Implement scalafmt-dynamic downloader using sbt

Reduce dependency to scalafmt-dynamic-core, which does not depend on own
version of coursier.

Author: kitbellew

build.sbt

@@ -63,7 +63,7 @@ lazy val plugin = project.enablePlugins(SbtPlugin, ScriptedPlugin).settings(
     "com.googlecode.java-diff-utils" % "diffutils" % "1.3.0",
     "org.scalameta" %% "scalafmt-sysops" % scalafmtVersion cross
       CrossVersion.for3Use2_13,
-    "org.scalameta" %% "scalafmt-dynamic" % scalafmtVersion cross
+    "org.scalameta" %% "scalafmt-dynamic-core" % scalafmtVersion cross
       CrossVersion.for3Use2_13,
   ),
   scriptedBufferLog := false,

plugin/src/main/scala/org/scalafmt/sbt/ScalafmtPlugin.scala

@@ -4,7 +4,7 @@ import java.io.OutputStreamWriter
 import java.nio.file.{Files, Path}
 
 import sbt.Keys.*
-import sbt.librarymanagement.MavenRepository
+import sbt.librarymanagement as lm
 import sbt.util.CacheImplicits.*
 import sbt.util.{CacheStoreFactory, FileInfo, Level}
 import sbt.{given, *}
@@ -102,7 +102,7 @@ object ScalafmtPlugin extends AutoPlugin {
   private type Output = String
   private type InitTask = Def.Initialize[Task[Unit]]
 
-  val globalInstance = Scalafmt.create(this.getClass.getClassLoader)
+  private val globalInstance = Scalafmt.create(this.getClass.getClassLoader)
     .withRespectProjectFilters(true)
 
   private object FilterMode {
@@ -133,6 +133,8 @@ object ScalafmtPlugin extends AutoPlugin {
       currentProject: ResolvedProject,
       filterMode: String,
       errorHandling: ErrorHandling,
+      dependencyResolution: lm.DependencyResolution,
+      updateConfiguration: lm.UpdateConfiguration,
   ) {
     locally {
       def cmp[A: Ordering](x: Iterable[A], y: Iterable[A]): Int = Ordering
@@ -162,8 +164,10 @@ object ScalafmtPlugin extends AutoPlugin {
       errorHandling,
     )
 
-    private val scalafmtSession = {
-      val repositories = resolvers.collect { case r: MavenRepository => r.root }
+    private def getFallbackInstance = {
+      val repositories = resolvers.collect { case r: lm.MavenRepository =>
+        r.root
+      }
       val repoCredentials = credentials.flatMap { c =>
         Try(CredentialsUtils.toDirect(c)).toOption
           .map(dc => new RepositoryCredential(dc.host, dc.userName, dc.passwd))
@@ -175,10 +179,21 @@ object ScalafmtPlugin extends AutoPlugin {
         info.mkString("Adding credentials [", ",", "]")
       }
 
-      val scalafmtSession = globalInstance.withReporter(reporter)
-        .withMavenRepositories(repositories*)
+      globalInstance.withMavenRepositories(repositories*)
         .withRepositoryCredentials(repoCredentials*)
-        .createSession(config.toAbsolutePath)
+    }
+
+    private val scalafmtSession = {
+      val factory = new ScalafmtSbtDependencyDownloader(
+        taskStreams,
+        dependencyResolution,
+        updateConfiguration,
+      )
+
+      val withFactory = globalInstance.withRepositoryPackageDownloader(factory)
+      val scalafmtSession = {
+        if (withFactory ne globalInstance) withFactory else getFallbackInstance
+      }.withReporter(reporter).createSession(config.toAbsolutePath)
       if (scalafmtSession == null) throw messageException(
         "failed to create formatting session. Please report bug to https://github.com/scalameta/sbt-scalafmt",
       )
@@ -473,6 +488,8 @@ object ScalafmtPlugin extends AutoPlugin {
           !noThrow && scalafmtFailOnErrors.value,
           scalafmtDetailedError.value,
         ),
+        dependencyResolution.value,
+        updateConfiguration.value,
       )
       func(files, dirs, session)
     }
@@ -519,6 +536,8 @@ object ScalafmtPlugin extends AutoPlugin {
           scalafmtFailOnErrors.value,
           scalafmtDetailedError.value,
         ),
+        dependencyResolution.value,
+        updateConfiguration.value,
       ).formatSources(absFiles, Nil)
     },
   ))

plugin/src/main/scala/org/scalafmt/sbt/ScalafmtSbtDependencyDownloader.scala

@@ -0,0 +1,55 @@
+package org.scalafmt.sbt
+
+import java.io.File
+import java.lang as jl
+
+import sbt.Keys.TaskStreams
+import sbt.internal.librarymanagement.InternalDefaults.{
+  modulePrefixTemp, sbtOrgTemp,
+}
+import sbt.{librarymanagement as lm, richUpdateReport}
+
+import org.scalafmt.CompatCollections.JavaConverters.*
+import org.scalafmt.interfaces.*
+
+class ScalafmtSbtDependencyDownloader(
+    taskStreams: TaskStreams,
+    dependencyResolution: lm.DependencyResolution,
+    updateConfiguration: lm.UpdateConfiguration,
+) extends RepositoryPackageDownloaderFactory with RepositoryPackageDownloader {
+  override def create(
+      reporter: ScalafmtReporter,
+      properties: RepositoryProperties,
+  ): RepositoryPackageDownloader = this
+
+  override def download(
+      scalaVersion: String,
+      scalafmtVersion: String,
+      reporter: ScalafmtReporter,
+      dependencies: jl.Iterable[RepositoryPackage],
+  ): jl.Iterable[File] = {
+    val name = s"${modulePrefixTemp}scalafmt-${scalafmtVersion}_$scalaVersion"
+    val moduleId = lm.ModuleID(sbtOrgTemp, name, "1.0")
+    val scalaModule = lm.ScalaModuleInfo(
+      scalaFullVersion = scalaVersion,
+      scalaBinaryVersion = lm.CrossVersion.binaryScalaVersion(scalaVersion),
+      configurations = Vector.empty,
+      checkExplicit = true,
+      filterImplicit = true,
+      overrideScalaVersion = false, // disables autoScalaLibrary
+    )
+    val moduleDependencies = dependencies.asScala
+      .map(d => lm.ModuleID(d.group, d.artifact, d.version)).toVector
+    val moduleConf = lm
+      .ModuleDescriptorConfiguration(moduleId, lm.ModuleInfo("sandbox"))
+      .withDependencies(moduleDependencies).withScalaModuleInfo(scalaModule)
+
+    dependencyResolution.update(
+      dependencyResolution.moduleDescriptor(moduleConf),
+      updateConfiguration,
+      lm.UnresolvedWarningConfiguration(),
+      taskStreams.log,
+    ).fold(x => throw x.resolveException, x => x.allFiles.asJava)
+  }
+
+}