format produces sematically incorrect output when lambda body contains implicit string concatenation #23851
Description
Summary
When a lambda contains a implicitly concatenated string where the string is a format string that takes lambda's param as the format arg, if the line is too long, ruff format will split the string across multiple lines without parenthesizing the string, turning the string into 2 separate strings, breaking the format string.
# Input
foo = lambda x: 'hello this is a really long string that then get concatenated ' 'with another string that prints {x!r}'.format(x=x)
# Ruff
foo = lambda x: "hello this is a really long string that then get concatenated "
"with another string that prints {x!r}".format(x=x)
# ^ NameError: name 'x' is not defined
# Black
foo = (
lambda x: "hello this is a really long string that then get concatenated "
"with another string that prints {x!r}".format(x=x)
)https://play.ruff.rs/160f41fc-c9ae-4422-8024-327f48bc2652
I was able to bisect the bug and found the regression begins at b534607
Friendly ping @dylwil3
Version
ruff 0.15.5+172 (fd9568a 2026-03-09)