Use Scala script for targeted releases

Author: rtyley

.github/workflows/generate-targeted-prs.yml

@@ -17,21 +17,20 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v5
-
-      - name: Install xq
-        run: sudo apt install -y xq
-
-      - name: Write a custom scala-steward configuration to target a specific artifact
-        env:
-          GH_TOKEN: ${{ github.token }}
-          TARGET_PR: ${{ inputs.target_pr }}
-        run: ./scripts/write-config-to-target-artefact.sh
-
       - name: Setup Java
         uses: actions/setup-java@v5
         with:
           java-version: "21"
           distribution: "corretto"
+      - uses: coursier/cache-action@4e2615869d13561d626ed48655e1a39e5b192b3c
+      - uses: VirtusLab/scala-cli-setup@77834b5926f3eb70869d8009530c65585f7a039b
+      - name: Write a custom scala-steward configuration to target a specific artifact
+        env:
+          TARGETED_RELEASES_APP_CLIENT_ID: 214238
+          TARGETED_RELEASES_APP_PRIVATE_KEY: ${{ secrets.SCALA_STEWARD_APP_PRIVATE_KEY }}
+        run: |
+          ./scripts/write-config-to-target-artefact.scala ${{ inputs.target_pr }} targeted-scala-steward.conf
+          cat targeted-scala-steward.conf
 
       - name: Execute Scala Steward
         uses: scala-steward-org/scala-steward-action@v2.76.0

scripts/write-config-to-target-artefact.scala

@@ -0,0 +1,111 @@
+#!/usr/bin/env -S scala-cli shebang
+
+//> using scala 3.3.6
+
+//> using dep "com.madgag.play-git-hub::core:10.0.0-PREVIEW.examine-default-branch.2025-10-01T1252.5ed70273"
+
+import cats.*
+import cats.data.*
+import cats.effect.unsafe.implicits.global
+import cats.effect.{ExitCode, IO, IOApp}
+import cats.implicits.*
+import cats.syntax.all.*
+import com.madgag.github.apps.GitHubAppAuth
+import com.madgag.scalagithub
+import com.madgag.scalagithub.GitHub
+import com.madgag.scalagithub.model.{Comment, PullRequest, RepoId}
+import play.api.libs.json.Json.toJson
+import play.api.libs.json.{Json, OWrites}
+import sttp.model.*
+
+import java.nio.file.{Files, Path}
+import scala.collection.immutable.SortedSet
+import scala.concurrent.ExecutionContext.Implicits.global
+
+val gitHubAppAuth: GitHubAppAuth = GitHubAppAuth.fromConfigMap(sys.env, "TARGETED_RELEASES")
+
+case class Config(
+  prId: PullRequest.Id,
+  updates: NonEmptySet[Artifact]
+) {
+  val groupIds: NonEmptySet[String] = updates.map(_.groupId)
+  val versions: NonEmptySet[String] = updates.map(_.version)
+
+  val commitsMessage: String =  "Update ${artifactName} from ${currentVersion} to ${nextVersion}"
+
+  val updatesJson: String = toJson(updates.toSortedSet.toSeq).toString
+
+  val text =
+    s"""
+      |updates.allow = $updatesJson
+      |
+      |updates.allowPreReleases = $updatesJson
+      |
+      |pullRequests.draft = true
+      |commits.message = "$commitsMessage"
+      |pullRequests.grouping = [{
+      |  name = "${prId.slug}",
+      |  title = "Update `${prId.repo.name}` to ${versions.toSortedSet.mkString(", ")}",
+      |  filter = [{"group" = "*"}]
+      |}]
+      |""".stripMargin
+}
+
+case class Artifact(groupId: String, artifactId: String, version: String) {
+  val artifactIdWithoutScalaVersion: String = artifactId.split('_').dropRight(1).mkString("_")
+
+  lazy val withoutScalaVersion: Artifact = copy(artifactId = artifactIdWithoutScalaVersion)
+}
+
+object Artifact {
+  // c96c2303d065496792e7edb379b0e671f57edbb13cecb6b2d94deb22d1a504d4  ./com/gu/panda-hmac-core_3/11.0.0/panda-hmac-core_3-11.0.0.pom
+  def fromSha256PomLine(pomLine: String): Option[Artifact] = {
+    val segments = pomLine.split(' ').last.split('/').drop(1).dropRight(1).reverse.toList
+    segments match {
+      case version :: artifactId :: groupSegments =>
+        Some(Artifact(groupSegments.reverse.mkString("."), artifactId, version))
+      case _ => None
+    }
+  }
+
+  given Order[Artifact] = Order.by(Tuple.fromProductTyped)
+
+  given OWrites[Artifact] = Json.writes
+}
+
+object HelloWorld extends IOApp {
+
+  def run(args: List[String]) = (for {
+    installationAccess <- gitHubAppAuth.accessSoleInstallation()
+    _ <- IO.println(s"Hello, ${installationAccess.installedOnAccount.atLogin}!")
+    prId = PullRequest.Id.from(Uri.unsafeParse(args(0)))
+    outputFile = Path.of(args(1))
+    given GitHub = installationAccess.accountAccess().gitHub
+    pr <- summon[GitHub].getPullRequest(prId).map(_.result)
+    configOpt <- scalaStewardConfigForMostRecentPreviewReleaseOf(pr).value
+    _ <- IO(Files.writeString(outputFile, configOpt.map(_.text).mkString))
+  } yield println(s"Wrote config to ${outputFile.toAbsolutePath}")).as(ExitCode.Success)
+
+  def scalaStewardConfigForMostRecentPreviewReleaseOf(pr: PullRequest)(using GitHub): OptionT[IO, Config] =
+    findLatestPreviewVersionIn(pr).flatMap(version => scalaStewardConfigFor(pr.prId, version))
+
+  def findLatestPreviewVersionIn(pr: PullRequest)(using GitHub): OptionT[IO,String] =
+    OptionT(pr.comments2.list().filter(_.user.login == "gu-scala-library-release[bot]").map(findPreviewVersionIn).unNone.compile.last)
+
+  def findPreviewVersionIn(comment: Comment): Option[String] = comment.body.linesIterator.find(_.contains("-PREVIEW"))
+
+  def tagMessageFor(repoId: RepoId, version: String)(using g: GitHub): IO[String] = for {
+    repo <- g.getRepo(repoId).map(_.result)
+    ref <- repo.refs.get(s"tags/v$version").map(_.result)
+    tag <- repo.tags.get(ref.objectId.name).map(_.result)
+  } yield tag.message
+
+  def artifactsFrom(tagMessage: String): Seq[Artifact] =
+    tagMessage.linesIterator.filter(_.endsWith(".pom")).flatMap(Artifact.fromSha256PomLine).toSeq
+
+  def scalaStewardConfigFor(prId: PullRequest.Id, version: String)(using GitHub): OptionT[IO, Config] = OptionT(for {
+    tagMessage <- tagMessageFor(prId.repo, version)
+  } yield for {
+    artifacts <- NonEmptySet.fromSet(SortedSet.from(artifactsFrom(tagMessage)))
+  } yield Config(prId, artifacts.map(_.withoutScalaVersion)))
+}