Let prepareOffline accept a hint parameter

This should support more fine-control in inheriting modules.

Also, fetch only essential dependency in Java and Scala module,
and keep the full fetch behint hints: all, source, ...

scalalib/src/JavaModule.scala

@@ -772,13 +772,32 @@ trait JavaModule
 
   def forkWorkingDir: Target[Path] = T { os.pwd }
 
+  /**
+   * @param hint "all" - fetch all dependencies,
+   *             "source" | "sources" - fetch source dependencies
+   */
   @nowarn("msg=pure expression does nothing")
-  override def prepareOffline(): Command[Unit] = T.command {
-    super.prepareOffline()()
-    resolvedIvyDeps()
-    zincWorker.prepareOffline()()
-    resolvedRunIvyDeps()
-    ()
+  override def prepareOffline(hint: String*): Command[Unit] = {
+    val withSources = hint.contains("all") || hint.contains("source") || hint.contains("sources")
+    val tasks = Seq(
+      if (withSources) Seq(
+        resolveDeps(
+          T.task {
+            transitiveCompileIvyDeps() ++ transitiveIvyDeps()
+          },
+          sources = true
+        )
+      )
+      else Seq()
+    ).flatten
+    T.command {
+      super.prepareOffline(hint: _*)()
+      resolvedIvyDeps()
+      zincWorker.prepareOffline()()
+      resolvedRunIvyDeps()
+      T.sequence(tasks)()
+      ()
+    }
   }
 
   @internal

scalalib/src/ScalaModule.scala

@@ -2,26 +2,17 @@ package mill
 package scalalib
 
 import scala.annotation.nowarn
+
 import mill.define.{Command, Sources, Target, Task}
 import mill.api.{DummyInputStream, PathRef, Result, internal}
 import mill.modules.Jvm
 import mill.modules.Jvm.createJar
-import mill.scalalib.api.Util.{
-  isDotty,
-  isDottyOrScala3,
-  isScala3,
-  isScala3Milestone,
-  scalaBinaryVersion
-}
 import Lib._
 import ch.epfl.scala.bsp4j.{BuildTargetDataKind, ScalaBuildTarget, ScalaPlatform}
 import mill.api.Loose.Agg
-import mill.define.Segment.Label
 import mill.eval.{Evaluator, EvaluatorPathsResolver}
-import mill.scalalib.api.CompilationResult
+import mill.scalalib.api.{CompilationResult, ZincWorkerUtil}
 import mill.scalalib.bsp.{BspBuildTarget, BspModule}
-import os.SubPath
-
 import scala.jdk.CollectionConverters._
 
 /**
@@ -46,7 +37,7 @@ trait ScalaModule extends JavaModule { outer =>
    * @return
    */
   def scalaOrganization: T[String] = T {
-    if (isDotty(scalaVersion()))
+    if (ZincWorkerUtil.isDotty(scalaVersion()))
       "ch.epfl.lamp"
     else
       "org.scala-lang"
@@ -76,9 +67,9 @@ trait ScalaModule extends JavaModule { outer =>
   override def mapDependencies: Task[coursier.Dependency => coursier.Dependency] = T.task {
     d: coursier.Dependency =>
       val artifacts =
-        if (isDotty(scalaVersion()))
+        if (ZincWorkerUtil.isDotty(scalaVersion()))
           Set("dotty-library", "dotty-compiler")
-        else if (isScala3(scalaVersion()))
+        else if (ZincWorkerUtil.isScala3(scalaVersion()))
           Set("scala3-library", "scala3-compiler")
         else
           Set("scala-library", "scala-compiler", "scala-reflect")
@@ -134,7 +125,7 @@ trait ScalaModule extends JavaModule { outer =>
 
   def scalaDocOptions: T[Seq[String]] = T {
     val defaults =
-      if (isDottyOrScala3(scalaVersion()))
+      if (ZincWorkerUtil.isDottyOrScala3(scalaVersion()))
         Seq(
           "-project",
           artifactName()
@@ -226,7 +217,9 @@ trait ScalaModule extends JavaModule { outer =>
 
   override def docSources: Sources = T.sources {
     // Scaladoc 3.0.0 is consuming tasty files
-    if (isScala3(scalaVersion()) && !isScala3Milestone(scalaVersion())) Seq(compile().classes)
+    if (
+      ZincWorkerUtil.isScala3(scalaVersion()) && !ZincWorkerUtil.isScala3Milestone(scalaVersion())
+    ) Seq(compile().classes)
     else allSources()
   }
 
@@ -260,7 +253,9 @@ trait ScalaModule extends JavaModule { outer =>
       }
     }
 
-    if (isDotty(scalaVersion()) || isScala3Milestone(scalaVersion())) { // dottydoc
+    if (
+      ZincWorkerUtil.isDotty(scalaVersion()) || ZincWorkerUtil.isScala3Milestone(scalaVersion())
+    ) { // dottydoc
       val javadocDir = T.dest / "javadoc"
       os.makeDir.all(javadocDir)
 
@@ -288,7 +283,7 @@ trait ScalaModule extends JavaModule { outer =>
         javadocDir / "_site"
       )
 
-    } else if (isScala3(scalaVersion())) { // scaladoc 3
+    } else if (ZincWorkerUtil.isScala3(scalaVersion())) { // scaladoc 3
       val javadocDir = T.dest / "javadoc"
       os.makeDir.all(javadocDir)
 
@@ -357,7 +352,7 @@ trait ScalaModule extends JavaModule { outer =>
     } else {
       Jvm.runSubprocess(
         mainClass =
-          if (isDottyOrScala3(scalaVersion()))
+          if (ZincWorkerUtil.isDottyOrScala3(scalaVersion()))
             "dotty.tools.repl.Main"
           else
             "scala.tools.nsc.MainGenericRunner",
@@ -438,7 +433,7 @@ trait ScalaModule extends JavaModule { outer =>
    */
   def artifactScalaVersion: T[String] = T {
     if (crossFullScalaVersion()) scalaVersion()
-    else mill.scalalib.api.Util.scalaBinaryVersion(scalaVersion())
+    else ZincWorkerUtil.scalaBinaryVersion(scalaVersion())
   }
 
   /**
@@ -448,13 +443,31 @@ trait ScalaModule extends JavaModule { outer =>
 
   override def artifactId: T[String] = artifactName() + artifactSuffix()
 
+  /**
+   * @param hint "all" - fetch all dependencies,
+   *             "ammonite" - fetch ammonite dependencies,
+   *             "compiler" - fetch all compiler dependencies
+   */
   @nowarn("msg=pure expression does nothing")
-  override def prepareOffline(): Command[Unit] = T.command {
-    super.prepareOffline()()
-    resolveDeps(scalacPluginIvyDeps)()
-    resolveDeps(scalaDocPluginIvyDeps)()
-    resolvedAmmoniteReplIvyDeps()
-    ()
+  override def prepareOffline(hint: String*): Command[Unit] = {
+    val withAmmonite = hint.contains("all") || hint.contains("ammonite")
+    val withCompiler = hint.contains("all") || hint.contains("compiler")
+
+    val tasks = Seq(
+      if (withAmmonite) Seq(resolvedAmmoniteReplIvyDeps) else Seq(),
+      if (withCompiler) Seq(T.task {
+        zincWorker.scalaCompilerBridgeJar(scalaVersion(), scalaOrganization(), repositoriesTask())
+      })
+      else Seq()
+    ).flatten
+
+    T.command {
+      super.prepareOffline(hint: _*)()
+      resolveDeps(scalacPluginIvyDeps)()
+      resolveDeps(scalaDocPluginIvyDeps)()
+      T.sequence(tasks)()
+      ()
+    }
   }
 
   override def manifest: T[Jvm.JarManifest] = T {
@@ -475,7 +488,7 @@ trait ScalaModule extends JavaModule { outer =>
       new ScalaBuildTarget(
         scalaOrganization(),
         scalaVersion(),
-        scalaBinaryVersion(scalaVersion()),
+        ZincWorkerUtil.scalaBinaryVersion(scalaVersion()),
         ScalaPlatform.JVM,
         scalaCompilerClasspath().map(_.path.toNIO.toUri.toString).iterator.toSeq.asJava
       )

scalalib/src/ZincWorkerModule.scala

@@ -151,13 +151,13 @@ trait ZincWorkerModule extends mill.Module with OfflineSupportModule { self: Cou
   }
 
   @nowarn("msg=pure expression does nothing")
-  override def prepareOffline(): Command[Unit] =
+  override def prepareOffline(hint: String*): Command[Unit] = {
     T.command {
-      super.prepareOffline()()
+      super.prepareOffline(hint: _*)()
       classpath()
-      // worker()
       ()
     }
+  }
 
   @nowarn("msg=pure expression does nothing")
   def prepareOfflineCompiler(scalaVersion: String, scalaOrganization: String): Command[Unit] =

scalalib/src/mill/scalalib/OfflineSupportModule.scala

@@ -8,7 +8,7 @@ trait OfflineSupportModule extends mill.Module {
   /**
    * Prepare the module for working offline. This should typically fetch (missing) resources like ivy dependencies.
    */
-  def prepareOffline(): Command[Unit] = T.command {
+  def prepareOffline(hint: String*): Command[Unit] = T.command {
     // nothing to do
   }