Formatter: Expands function call after multi-line string

[konstin]

"""
{}
""".format("hi")

should be formatted as

"""
{}
""".format(
    "hi"
)

This depends on the string content, e.g.

"""{}""".format("hi")

does not get expanded.

[charliermarsh]

It looks like this no longer happens in Black's preview style: https://black.vercel.app/?version=main&state=_Td6WFoAAATm1rRGAgAhARYAAAB0L-Wj4ACHAFhdAD2IimZxl1N_Wk8Jgdzhwf57J25o-MMyJFDdKTbHVMsgIS4qWrqO3MV-q3-8HoAKJvbhIFbv_2jUfXQyafZeaz7n_OCmk3vdd7F3rCF3dZvDEseZ-a6DkyQAYnRsQVfRpAwAAXSIAQAAADwHzGqxxGf7AgAAAAAEWVo=

[charliermarsh]

Okay, I think it's psf/black#256 and psf/black#1879. Closing as I think this is reasonable given it's in preview.

[charliermarsh]

However, there's another behavior implemented in the linked PRs that we don't have: #6581.