Sbt0_13BuildSyntax.scala

package sbt
package internal
package fix

import scalafix.v1._
import scala.meta._

class Sbt0_13BuildSyntax extends SyntacticRule("Sbt0_13BuildSyntax") {
  override def fix(implicit doc: SyntacticDocument): Patch = {
    doc.tree.collect {
      case t: Term.ApplyInfix if t.op.value == "in" && t.lhs.toString != "project" =>
        slashify(t, t.lhs, t.args)
      case t @ Term.Apply(Term.Select(qual, Term.Name("in")), args) if qual.toString != "project" =>
        slashify(t, qual, args)
    }.asPatch
  }

  def slashify(t: Tree, lhs: Term, args: Seq[Term]): Patch =
    args match {
      case List(arg0) =>
        Patch.replaceTree(t, s"($arg0 / $lhs)")
      case List(arg0, arg1) =>
        Patch.replaceTree(t, s"($arg0 / $arg1 / $lhs)")
      case List(arg0, arg1, arg2) =>
        Patch.replaceTree(t, s"($arg0 / $arg1 / $arg2 / $lhs)")
      case _ => Patch.empty
    }
}

The attempt to restrict what forms of in get rewritten didn't work in this example:

-lazy val `play-functional` = crossProject(JVMPlatform, JSPlatform)
-  .crossType(CrossType.Pure)
-  .in(file("play-functional"))
+lazy val `play-functional` = (file("play-functional") / crossProject(JVMPlatform, JSPlatform)
+  .crossType(CrossType.Pure))

no big deal, just something for users to watch out for.

Other than that, the only shortcoming I've noticed is that the rewrite often introduces unnecessary parentheses. I have no idea whether Scalafix offers any way of avoiding that.

This rewrite has been super helpful to me in multiple repos. 🙇

@xuwei-k had an idea of putting parens only at the call site of .value.
https://twitter.com/xuwei_k/status/1361554682276057090

I haven't experimented with that yet.

Seems it's not handling multiple ins correctly. Code like (dependencyClasspath in Compile in emptySbtPlugin) is incorrectly translated to (emptySbtPlugin / dependencyClasspath in Compile)(Compile / dependencyClasspath)