scalafmt rewrites scala 2 syntax into scala 3 in build.sbt file

[mtomko]

Configuration (required)

See https://github.com/mtomko/scalafmt-repro2

Please paste the contents of your .scalafmt.conf file here:

version=3.8.0
runner.dialect = scala3
rewrite.scala3.removeOptionalBraces = true

Command-line parameters (required)

When I run scalafmt via CLI like this: scalafmt

Steps

Given code like this:

ThisBuild / scalaVersion := "3.3.1"

lazy val versions = new {
  val cats = "2.10.0"
}

libraryDependencies += "org.typelevel" %% "cats-core" % versions.cats

Problem

Scalafmt formats code like this:

ThisBuild / scalaVersion := "3.3.1"

lazy val versions = new:
  val cats = "2.10.0"

libraryDependencies += "org.typelevel" %% "cats-core" % versions.cats

Expectation

I would like the formatted output to look like this:

ThisBuild / scalaVersion := "3.3.1"

lazy val versions = new {
  val cats = "2.10.0"
}

libraryDependencies += "org.typelevel" %% "cats-core" % versions.cats

Notes

Briefly discussed on discord: https://discord.com/channels/632642981228314653/632665341864181780/1209538770303721533

[mzuehlke]

This fix doesn't work for files in the project folder.
They still get converted to braceless style which isn't working for sbt

[kitbellew]

This fix doesn't work for files in the project folder. They still get converted to braceless style which isn't working for sbt

can you please be more specific? which files?

[mzuehlke]

This is a minimal repo: https://github.com/mzuehlke/scalafmt-sbt-project-bug

Invoking sbt scalafmtSbt leads to the following diff:

diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 749733c..911726f 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -1,5 +1,4 @@
 import sbt.*

-object Dependencies {
+object Dependencies:
   val cats = "org.typelevel" %% "cats-core" % "2.10.0"
-}

[kitbellew]

@mzuehlke i think you have unrealistic expectations. this is not an sbt file, it's a scala file. if you specify in your configuration that your dialect is scala3, at least for scala files that's what it will be.

[mzuehlke]

Thanks for the clarification. If this is the expected behaviour that's fine. 👍

Maybe an addition to the config would be helpful so that everyone who adds scala3 specific options know that a fileOverride for the "project" folder is needed.