Extract dependencies from Gradle Version Catalogs

This adds partial support for Gradle builds that use a [version
catalog](https://docs.gradle.org/current/userguide/version_catalogs.html)
(i.e. a `gradle/libs.versions.toml` file). Dependencies are extracted
from the version catalog just by parsing the `libs.versions.toml` file.
Since the version catalog only contains libraries and no resolvers, the
default resolver is used for the `Scope` of these libraries. This is
one reason why this Gradle support is only partial. The other is that
additional dependencies and plugins that are defined in other Gradle
build files are also ignored.

Closes: #3534

Author: fthomas

build.sbt

@@ -149,6 +149,7 @@ lazy val core = myCrossProject("core")
       Dependencies.monocleCore,
       Dependencies.refined,
       Dependencies.scalacacheCaffeine,
+      Dependencies.tomlj,
       Dependencies.logbackClassic % Runtime,
       Dependencies.catsLaws % Test,
       Dependencies.circeLiteral % Test,

docs/repo-specific-configuration.md

@@ -130,7 +130,7 @@ updates.allowPreReleases  = [ { groupId = "com.example", artifactId="foo" } ]
 updates.limit = 5
 
 # The extensions of files that should be updated.
-# Default: [".mill",".sbt",".sbt.shared",".sc",".scala",".scalafmt.conf",".sdkmanrc",".yml","build.properties","mill-version","pom.xml"]
+# Default: [".mill",".sbt",".sbt.shared",".sc",".scala",".scalafmt.conf",".sdkmanrc",".yml","build.properties","libs.versions.toml","mill-version","pom.xml"]
 updates.fileExtensions = [".scala", ".sbt", ".sbt.shared", ".sc", ".yml", ".md", ".markdown", ".txt"]
 
 # If "on-conflicts", Scala Steward will update the PR it created to resolve conflicts as

modules/core/src/main/scala/org/scalasteward/core/application/Context.scala

@@ -25,6 +25,7 @@ import org.http4s.client.Client
 import org.http4s.headers.`User-Agent`
 import org.scalasteward.core.application.Config.ForgeCfg
 import org.scalasteward.core.buildtool.BuildToolDispatcher
+import org.scalasteward.core.buildtool.gradle.GradleAlg
 import org.scalasteward.core.buildtool.maven.MavenAlg
 import org.scalasteward.core.buildtool.mill.MillAlg
 import org.scalasteward.core.buildtool.sbt.SbtAlg
@@ -61,6 +62,7 @@ final class Context[F[_]](implicit
     val filterAlg: FilterAlg[F],
     val forgeRepoAlg: ForgeRepoAlg[F],
     val gitAlg: GitAlg[F],
+    val gradleAlg: GradleAlg[F],
     val hookExecutor: HookExecutor[F],
     val httpJsonClient: HttpJsonClient[F],
     val logger: Logger[F],
@@ -176,6 +178,7 @@ object Context {
       implicit val versionsCache: VersionsCache[F] =
         new VersionsCache[F](config.cacheTtl, versionsStore)
       implicit val updateAlg: UpdateAlg[F] = new UpdateAlg[F]
+      implicit val gradleAlg: GradleAlg[F] = new GradleAlg[F](config.defaultResolver)
       implicit val mavenAlg: MavenAlg[F] = new MavenAlg[F](config)
       implicit val sbtAlg: SbtAlg[F] = new SbtAlg[F](config)
       implicit val scalaCliAlg: ScalaCliAlg[F] = new ScalaCliAlg[F]

modules/core/src/main/scala/org/scalasteward/core/buildtool/BuildToolDispatcher.scala

@@ -18,6 +18,7 @@ package org.scalasteward.core.buildtool
 
 import cats.Monad
 import cats.syntax.all.*
+import org.scalasteward.core.buildtool.gradle.GradleAlg
 import org.scalasteward.core.buildtool.maven.MavenAlg
 import org.scalasteward.core.buildtool.mill.MillAlg
 import org.scalasteward.core.buildtool.sbt.SbtAlg
@@ -29,6 +30,7 @@ import org.scalasteward.core.scalafmt.ScalafmtAlg
 import org.typelevel.log4cats.Logger
 
 final class BuildToolDispatcher[F[_]](implicit
+    gradleAlg: GradleAlg[F],
     logger: Logger[F],
     mavenAlg: MavenAlg[F],
     millAlg: MillAlg[F],
@@ -53,7 +55,7 @@ final class BuildToolDispatcher[F[_]](implicit
       buildTools.traverse_(_.runMigration(buildRoot, migration))
     })
 
-  private val allBuildTools = List(mavenAlg, millAlg, sbtAlg, scalaCliAlg)
+  private val allBuildTools = List(gradleAlg, mavenAlg, millAlg, sbtAlg, scalaCliAlg)
   private val fallbackBuildTool = List(sbtAlg)
 
   private def findBuildTools(buildRoot: BuildRoot): F[(BuildRoot, List[BuildToolAlg[F]])] =

modules/core/src/main/scala/org/scalasteward/core/buildtool/gradle/GradleAlg.scala

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2018-2025 Scala Steward contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.scalasteward.core.buildtool.gradle
+
+import better.files.File
+import cats.Monad
+import cats.syntax.all.*
+import org.scalasteward.core.buildtool.{BuildRoot, BuildToolAlg}
+import org.scalasteward.core.data.Scope.Dependencies
+import org.scalasteward.core.data.{Resolver, Scope}
+import org.scalasteward.core.io.{FileAlg, WorkspaceAlg}
+import org.typelevel.log4cats.Logger
+
+final class GradleAlg[F[_]](defaultResolver: Resolver)(implicit
+    fileAlg: FileAlg[F],
+    override protected val logger: Logger[F],
+    workspaceAlg: WorkspaceAlg[F],
+    F: Monad[F]
+) extends BuildToolAlg[F] {
+  override def name: String = "Gradle"
+
+  override def containsBuild(buildRoot: BuildRoot): F[Boolean] =
+    libsVersionsToml(buildRoot).flatMap(fileAlg.isRegularFile)
+
+  override def getDependencies(buildRoot: BuildRoot): F[List[Dependencies]] =
+    libsVersionsToml(buildRoot)
+      .flatMap(fileAlg.readFile)
+      .map(_.getOrElse(""))
+      .map(gradleParser.parseDependenciesAndPlugins)
+      .map { case (dependencies, plugins) =>
+        val ds = Option.when(dependencies.nonEmpty)(Scope(dependencies, List(defaultResolver)))
+        val ps = Option.when(plugins.nonEmpty)(Scope(plugins, List(pluginsResolver)))
+        ds.toList ++ ps.toList
+      }
+
+  private def libsVersionsToml(buildRoot: BuildRoot): F[File] =
+    workspaceAlg.buildRootDir(buildRoot).map(_ / "gradle" / libsVersionsTomlName)
+}

modules/core/src/main/scala/org/scalasteward/core/buildtool/gradle/gradleParser.scala

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2018-2025 Scala Steward contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.scalasteward.core.buildtool.gradle
+
+import cats.implicits.*
+import org.scalasteward.core.data.{ArtifactId, Dependency, GroupId, Version}
+import org.tomlj.{Toml, TomlTable}
+import scala.jdk.CollectionConverters.*
+
+object gradleParser {
+  def parseDependenciesAndPlugins(input: String): (List[Dependency], List[Dependency]) = {
+    val parsed = Toml.parse(input)
+    val versionsTable = getTableSafe(parsed, "versions")
+    val librariesTable = getTableSafe(parsed, "libraries")
+    val pluginsTable = getTableSafe(parsed, "plugins")
+
+    val dependencies = collectEntries(librariesTable, parseDependency(_, versionsTable))
+    val plugins = collectEntries(pluginsTable, parsePlugin(_, versionsTable))
+
+    (dependencies, plugins)
+  }
+
+  private def collectEntries[A: Ordering](table: TomlTable, f: TomlTable => Option[A]): List[A] = {
+    val aSet = table.entrySet().asScala.map(_.getValue).flatMap {
+      case t: TomlTable => f(t)
+      case _            => None
+    }
+    aSet.toList.sorted
+  }
+
+  private def parseDependency(lib: TomlTable, versions: TomlTable): Option[Dependency] =
+    for {
+      case (groupId, artifactId) <- parseModuleObj(lib).orElse(parseModuleString(lib))
+      version <- parseVersion(lib, versions)
+    } yield Dependency(groupId, artifactId, version)
+
+  private def parseModuleObj(lib: TomlTable): Option[(GroupId, ArtifactId)] =
+    for {
+      groupId <- getStringSafe(lib, "group").map(GroupId(_))
+      artifactId <- getStringSafe(lib, "name").map(ArtifactId(_))
+    } yield (groupId, artifactId)
+
+  private def parseModuleString(lib: TomlTable): Option[(GroupId, ArtifactId)] =
+    getStringSafe(lib, "module").flatMap {
+      _.split(':') match {
+        case Array(g, a) => Some((GroupId(g), ArtifactId(a)))
+        case _           => None
+      }
+    }
+
+  private def parsePlugin(plugin: TomlTable, versions: TomlTable): Option[Dependency] =
+    for {
+      id <- getStringSafe(plugin, "id")
+      groupId = GroupId(id)
+      artifactId = ArtifactId(s"$id.gradle.plugin")
+      version <- parseVersion(plugin, versions)
+    } yield Dependency(groupId, artifactId, version)
+
+  private def parseVersion(table: TomlTable, versions: TomlTable): Option[Version] = {
+    def versionString = getStringSafe(table, "version")
+    def versionRef = getStringSafe(table, "version.ref").flatMap(getStringSafe(versions, _))
+    versionString.orElse(versionRef).map(Version.apply)
+  }
+
+  private def getTableSafe(table: TomlTable, key: String): TomlTable =
+    Option
+      .when(table.contains(key) && table.isTable(key))(table.getTableOrEmpty(key))
+      .getOrElse(emptyTable)
+
+  private val emptyTable: TomlTable = Toml.parse("")
+
+  private def getStringSafe(table: TomlTable, key: String): Option[String] =
+    Option.when(table.contains(key) && table.isString(key))(table.getString(key))
+}

modules/core/src/main/scala/org/scalasteward/core/buildtool/gradle/package.scala

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2018-2025 Scala Steward contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.scalasteward.core.buildtool
+
+import org.scalasteward.core.data.Resolver
+
+package object gradle {
+  val libsVersionsTomlName = "libs.versions.toml"
+
+  val pluginsResolver: Resolver.MavenRepository =
+    Resolver.MavenRepository("gradle-plugins", "https://plugins.gradle.org/m2/", None, None)
+}

modules/core/src/main/scala/org/scalasteward/core/repoconfig/UpdatesConfig.scala

@@ -22,11 +22,9 @@ import eu.timepit.refined.types.numeric.NonNegInt
 import io.circe.generic.semiauto.deriveCodec
 import io.circe.refined.*
 import io.circe.{Codec, Decoder}
-import org.scalasteward.core.buildtool.maven.pomXmlName
-import org.scalasteward.core.buildtool.mill.MillAlg
-import org.scalasteward.core.buildtool.sbt.buildPropertiesName
+import org.scalasteward.core.buildtool.{gradle, maven, mill, sbt}
 import org.scalasteward.core.data.{GroupId, Update}
-import org.scalasteward.core.scalafmt.scalafmtConfName
+import org.scalasteward.core.scalafmt
 import org.scalasteward.core.update.FilterAlg.{
   FilterResult,
   IgnoredByConfig,
@@ -106,16 +104,17 @@ object UpdatesConfig {
   val defaultFileExtensions: Set[String] =
     Set(
       ".mill",
-      MillAlg.millVersionName,
       ".sbt",
       ".sbt.shared",
       ".sc",
       ".scala",
-      scalafmtConfName,
       ".sdkmanrc",
       ".yml",
-      buildPropertiesName,
-      pomXmlName
+      gradle.libsVersionsTomlName,
+      maven.pomXmlName,
+      mill.MillAlg.millVersionName,
+      sbt.buildPropertiesName,
+      scalafmt.scalafmtConfName
     )
 
   val defaultLimit: Option[NonNegInt] = None

modules/core/src/test/scala/org/scalasteward/core/buildtool/BuildToolDispatcherTest.scala

@@ -41,12 +41,14 @@ class BuildToolDispatcherTest extends FunSuite {
     }
 
     val expectedState = initial.copy(trace =
-      Cmd("test", "-f", s"$repoDir/pom.xml") +:
+      Cmd("test", "-f", s"$repoDir/gradle/libs.versions.toml") +:
+        Cmd("test", "-f", s"$repoDir/pom.xml") +:
         Cmd("test", "-f", s"$repoDir/build.sc") +:
         Cmd("test", "-f", s"$repoDir/build.mill") +:
         Cmd("test", "-f", s"$repoDir/build.mill.scala") +:
         Cmd("test", "-f", s"$repoDir/build.sbt") +:
         allGreps ++:
+        Cmd("test", "-f", s"$repoDir/mvn-build/gradle/libs.versions.toml") +:
         Cmd("test", "-f", s"$repoDir/mvn-build/pom.xml") +:
         Cmd("test", "-f", s"$repoDir/mvn-build/build.sc") +:
         Cmd("test", "-f", s"$repoDir/mvn-build/build.mill") +:

modules/core/src/test/scala/org/scalasteward/core/buildtool/gradle/GradleAlgTest.scala

@@ -0,0 +1,33 @@
+package org.scalasteward.core.buildtool.gradle
+
+import munit.CatsEffectSuite
+import org.scalasteward.core.TestSyntax.*
+import org.scalasteward.core.buildtool.BuildRoot
+import org.scalasteward.core.data.{Repo, Scope}
+import org.scalasteward.core.mock.MockContext.context.*
+import org.scalasteward.core.mock.{MockEffOps, MockState}
+
+class GradleAlgTest extends CatsEffectSuite {
+  test("getDependencies") {
+    val repo = Repo("gradle-alg", "test-getDependencies")
+    val buildRoot = BuildRoot(repo, ".")
+    val buildRootDir = workspaceAlg.buildRootDir(buildRoot).unsafeRunSync()
+
+    val initial = MockState.empty.addFiles(
+      buildRootDir / "gradle" / libsVersionsTomlName ->
+        """|[libraries]
+           |tomlj = { group = "org.tomlj", name = "tomlj", version = "1.1.1" }
+           |[plugins]
+           |kotlin-jvm = { id = "org.jetbrains.kotlin.jvm", version = "2.1.20-Beta1" }
+           |""".stripMargin
+    )
+    val obtained = initial.flatMap(gradleAlg.getDependencies(buildRoot).runA)
+    val kotlinJvm =
+      "org.jetbrains.kotlin.jvm".g % "org.jetbrains.kotlin.jvm.gradle.plugin".a % "2.1.20-Beta1"
+    val expected = List(
+      List("org.tomlj".g % "tomlj".a % "1.1.1").withMavenCentral,
+      Scope(List(kotlinJvm), List(pluginsResolver))
+    )
+    assertIO(obtained, expected)
+  }
+}