With newlines.source = keep linebreaks are not preserved in lists with non-numeric entries

[OndrejSpanel]

Configuration (required)

version = 3.8.1
maxColumn = 120
runner.dialect = scala3
newlines.source = keep

Command-line parameters (required)

When I run scalafmt via CLI like this: scalafmt

Steps

Given code like this:

object Main {
  val a = Set(
    0,
    1, 2, 3,
    4, 5, 6, 7, 8, 9, 10 + 0
  )
  def main(args: Array[String]): Unit = {}
}

Problem

Scalafmt formats code like this:

object Main {
  val a = Set(
    0,
    1,
    2,
    3,
    4,
    5,
    6,
    7,
    8,
    9,
    10 + 0
  )
  def main(args: Array[String]): Unit = {}
}

Expectation

I would like the formatted output to look like this:

object Main {
  val a = Set(
    0,
    1, 2, 3,
    4, 5, 6, 7, 8, 9, 10 + 0
  )
  def main(args: Array[String]): Unit = {}
}

Notes

When all values are numeric literals. it works fine. As soon as any single value is anything else, line-breaks are inserted.

[kitbellew]

this type of formatting is called binpacking, and there's a separate parameter for that. source=keep doesn't guarantee all breaks will be preserved, only when it doesn't contradict other parameters or other constraints.

[OndrejSpanel]

Good to know, but even with binPack.literalArgumentLists = false this is still formatted, as the last value is not a literal.

I have tried following:

binPack.literalArgumentLists = true
binPack.literalsInclude = [".*"]
binPack.literalsIncludeSimpleExpr = true

No matter what I have tried, I am unable to preserve my newlines in such lists. I can use // format: off, but as I prefer this behaviour everywhere in my sources, that does not look very nice.