Support Scala 3

build.sbt

@@ -1,15 +1,17 @@
 import ReleaseTransformations._
+import Dependencies._
 
 lazy val baseSettings = Seq(
   scalaVersion := "2.13.10",
-  crossScalaVersions := Seq(scalaVersion.value),
+  crossScalaVersions := Seq(scalaVersion.value, "3.2.1"),
   organization := "com.madgag.scala-git",
   scmInfo := Some(ScmInfo(
     url("https://github.com/rtyley/scala-git"),
     "scm:git:[email protected]:rtyley/scala-git.git"
   )),
   licenses := Seq("Apache-2.0" -> url("http://www.apache.org/licenses/LICENSE-2.0")),
-  scalacOptions ++= Seq("-deprecation", "-unchecked")
+  scalacOptions ++= Seq("-deprecation", "-unchecked"),
+  libraryDependencies ++= Seq(madgagCompress % Test, scalatest % Test)
 )
 
 lazy val `scala-git` = project.settings(baseSettings: _*).dependsOn(`scala-git-test` % Test)

project/Dependencies.scala

@@ -2,12 +2,12 @@ import sbt._
 
 object Dependencies {
 
-  val jgit = "org.eclipse.jgit" % "org.eclipse.jgit" % "6.4.0.202211300538-r"
+  val jgit = "org.eclipse.jgit" % "org.eclipse.jgit" % "6.7.0.202309050840-r"
 
-  val scalatest = "org.scalatest" %% "scalatest" % "3.2.14"
+  val scalatest = "org.scalatest" %% "scalatest" % "3.2.15"
 
   val madgagCompress = "com.madgag" % "util-compress" % "1.35"
 
-  val guava = Seq("com.google.guava" % "guava" % "31.1-jre", "com.google.code.findbugs" % "jsr305" % "2.0.1")
+  val guava = Seq("com.google.guava" % "guava" % "31.1-jre", "com.google.code.findbugs" % "jsr305" % "3.0.2")
 
 }

project/build.properties

@@ -1 +1 @@
-sbt.version=1.8.0
+sbt.version=1.9.7

project/plugins.sbt

@@ -1,5 +1,5 @@
 addSbtPlugin("com.github.sbt" % "sbt-release" % "1.1.0")
 
-addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.1.2")
+addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.2.1")
 
-addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "3.9.15")
+addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "3.9.21")

scala-git/src/main/scala/com/madgag/diff/MapDiff.scala

@@ -1,6 +1,6 @@
 package com.madgag.diff
 
-import com.madgag.scala.collection.decorators.MapDecorator
+import com.madgag.scala.collection.decorators._
 
 object MapDiff {
   def apply[K,V](before: Map[K,V], after: Map[K,V]): MapDiff[K,V] =
@@ -12,7 +12,7 @@ case class MapDiff[K, V](beforeAndAfter: Map[BeforeAndAfter, Map[K,V]]) {
   lazy val commonElements: Set[K] = beforeAndAfter.values.map(_.keySet).reduce(_ intersect _)
 
   lazy val only: Map[BeforeAndAfter, Map[K,V]] =
-    beforeAndAfter.mapV(_.view.filterKeys(!commonElements(_)).toMap)
+    beforeAndAfter.mapV(_.view.filterKeys(!commonElements(_)).toMap).toMap
 
   lazy val (unchanged, changed) =
     commonElements.partition(k => beforeAndAfter(Before)(k) == beforeAndAfter(After)(k))

scala-git/src/main/scala/com/madgag/git/package.scala

@@ -94,7 +94,7 @@ package object git {
       (revWalk, revWalk.getObjectReader)
     }
 
-    def nonSymbolicRefs = repo.getAllRefs.asScala.values.filterNot(_.isSymbolic)
+    def nonSymbolicRefs = repo.getRefDatabase.getRefs.asScala.filterNot(_.isSymbolic).toSeq
 
   }
 
@@ -172,7 +172,7 @@ package object git {
   implicit class RichRevObject(revObject: RevObject) {
     lazy val typeString = Constants.typeString(revObject.getType)
 
-    def toTree(implicit revWalk: RevWalk): Option[RevTree] = treeOrBlobPointedToBy(revObject).right.toOption
+    def toTree(implicit revWalk: RevWalk): Option[RevTree] = treeOrBlobPointedToBy(revObject).toOption
   }
 
   val FileModeNames = Map(