get_node: Callable[[], cst.CSTNode],
expected_re: str) -> None:
self.assert_invalid(get_node, expected_re)