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Fix split / rsplit collision #394

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Merged
Otto-AA merged 6 commits into from
Jun 20, 2025
Merged

Fix split / rsplit collision #394

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a32280e
fix(str_swap): Fix simmetric mutations on split rsplit
CHB-0r1s Jun 14, 2025
8e30239
Merge branch 'boxed:main' into main
CHB-0r1s Jun 14, 2025
b7a8c37
fix(str_swap): Remove check of maxsplit value
CHB-0r1s Jun 16, 2025
b585143
Merge remote-tracking branch 'origin/main'
Jun 16, 2025
43e3bfb
fix(str_swap): Add comment
CHB-0r1s Jun 16, 2025
0f34019
fix(str_swap): fix naming
CHB-0r1s Jun 16, 2025
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66 changes: 63 additions & 3 deletions mutmut/node_mutation.py
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Original file line number Diff line number Diff line change
Expand Up @@ -107,13 +107,16 @@ def operator_arg_removal(
("rjust", "ljust"),
("index", "rindex"),
("rindex", "index"),
("split", "rsplit"),
("rsplit", "split"),
("removeprefix", "removesuffix"),
("removesuffix", "removeprefix"),
("partition", "rpartition"),
("rpartition", "partition")
]
]

supported_unsymmetrical_str_methods_swap = [
("split", "rsplit"),
("rsplit", "split")
]

def operator_string_methods_swap(
node: cst.Call
Expand All @@ -125,6 +128,62 @@ def operator_string_methods_swap(
func_name = cst.ensure_type(node.func, cst.Attribute).attr
yield node.with_deep_changes(func_name, value=new_call)

def unsymmetrical_string_methods_swap(
node: cst.Call
) -> Iterable[cst.Call]:
"""Try to handle specific mutations of string, which useful only in specific args combination."""

for old_call, new_call in supported_unsymmetrical_str_methods_swap:
if m.matches(node.func, m.Attribute(value=m.DoNotCare(), attr=m.Name(value=old_call))):
if old_call in {"split", "rsplit"}:
# split() -> split() # not len(node.args)
# rsplit() -> rsplit() # not len(node.args)
# split(" ") -> split(" ") # len(node.args) == 1 & maxsplit not in args
# rsplit(" ") -> rsplit(" ") # len(node.args) == 1 & maxsplit not in args
# split(sep=" ") -> split(sep=" ") # len(node.args) == 1 & maxsplit not in args
# rsplit(sep=" ") -> rsplit(sep=" ") # len(node.args) == 1 & maxsplit not in args
# split(maxsplit=-1) -> split(maxsplit=-1) # maxsplit=-1 in args
# rsplit(maxsplit=-1) -> rsplit(maxsplit=-1) # maxsplit=-1 in args
# split(" ", maxsplit=-1) -> split(" ", maxsplit=-1) # maxsplit=-1 in args
# rsplit(" ", maxsplit=-1) -> rsplit(" ", maxsplit=-1) # maxsplit=-1 in args

# split(maxsplit=1) -> rsplit(maxsplit=1) # maxsplit in args and maxsplit != -1
# rsplit(maxsplit=1) -> split(maxsplit=1) # maxsplit in args and maxsplit != -1

# split(" ", 1) -> rsplit(" ", 1) # len(node.args) == 2 & maxsplit not in args
# rsplit(" ", 1) -> split(" ", 1) # len(node.args) == 2 & maxsplit not in args

# split(" ", maxsplit=1) -> rsplit(" ", maxsplit=1) # maxsplit in args and maxsplit != -1
# rsplit(" ", maxsplit=1) -> split(" ", maxsplit=1) # maxsplit in args and maxsplit != -1
key_args: set[str] = {a.keyword.value for a in node.args if a.keyword}

maxsplit_val = None
for a in node.args:
if a.keyword and a.keyword.value == "maxsplit":
if any([isinstance(child, cst.Minus) for child in a.value.children]):
maxsplit_val = int(a.value.expression.value) * -1
break
if any([isinstance(child, cst.Plus) for child in a.value.children]):
maxsplit_val = int(a.value.expression.value)
break
maxsplit_val = a.value.evaluated_value


if (
not len(node.args) or
(len(node.args) == 1 and "maxsplit" not in key_args) or
("maxsplit" in key_args and maxsplit_val == -1)
):
continue

if (
(len(node.args) == 2 and "maxsplit" not in key_args) or
("maxsplit" in key_args and maxsplit_val != -1)
):
func_name = cst.ensure_type(node.func, cst.Attribute).attr
yield node.with_deep_changes(func_name, value=new_call)



def operator_remove_unary_ops(
node: cst.UnaryOperation
Expand Down Expand Up @@ -239,6 +298,7 @@ def operator_match(node: cst.Match) -> Iterable[cst.CSTNode]:
(cst.Call, operator_dict_arguments),
(cst.Call, operator_arg_removal),
(cst.Call, operator_string_methods_swap),
(cst.Call, unsymmetrical_string_methods_swap),
(cst.Lambda, operator_lambda),
(cst.CSTNode, operator_keywords),
(cst.CSTNode, operator_swap_op),
Expand Down
39 changes: 37 additions & 2 deletions tests/test_mutation.py
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Original file line number Diff line number Diff line change
Expand Up @@ -62,8 +62,43 @@ def mutated_module(source: str) -> str:
]),
('a.index("+")', ['a.rindex("+")', 'a.index("XX+XX")', 'a.index(None)']),
('a.rindex("+")', ['a.index("+")', 'a.rindex("XX+XX")', 'a.rindex(None)']),
('a.split()', 'a.rsplit()'),
('a.rsplit()', 'a.split()'),
('a.split()', []),
('a.rsplit()', []),
('a.split(" ")', ['a.split("XX XX")', 'a.split(None)']),
('a.rsplit(" ")', ['a.rsplit("XX XX")', 'a.rsplit(None)']),
('a.split(sep="")', ['a.split(sep="XXXX")', 'a.split(sep=None)']),
('a.rsplit(sep="")', ['a.rsplit(sep="XXXX")', 'a.rsplit(sep=None)']),
('a.split(maxsplit=-1)', ['a.split(maxsplit=+1)', 'a.split(maxsplit=-2)', 'a.split(maxsplit=None)']),
('a.rsplit(maxsplit=-1)', ['a.rsplit(maxsplit=+1)', 'a.rsplit(maxsplit=-2)', 'a.rsplit(maxsplit=None)']),
('a.split(" ", maxsplit=-1)', [
'a.split(" ", )', 'a.split(" ", maxsplit=+1)', 'a.split(" ", maxsplit=-2)',
'a.split(" ", maxsplit=None)', 'a.split("XX XX", maxsplit=-1)', 'a.split(None, maxsplit=-1)',
'a.split(maxsplit=-1)'
]),
('a.rsplit(" ", maxsplit=-1)', [
'a.rsplit(" ", )', 'a.rsplit(" ", maxsplit=+1)', 'a.rsplit(" ", maxsplit=-2)',
'a.rsplit(" ", maxsplit=None)', 'a.rsplit("XX XX", maxsplit=-1)', 'a.rsplit(None, maxsplit=-1)',
'a.rsplit(maxsplit=-1)'
]),
('a.split(maxsplit=1)', ['a.split(maxsplit=2)', 'a.split(maxsplit=None)', 'a.rsplit(maxsplit=1)']),
('a.rsplit(maxsplit=1)', ['a.rsplit(maxsplit=2)', 'a.rsplit(maxsplit=None)', 'a.split(maxsplit=1)']),
('a.split(" ", 1)', [
'a.rsplit(" ", 1)', 'a.split(" ", )', 'a.split(" ", 2)', 'a.split(" ", None)',
'a.split("XX XX", 1)', 'a.split(1)', 'a.split(None, 1)'
]),
('a.rsplit(" ", 1)', [
'a.rsplit(" ", )', 'a.rsplit(" ", 2)', 'a.rsplit(" ", None)', 'a.rsplit("XX XX", 1)',
'a.rsplit(1)', 'a.rsplit(None, 1)', 'a.split(" ", 1)'
]),
('a.split(" ", maxsplit=1)', [
'a.rsplit(" ", maxsplit=1)', 'a.split(" ", )', 'a.split(" ", maxsplit=2)', 'a.split(" ", maxsplit=None)',
'a.split("XX XX", maxsplit=1)', 'a.split(None, maxsplit=1)', 'a.split(maxsplit=1)'
]),
('a.rsplit(" ", maxsplit=1)', [
'a.rsplit(" ", )', 'a.rsplit(" ", maxsplit=2)', 'a.rsplit(" ", maxsplit=None)',
'a.rsplit("XX XX", maxsplit=1)', 'a.rsplit(None, maxsplit=1)', 'a.rsplit(maxsplit=1)',
'a.split(" ", maxsplit=1)'
]),
('a.removeprefix("+")', ['a.removesuffix("+")', 'a.removeprefix("XX+XX")', 'a.removeprefix(None)']),
('a.removesuffix("+")', ['a.removeprefix("+")', 'a.removesuffix("XX+XX")', 'a.removesuffix(None)']),
('a.partition("++")', ['a.rpartition("++")', 'a.partition("XX++XX")', 'a.partition(None)']),
Expand Down