From 72bd65cb5a88f57015fc9acbeae07c423b820f96 Mon Sep 17 00:00:00 2001
From: Tomasz Godzik <tgodzik@virtuslab.com>
Date: Thu, 19 Oct 2023 18:46:42 +0200
Subject: [PATCH] bugfix: Add back unintentionlly removed support for 2.11.x

Previously, we would use the lates scalfix version by default, which doesn't support Scala 2.11 by default. Now, we fall back to the latest version that supported it.
---
 .../internal/metals/ScalafixProvider.scala    | 42 +++++++++++++++++--
 .../feature/Scala211ActionsLspSuite.scala     | 40 ++++++++++++++++++
 2 files changed, 79 insertions(+), 3 deletions(-)
 create mode 100644 tests/slow/src/test/scala/tests/feature/Scala211ActionsLspSuite.scala

diff --git a/metals/src/main/scala/scala/meta/internal/metals/ScalafixProvider.scala b/metals/src/main/scala/scala/meta/internal/metals/ScalafixProvider.scala
index 45e43513293..00143378c95 100644
--- a/metals/src/main/scala/scala/meta/internal/metals/ScalafixProvider.scala
+++ b/metals/src/main/scala/scala/meta/internal/metals/ScalafixProvider.scala
@@ -18,18 +18,22 @@ import scala.meta.internal.metals.MetalsEnrichments._
 import scala.meta.internal.metals.clients.language.MetalsLanguageClient
 import scala.meta.internal.metals.clients.language.MetalsQuickPickItem
 import scala.meta.internal.metals.clients.language.MetalsQuickPickParams
+import scala.meta.internal.metals.{BuildInfo => V}
 import scala.meta.internal.mtags.SemanticdbClasspath
 import scala.meta.internal.semanticdb.TextDocuments
 import scala.meta.io.AbsolutePath
 
 import com.typesafe.config.ConfigFactory
 import coursierapi.Dependency
+import coursierapi.Repository
 import org.eclipse.lsp4j.MessageParams
 import org.eclipse.lsp4j.MessageType
 import org.eclipse.{lsp4j => l}
 import scalafix.interfaces.Scalafix
 import scalafix.interfaces.ScalafixEvaluation
 import scalafix.interfaces.ScalafixFileEvaluationError
+import scalafix.internal.interfaces.ScalafixCoursier
+import scalafix.internal.interfaces.ScalafixInterfacesClassloader
 
 case class ScalafixProvider(
     buffers: Buffers,
@@ -437,7 +441,9 @@ case class ScalafixProvider(
       case None =>
         statusBar.trackBlockingTask("Downloading scalafix") {
           val scalafix =
-            Try(Scalafix.fetchAndClassloadInstance(scalaBinaryVersion))
+            if (scalaBinaryVersion == "2.11") Try(scala211Fallback)
+            else
+              Try(Scalafix.fetchAndClassloadInstance(scalaBinaryVersion))
           scalafix.foreach(api => scalafixCache.update(scalaBinaryVersion, api))
           scalafix
         }
@@ -445,6 +451,22 @@ case class ScalafixProvider(
 
   }
 
+  private def scala211Fallback: Scalafix = {
+    // last version that supports Scala 2.11.12
+    val latestSupporting = "0.10.4"
+    val jars = ScalafixCoursier.scalafixCliJars(
+      Repository.defaults(),
+      latestSupporting,
+      V.scala211,
+    )
+    val parent = new ScalafixInterfacesClassloader(
+      classOf[Scalafix].getClassLoader()
+    );
+    Scalafix.classloadInstance(
+      new URLClassLoader(jars.asScala.toArray, parent)
+    );
+  }
+
   private def getRuleClassLoader(
       scalfixRulesKey: ScalafixRulesClasspathKey,
       scalafixClassLoader: ClassLoader,
@@ -457,8 +479,22 @@ case class ScalafixProvider(
         ) {
           val rulesDependencies = scalfixRulesKey.usedRulesWithClasspath
           val organizeImportRule =
+            // Scalafix version that supports Scala 2.11 doesn't have the rule built in
+            if (scalfixRulesKey.scalaBinaryVersion == "2.11")
+              Some(
+                Dependency.of(
+                  "com.github.liancheng",
+                  "organize-imports_" + scalfixRulesKey.scalaBinaryVersion,
+                  "0.6.0",
+                )
+              )
+            else None
+
+          val allRules =
             Try(
-              Embedded.rulesClasspath(rulesDependencies.toList)
+              Embedded.rulesClasspath(
+                rulesDependencies.toList ++ organizeImportRule
+              )
             ).map { paths =>
               val classloader = Embedded.toClassLoader(
                 Classpath(paths.map(AbsolutePath(_))),
@@ -467,7 +503,7 @@ case class ScalafixProvider(
               rulesClassloaderCache.update(scalfixRulesKey, classloader)
               classloader
             }
-          organizeImportRule
+          allRules
         }
     }
   }
diff --git a/tests/slow/src/test/scala/tests/feature/Scala211ActionsLspSuite.scala b/tests/slow/src/test/scala/tests/feature/Scala211ActionsLspSuite.scala
new file mode 100644
index 00000000000..eebecc7741b
--- /dev/null
+++ b/tests/slow/src/test/scala/tests/feature/Scala211ActionsLspSuite.scala
@@ -0,0 +1,40 @@
+package tests.feature
+
+import scala.meta.internal.metals.BuildInfo
+import scala.meta.internal.metals.codeactions.SourceOrganizeImports
+
+import tests.codeactions.BaseCodeActionLspSuite
+
+class Scala211ActionsLspSuite
+    extends BaseCodeActionLspSuite("cross-code-actions") {
+
+  override protected val scalaVersion: String = BuildInfo.scala211
+
+  check(
+    "basic",
+    """
+      |package a
+      |import scala.concurrent.duration._
+      |import scala.concurrent.Future<<>>
+      |import scala.concurrent.ExecutionContext.global
+      |
+      |object A {
+      |  val d = Duration(10, MICROSECONDS)
+      |  val k = Future.successful(1)
+      |}
+      |""".stripMargin,
+    s"${SourceOrganizeImports.title}",
+    """
+      |package a
+      |import scala.concurrent.Future
+      |import scala.concurrent.duration._
+      |
+      |object A {
+      |  val d = Duration(10, MICROSECONDS)
+      |  val k = Future.successful(1)
+      |}
+      |""".stripMargin,
+    kind = List(SourceOrganizeImports.kind),
+    scalacOptions = List("-Ywarn-unused-import"),
+  )
+}