Description
Describe the bug
Originally I realized that in VSCode the black formatter does not format my code anymore, i.e. the --line-ranges is broken and raises a parser error.
Observation: Difference between black file.py and black --line-range #-# file.py
If there is a def foo(self): ... with ... on the same line black fails to format anything after when used with --line-range.
To Reproduce
For example, take this code:
class Foo:
@overload
def foo(self, *, a: int) -> None: ...
def fox(self):
print('This line is', 'way', 'way', 'way', 'way', 'too long to fit in a single line, so it is split into multiple lines for better readability.')And run it with these arguments:
Fails:
$ black -c --line-ranges 6-7 "class Foo:
@overload
def foo(self, *, a: int) -> None: ...
def fox(self):
print('This line is', 'way', 'way', 'way', 'way', 'too long to fit in a single line, so it is split into multiple lines for better readability.')
"
error: cannot format <string>: Cannot parse for target version Python 3.11: 3:17: @overload def foo(self, *, a: int) -> None: ..Formatting only the ... line changes nothing
$ black -c --line-ranges 1-5 "class Foo:
@overload
def foo(self, *, a: int) -> None: ...
def fox(self):
print('This line is', 'way', 'way', 'way', 'way', 'too long to fit in a single line, so it is split into multiple lines for better readability.')
"
# Trimmed output
@overload
def foo(self, *, a: int) -> None: ...Works:
- Either formatting everything without
--line-rangesworks correctly and does change the long line; also including the seemingly "broken" line seems to work fine. - First putting
...on the next line and then format it is fine:
$black -c "class Foo:
@overload
def foo(self, *, a: int) -> None:
...
def fox(self):
print('This line is', 'way', 'way', 'way', 'way', 'too long to fit in a single line, so it is split into multiple lines for better readability.')
" --line-ranges 7-9In the end, if I format everything ... is again put on the same line and --line-ranges breaks for further editing.
Expected behavior
Parser should not be bothered if ... is on the same line or below anywhere, to have --line-ranges work everywhere independent of style used in above code.
Environment
Ubuntu 22.04
black, 25.1.0 (compiled: no)
Python (CPython) 3.10.16
2025-05-28 09:39:57.081 [info] SUPPORTED black>=22.3.0
FOUND black==25.1.0