Fold BomModule.Consumer into JavaModule

scalalib/src/mill/scalalib/JavaModule.scala

@@ -321,6 +321,15 @@ trait JavaModule
    */
   def runModuleDeps: Seq[JavaModule] = Seq.empty
 
+  /**
+   *  BOM dependencies of this module.
+   *  This is meant to be overridden to add BOM dependencies.
+   *  To read the value, you should use [[bomModuleDepsChecked]] instead,
+   *  which uses a cached result which is also checked to be free of cycle.
+   *  @see [[bomModuleDepsChecked]]
+   */
+  def bomModuleDeps: Seq[BomModule] = Seq.empty
+
   /**
    * Same as [[moduleDeps]] but checked to not contain cycles.
    * Prefer this over using [[moduleDeps]] directly.
@@ -348,6 +357,16 @@ trait JavaModule
     runModuleDeps
   }
 
+  /**
+   * Same as [[bomModuleDeps]] but checked to not contain cycles.
+   * Prefer this over using [[bomModuleDeps]] directly.
+   */
+  final def bomModuleDepsChecked: Seq[BomModule] = {
+    // trigger initialization to check for cycles
+    recBomModuleDeps
+    bomModuleDeps
+  }
+
   /** Should only be called from [[moduleDepsChecked]] */
   private lazy val recModuleDeps: Seq[JavaModule] =
     ModuleUtils.recursive[JavaModule](
@@ -372,6 +391,14 @@ trait JavaModule
       m => m.runModuleDeps ++ m.moduleDeps
     )
 
+  /** Should only be called from [[bomModuleDepsChecked]] */
+  private lazy val recBomModuleDeps: Seq[BomModule] =
+    ModuleUtils.recursive[BomModule](
+      (millModuleSegments ++ Seq(Segment.Label("bomModuleDeps"))).render,
+      null,
+      mod => if (mod == null) bomModuleDeps else mod.bomModuleDeps
+    )
+
   /** The direct and indirect dependencies of this module */
   def recursiveModuleDeps: Seq[JavaModule] = { recModuleDeps }
 
@@ -482,15 +509,26 @@ trait JavaModule
     )
 
     val internalDependencies =
-      moduleDepsChecked.flatMap { modDep =>
-        Seq(
-          (cs.Configuration.compile, modDep.coursierDependency),
-          (
-            cs.Configuration.runtime,
-            modDep.coursierDependency.withConfiguration(cs.Configuration.runtime)
-          )
+      bomModuleDepsChecked.map { modDep =>
+        val dep = coursier.core.Dependency(
+          coursier.core.Module(
+            coursier.core.Organization("mill-internal"),
+            coursier.core.ModuleName(modDep.millModuleSegments.parts.mkString("-")),
+            Map.empty
+          ),
+          "0+mill-internal"
         )
+        (coursier.core.Configuration.`import`, dep)
       } ++
+        moduleDepsChecked.flatMap { modDep =>
+          Seq(
+            (cs.Configuration.compile, modDep.coursierDependency),
+            (
+              cs.Configuration.runtime,
+              modDep.coursierDependency.withConfiguration(cs.Configuration.runtime)
+            )
+          )
+        } ++
         compileModuleDepsChecked.map { modDep =>
           (cs.Configuration.provided, modDep.coursierDependency)
         } ++
@@ -561,7 +599,8 @@ trait JavaModule
     val projects = Seq(coursierProject()) ++
       T.traverse(compileModuleDepsChecked)(_.transitiveCoursierProjects)().flatten ++
       T.traverse(moduleDepsChecked)(_.transitiveCoursierProjects)().flatten ++
-      T.traverse(runModuleDepsChecked)(_.transitiveCoursierProjects)().flatten
+      T.traverse(runModuleDepsChecked)(_.transitiveCoursierProjects)().flatten ++
+      T.traverse(bomModuleDepsChecked)(_.transitiveCoursierProjects)().flatten
     projects.distinct
   }
 
@@ -1475,3 +1514,29 @@ object JavaModule {
       Nil
   }
 }
+
+trait BomModule extends JavaModule {
+  def compile: T[CompilationResult] = Task {
+    val sources = allSourceFiles()
+    if (sources.nonEmpty)
+      throw new Exception(s"A BomModule cannot have sources")
+    CompilationResult(T.dest / "zinc", PathRef(T.dest / "classes"))
+  }
+
+  def resources: T[Seq[PathRef]] = Task {
+    val value = super.resources()
+    if (value.nonEmpty)
+      throw new Exception(s"A BomModule cannot have ressources")
+    Seq.empty[PathRef]
+  }
+
+  def jar: T[PathRef] = Task {
+    (throw new Exception(s"A BomModule doesn't have a JAR")): PathRef
+  }
+  def docJar: T[PathRef] = Task {
+    (throw new Exception(s"A BomModule doesn't have a doc JAR")): PathRef
+  }
+  def sourceJar: T[PathRef] = Task {
+    (throw new Exception(s"A BomModule doesn't have a source JAR")): PathRef
+  }
+}

scalalib/src/mill/scalalib/PublishModule.scala

@@ -31,7 +31,11 @@ trait PublishModule extends JavaModule { outer =>
   /**
    * The packaging type. See [[PackagingType]] for specially handled values.
    */
-  def pomPackagingType: String = PackagingType.Jar
+  def pomPackagingType: String =
+    this match {
+      case _: BomModule => PackagingType.Pom
+      case _ => PackagingType.Jar
+    }
 
   /**
    * POM parent project.
@@ -171,7 +175,13 @@ trait PublishModule extends JavaModule { outer =>
    * BOM dependency to specify in the POM
    */
   def publishXmlBomDeps: Task[Agg[Dependency]] = Task.Anon {
-    bomIvyDeps().map(resolvePublishDependency.apply().apply(_))
+    val fromBomMods = T.traverse(
+      bomModuleDepsChecked.collect { case p: PublishModule => p }
+    )(_.artifactMetadata)().map { a =>
+      Dependency(a, Scope.Import)
+    }
+    Agg(fromBomMods: _*) ++
+      bomIvyDeps().map(resolvePublishDependency.apply().apply(_))
   }
 
   /**

scalalib/test/src/mill/scalalib/BomTests.scala

@@ -405,7 +405,7 @@ object BomTests extends TestSuite {
           ivy"com.lihaoyi:os-lib_2.13:0.11.3"
         )
 
-        object bomUser extends BomModule.Consumer with TestPublishModule {
+        object bomUser extends JavaModule with TestPublishModule {
           def bomModuleDeps = Seq(depMgmtBomMod)
           def ivyDeps = Agg(
             ivy"com.lihaoyi:os-lib_2.13"
@@ -419,7 +419,7 @@ object BomTests extends TestSuite {
           ivy"com.lihaoyi::os-lib:0.11.3"
         )
 
-        object bomUser extends ScalaModule with BomModule.Consumer with TestPublishModule {
+        object bomUser extends ScalaModule with TestPublishModule {
           def scalaVersion = "2.13.15"
           def bomModuleDeps = Seq(scalaDepMgmtBomMod)
           def ivyDeps = Agg(
@@ -436,7 +436,7 @@ object BomTests extends TestSuite {
           ivy"com.lihaoyi:os-lib_2.13:0.11.3"
         )
 
-        object bomUser extends BomModule.Consumer with TestPublishModule {
+        object bomUser extends JavaModule with TestPublishModule {
           def bomModuleDeps = Seq(bomWithBom)
           def ivyDeps = Agg(
             ivy"com.lihaoyi:os-lib_2.13",
@@ -454,7 +454,7 @@ object BomTests extends TestSuite {
           ivy"com.google.protobuf:protobuf-java:4.28.0"
         )
 
-        object bomUser extends BomModule.Consumer with TestPublishModule {
+        object bomUser extends JavaModule with TestPublishModule {
           def bomModuleDeps = Seq(bomWithBomOverride)
           def ivyDeps = Agg(
             ivy"com.lihaoyi:os-lib_2.13",
@@ -480,7 +480,7 @@ object BomTests extends TestSuite {
             ivy"com.fasterxml.jackson.core:jackson-core:2.18.2"
           )
 
-          object bomUser extends BomModule.Consumer with TestPublishModule {
+          object bomUser extends JavaModule with TestPublishModule {
             def bomModuleDeps = Seq(simpleOverrides)
             def ivyDeps = Agg(
               ivy"com.fasterxml.jackson.core:jackson-core",
@@ -498,7 +498,7 @@ object BomTests extends TestSuite {
             ivy"com.google.protobuf:protobuf-java:4.28.2"
           )
 
-          object bomUser extends BomModule.Consumer with TestPublishModule {
+          object bomUser extends JavaModule with TestPublishModule {
             def bomModuleDeps = Seq(crossedOverrides)
             def ivyDeps = Agg(
               ivy"com.fasterxml.jackson.core:jackson-core",