single file test

metals/src/main/scala/scala/meta/internal/metals/FallbackMetalsLspService.scala

@@ -47,6 +47,10 @@ class FallbackMetalsLspService(
       folderVisibleName,
       headDoctor,
     ) {
+
+  buildServerPromise.success(())
+  indexingPromise.success(())
+
   private val files: AtomicReference[Set[AbsolutePath]] = new AtomicReference(
     Set.empty
   )

metals/src/main/scala/scala/meta/internal/metals/MetalsLspService.scala

@@ -2152,10 +2152,12 @@ class MetalsLspService(
       }
 
     val scalaCliServers = scalaCli.servers
-    val scalaCliBuildChanges = otherChanges.groupBy { change =>
+    val groupedByServer = otherChanges.groupBy { change =>
       val connOpt = buildTargets.buildServerOf(change.getTarget)
       connOpt.flatMap(conn => scalaCliServers.find(_ == conn))
     }
+    val scalaCliAffectedServers = groupedByServer.collect { case (Some(server), _) => server }
+    val mainConnectionChanges = groupedByServer.get(None)
 
     if (ammoniteChanges.nonEmpty)
       ammonite.importBuild().onComplete {
@@ -2164,9 +2166,8 @@ class MetalsLspService(
           scribe.error("Error re-importing Ammonite build", exception)
       }
 
-    scalaCliBuildChanges.collect { case (Some(server), _) =>
-      server
-        .importBuild()
+    scalaCliAffectedServers.map { server =>
+      server.importBuild()
         .onComplete {
           case Success(()) =>
           case Failure(exception) =>
@@ -2178,7 +2179,7 @@ class MetalsLspService(
         }
     }
 
-    if (scalaCliBuildChanges.exists(_._1.isEmpty)) {
+    if (mainConnectionChanges.nonEmpty) {
       bspSession match {
         case None => scribe.warn("No build server connected")
         case Some(session) =>

metals/src/main/scala/scala/meta/internal/metals/WorkspaceFolders.scala

@@ -18,10 +18,7 @@ class WorkspaceFolders(
 
   private val folderServices: AtomicReference[WorkspaceFoldersServices] = {
     val (scalaProjects, nonScalaProjects) =
-      initialFolders.partition(_.isMetalsProject) match {
-        case (Nil, nonScala) => (List(nonScala.head), nonScala.tail)
-        case t => t
-      }
+      initialFolders.partition(_.isMetalsProject)
     val services = scalaProjects.map(createService(_))
     new AtomicReference(WorkspaceFoldersServices(services, nonScalaProjects))
   }

metals/src/main/scala/scala/meta/internal/metals/scalacli/ScalaCliServers.scala

@@ -41,7 +41,6 @@ class ScalaCliServers(
     buildTargets: BuildTargets,
 )(implicit ec: ExecutionContextExecutorService)
     extends Cancelable {
-  val buildTargetsData = new TargetData
   private val serversRef: AtomicReference[Set[ScalaCli]] = new AtomicReference(
     Set.empty
   )

metals/src/main/scala/scala/meta/metals/MetalsLanguageServer.scala

@@ -172,9 +172,9 @@ class MetalsLanguageServer(
           if (folderPathsWithScala.nonEmpty) folderPathsWithScala
           else List(fallbackServicePath)
 
-          folderPathsWithScala.foreach(folder =>
-            new StdReportContext(folder.toNIO, _ => None).cleanUpOldReports()
-          )
+        folderPathsWithScala.foreach(folder =>
+          new StdReportContext(folder.toNIO, _ => None).cleanUpOldReports()
+        )
 
         MetalsLogger.setupLspLogger(
           logPaths,

tests/unit/src/main/scala/tests/BaseLspSuite.scala

@@ -96,7 +96,7 @@ abstract class BaseLspSuite(
       server,
       client,
       expectError,
-      layout.keys.toList,
+      Some(layout.keys.toList),
     )
   }
 

tests/unit/src/main/scala/tests/BuildServerInitializer.scala

@@ -23,7 +23,7 @@ sealed trait BuildServerInitializer {
       server: TestingServer,
       client: TestingClient,
       expectError: Boolean,
-      workspaceFolders: List[String] = Nil,
+      workspaceFolders: Option[List[String]] = None,
   )(implicit ec: ExecutionContext): Future[InitializeResult]
 }
 
@@ -38,11 +38,13 @@ object QuickBuildInitializer extends BuildServerInitializer {
       server: TestingServer,
       client: TestingClient,
       expectError: Boolean,
-      workspaceFolders: List[String] = Nil,
+      workspaceFolders: Option[List[String]] = None,
   )(implicit ec: ExecutionContext): Future[InitializeResult] = {
     val foldersToInit =
-      if (workspaceFolders.nonEmpty) workspaceFolders.map(workspace.resolve)
-      else List(workspace)
+      workspaceFolders match {
+        case Some(workspaceFolders) => workspaceFolders.map(workspace.resolve)
+        case None => List(workspace)
+      }
     foldersToInit.foreach(QuickBuild.bloopInstall)
     for {
       initializeResult <- server.initialize(workspaceFolders)
@@ -67,7 +69,7 @@ object BloopImportInitializer extends BuildServerInitializer {
       server: TestingServer,
       client: TestingClient,
       expectError: Boolean,
-      workspaceFolders: List[String] = Nil,
+      workspaceFolders: Option[List[String]] = None,
   )(implicit ec: ExecutionContext): Future[InitializeResult] = {
     for {
       initializeResult <- server.initialize()
@@ -95,11 +97,12 @@ object SbtServerInitializer extends BuildServerInitializer {
       server: TestingServer,
       client: TestingClient,
       expectError: Boolean,
-      workspaceFolders: List[String] = Nil,
+      workspaceFolders: Option[List[String]] = None,
   )(implicit ec: ExecutionContext): Future[InitializeResult] = {
-    val paths =
-      if (workspaceFolders.isEmpty) List(workspace)
-      else workspaceFolders.map(workspace.resolve)
+    val paths = workspaceFolders match {
+      case Some(workspaceFolders) => workspaceFolders.map(workspace.resolve)
+      case None => List(workspace)
+    }
     paths.foreach { path =>
       val sbtVersion =
         SbtBuildTool
@@ -174,7 +177,7 @@ object MillServerInitializer extends BuildServerInitializer {
       server: TestingServer,
       client: TestingClient,
       expectError: Boolean,
-      workspaceFolders: List[String] = Nil,
+      workspaceFolders: Option[List[String]] = None,
   )(implicit ec: ExecutionContext): Future[InitializeResult] = {
     for {
       initializeResult <- server.initialize()

tests/unit/src/main/scala/tests/TestingServer.scala

@@ -538,7 +538,7 @@ final case class TestingServer(
   }
 
   def initialize(
-      workspaceFolders: List[String] = Nil
+      workspaceFolders: Option[List[String]] = None
   ): Future[l.InitializeResult] = {
     val params = new InitializeParams
     val workspaceCapabilities = new WorkspaceClientCapabilities()
@@ -578,12 +578,18 @@ final case class TestingServer(
         Map.empty.asJava.toJson,
       )
     )
-    params.setWorkspaceFolders(
-      workspaceFolders
-        .map(file => new WorkspaceFolder(toPath(file).toURI.toString))
-        .asJava
-    )
-    params.setRootUri(workspace.toURI.toString)
+
+    workspaceFolders match {
+      case Some(workspaceFolders) =>
+        params.setWorkspaceFolders(
+          workspaceFolders
+            .map(file => new WorkspaceFolder(toPath(file).toURI.toString))
+            .asJava
+        )
+      case None =>
+        params.setRootUri(workspace.toURI.toString)
+    }
+
     languageServer.initialize(params).asScala
   }
 

tests/unit/src/test/scala/tests/SingleFileSuite.scala

@@ -0,0 +1,28 @@
+package tests
+
+class SingleFileSuite extends BaseCompletionLspSuite("workspaceFolderSuite") {
+
+  test("basic") {
+    cleanWorkspace()
+    writeLayout(
+      """|/A.scala
+         |case class MyObjectA() {
+         |  val i: Int = "aaa"
+         |}
+         |""".stripMargin
+    )
+    for {
+      _ <- initialize(Map.empty[String, String], expectError = false)
+      _ <- server.didOpen("A.scala")
+      _ = assertNoDiff(
+        server.client.workspaceDiagnostics,
+        """|A.scala:2:16: error: Found:    ("aaa" : String)
+           |Required: Int
+           |  val i: Int = "aaa"
+           |               ^^^^^
+           |""".stripMargin,
+      )
+    } yield ()
+  }
+
+}