Black unexpectedly alters comments and one-liner expressions when comments are placed above, when using --preview

[sjdemartini]

Describe the bug

When a comment is placed above a one-liner expression that uses a conditional statement, and --preview mode is on, black changes the comment and one-liner into a parenthesized block, or moves the comment to the end of the expression. The former situation with parentheses happens when the expression is preceded by at least one newline. The latter happens if there is no newline above the comment/expression. Neither of those formatting changes is expected.

This one-liner expression syntax isn't the cleanest, and I would guess black has this behavior for cases where you assign the expression result to a variable, but perhaps this situation should still be left unaltered by black.

To Reproduce

Check this out in the black playground here

Input code:

def foo(wait: bool = True):
    # This full comment and the next one after it will get wrapped into
    # the next one-liner unexpectedly
    
    # even if this comment is separated
    time.sleep(1) if wait else None
    time.sleep(1) if wait else None

    # With newline above
    time.sleep(1) if wait else None
    # Without newline above
    time.sleep(1) if wait else None

Output using latest/main version of black with the --preview argument:

def foo(wait: bool = True):
    (  # This full comment and the next one after it will get wrapped into
        # the next one-liner unexpectedly
        # even if this comment is separated
        time.sleep(1)
        if wait
        else None
    )
    time.sleep(1) if wait else None
    (
        # With newline above
        time.sleep(1)
        if wait
        else None
    )
    time.sleep(1) if wait else None  # Without newline above

Expected behavior: No change to the original code whatsoever. That was Black's behavior prior to the latest version, 23.1.0.

Environment

• Black's version: 23.1.0 or main
• OS and Python version: Python 3.10, Mac

[smackesey]

Here's a related instance. Before:

    tox_command_parts = filter(
        None,
        [
            "tox",
            "-vv",  # extra-verbose
            "-c %s " % tox_file if tox_file else None,
            "-e",
            tox_env,
        ],
    )

After:

    tox_command_parts = filter(
        None,
        [
            "tox",
            "-vv",
            "-c %s " % tox_file if tox_file else None,  # extra-verbose
            "-e",
            tox_env,
        ],
    )

https://black.vercel.app/?version=main&state=_Td6WFoAAATm1rRGAgAhARYAAAB0L-Wj4AEsAKxdAD2IimZxl1N_WmhLJkqqGxy7GTEIPj6BUDFbymKtLrohg4RFtFIh7lTJX-YW74u8QDGqTzO2LRiIA5VrWv_FdeOfDy9N96Ys3SY_Trse64NMwb6iDrZLIsUeYohO6ecE_jfwzK9dqK4F0kYYt72a_z0sYJir2O9le62KLf02o9gnkRgn98pl6VVP7kkaKAJG31i__EgSBa2Bm4pkdCNpGDATo0u4nSZ_GhjjRQAAs4N_w4ZOTVsAAcgBrQIAAAJ0C7-xxGf7AgAAAAAEWVo=

[hauntsaninja]

Seems related to https://github.com/psf/black/pull/2278, cc @JEphron if you're around to take a look

[hauntsaninja]

Got another report of moving comments that traces back to parenthesize_conditional_expressions in https://github.com/psf/black/issues/4042#issuecomment-1859231535

a = "".join(
    (
        "",  # comment
        "" if True else "",
    )
)