Add tlLatestVersion, tlLatestPreReleaseVersion to versioning plugin

kernel/src/main/scala/org/typelevel/sbt/TypelevelKernelPlugin.scala

@@ -20,6 +20,7 @@ import sbt._
 import sbt.plugins.JvmPlugin
 
 import Keys._
+import org.typelevel.sbt.kernel.{GitHelper, V}
 
 object TypelevelKernelPlugin extends AutoPlugin {
 
@@ -37,6 +38,36 @@ object TypelevelKernelPlugin extends AutoPlugin {
           BasicCommands.addAlias(BasicCommands.removeAlias(s, name), name, contents)
         }
       })
+
+    private[sbt] lazy val currentRelease: Def.Initialize[Option[String]] = Def.setting {
+      // some tricky logic here ...
+      // if the latest release is a pre-release (e.g., M or RC)
+      // and there are no stable releases it is bincompatible with,
+      // then for all effective purposes it is the current release
+
+      val release = previousReleases.value match {
+        case head :: tail if head.isPrerelease =>
+          tail
+            .filterNot(_.isPrerelease)
+            .find(head.copy(prerelease = None).mustBeBinCompatWith(_))
+            .orElse(Some(head))
+        case releases => releases.headOption
+      }
+
+      release.map(_.toString)
+    }
+
+    // latest tagged release, including pre-releases
+    private[sbt] lazy val currentPreRelease: Def.Initialize[Option[String]] = Def.setting {
+      previousReleases.value.headOption.map(_.toString)
+    }
+
+    private[sbt] lazy val previousReleases: Def.Initialize[List[V]] = Def.setting {
+      val currentVersion = V(version.value).map(_.copy(prerelease = None))
+      GitHelper.previousReleases(fromHead = true, strict = false).filter { v =>
+        currentVersion.forall(v.copy(prerelease = None) <= _)
+      }
+    }
   }
 
   import autoImport._

site/src/main/scala/org/typelevel/sbt/TypelevelSitePlugin.scala

@@ -26,8 +26,6 @@ import laika.helium.config.ImageLink
 import laika.sbt.LaikaPlugin
 import laika.theme.ThemeProvider
 import mdoc.MdocPlugin
-import org.typelevel.sbt.kernel.GitHelper
-import org.typelevel.sbt.kernel.V
 import org.typelevel.sbt.site._
 import sbt._
 
@@ -250,36 +248,6 @@ object TypelevelSitePlugin extends AutoPlugin {
       )
   )
 
-  private lazy val currentRelease = Def.setting {
-    // some tricky logic here ...
-    // if the latest release is a pre-release (e.g., M or RC)
-    // and there are no stable releases it is bincompatible with,
-    // then for all effective purposes it is the current release
-
-    val release = previousReleases.value match {
-      case head :: tail if head.isPrerelease =>
-        tail
-          .filterNot(_.isPrerelease)
-          .find(head.copy(prerelease = None).mustBeBinCompatWith(_))
-          .orElse(Some(head))
-      case releases => releases.headOption
-    }
-
-    release.map(_.toString)
-  }
-
-  // latest tagged release, including pre-releases
-  private lazy val currentPreRelease = Def.setting {
-    previousReleases.value.headOption.map(_.toString)
-  }
-
-  private lazy val previousReleases = Def.setting {
-    val currentVersion = V(version.value).map(_.copy(prerelease = None))
-    GitHelper.previousReleases(fromHead = true, strict = false).filter { v =>
-      currentVersion.forall(v.copy(prerelease = None) <= _)
-    }
-  }
-
   private def previewTask = Def
     .taskDyn {
       // inlined from https://github.com/planet42/Laika/blob/9022f6f37c9017f7612fa59398f246c8e8c42c3e/sbt/src/main/scala/laika/sbt/Tasks.scala#L192

versioning/src/main/scala/org/typelevel/sbt/TypelevelVersioningPlugin.scala

@@ -25,6 +25,7 @@ import sbt._
 import scala.util.Try
 
 import Keys._
+import org.typelevel.sbt.TypelevelKernelPlugin.autoImport._
 
 object TypelevelVersioningPlugin extends AutoPlugin {
 
@@ -37,6 +38,13 @@ object TypelevelVersioningPlugin extends AutoPlugin {
     lazy val tlUntaggedAreSnapshots =
       settingKey[Boolean](
         "If true, an untagged commit is given a snapshot version, e.g. 0.4-00218f9-SNAPSHOT. If false, it is given a release version, e.g. 0.4-00218f9. (default: true)")
+
+    lazy val tlCurrentRelease =
+      settingKey[Option[String]](
+        "The latest stable released version of your project, e.g. 0.2.0, 3.5.1. If applicable, this will be the version currently being released.")
+
+    lazy val tlCurrentPreRelease = settingKey[Option[String]](
+      "The latest pre-release (e.g. milestone, release candidate) of your project. If applicable, this will be the version currently being released.")
   }
 
   import autoImport._
@@ -123,7 +131,9 @@ object TypelevelVersioningPlugin extends AutoPlugin {
       if (isSnapshot.value) version += "-SNAPSHOT"
 
       version
-    }
+    },
+    tlCurrentRelease := currentRelease.value,
+    tlCurrentPreRelease := currentPreRelease.value
   )
 
   private val Description = """^.*-(\d+)-[a-zA-Z0-9]+$""".r