Incorrect line breaking with expressions that use parenthesis

[bruceleban]

Describe the bug

Black does not correctly break lines in some cases. In the first two of these examples below it incorrectly puts foo( at the end of a line instead of breaking at the or binary operator as it should. In the other three cases, where I've added a third or clause, it breaks correctly.

This code

if (
    foo(1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
    or foo(1, 2, 3, 4, 5, 6)
):
    pass

is incorrectly formatted as

if foo(1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9) or foo(
    1, 2, 3, 4, 5, 6
):
    pass

To Reproduce

Using https://black.vercel.app/ enter this code:

# These first two are incorrectly formatted.
if (
    foo(1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
    or foo(1, 2, 3, 4, 5, 6)
):
    pass
if (
    foo(1, 2, 3, 4, 5, 6)
    or foo(1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
):
    pass
# These next three are correctly formatted.
if (
    foo(1)
    or foo(1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
    or foo(1, 2, 3, 4, 5, 6)
):
    pass
if (
    foo(1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
    or foo(1, 2, 3, 4, 5, 6)
    or foo(1)
):
    pass
if (
    foo(1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
    or foo(1)
    or foo(1, 2, 3, 4, 5, 6)
):
    pass
# These next two examples show it is not simply a line length issue.
# It removes the outer parentheses because it all fits on one line (as documented).
if foo(1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5) or foo(1) or foo(1, 2, 3, 4, 5, 6):
    pass
# This case is three characters longer and no longer fits on one line
# so it breaks it -- in this case correctly.
if (
    foo(1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6)
    or foo(1)
    or foo(1, 2, 3, 4, 5, 6)
):
    pass

Expected behavior

All of these should follow PEP 8 and break before the or operator.

Environment (please complete the following information):

• https://black.vercel.app/ is currently running v21.9b0
• (Also repros for me locally.)

Does this bug also happen on main?

Yes. main == @06ccb8 at the time I submitted this.

[felix-hilden]

Hi! This is known and discussed in length in #1811 and #2156, so I'll close this as a duplicate.