string_processing: Extra parentheses added even when string isn't split #3466
Description
Describe the bug
With preview style, a long f-string where the only spaces are in the expression bit has parentheses added even though it isn't split over lines. For example:
f(
f'longstringwithnospacesinthestringbitbutwithspacesintheformattyfstringbithere{ 1 }',
)becomes
f(
(
f"longstringwithnospacesinthestringbitbutwithspacesintheformattyfstringbithere{ 1 }"
),
)I would instead expect it not to have changed. See on black playground
I noticed it also seems to occur with normal strings where the split is very near the start or end
f(
"l ongstringwithnospacesinthestringbitbutwithspacesintheformattyfstringbitherelollol",
)becomes
f(
(
"l ongstringwithnospacesinthestringbitbutwithspacesintheformattyfstringbitherelollol"
),
)See on black playground
Version
Black 23.1a1, with --preview