Remove redundant path calculation from Completions in PC (#18889)

Author: rochala

presentation-compiler/src/main/dotty/tools/pc/completions/CompletionProvider.scala

@@ -52,19 +52,15 @@ class CompletionProvider(
     val pos = driver.sourcePosition(params)
     val (items, isIncomplete) = driver.compilationUnits.get(uri) match
       case Some(unit) =>
-        val path =
-          Interactive.pathTo(driver.openedTrees(uri), pos)(using ctx)
 
         val newctx = ctx.fresh.setCompilationUnit(unit)
-        val tpdPath =
-          Interactive.pathTo(newctx.compilationUnit.tpdTree, pos.span)(
-            using newctx
-          )
+        val tpdPath = Interactive.pathTo(newctx.compilationUnit.tpdTree, pos.span)(using newctx)
+
         val locatedCtx =
           Interactive.contextOfPath(tpdPath)(using newctx)
         val indexedCtx = IndexedContext(locatedCtx)
         val completionPos =
-          CompletionPos.infer(pos, params, path)(using newctx)
+          CompletionPos.infer(pos, params, tpdPath)(using newctx)
         val autoImportsGen = AutoImports.generator(
           completionPos.sourcePos,
           text,
@@ -82,7 +78,7 @@ class CompletionProvider(
             buildTargetIdentifier,
             completionPos,
             indexedCtx,
-            path,
+            tpdPath,
             config,
             folderPath,
             autoImportsGen,
@@ -96,7 +92,7 @@ class CompletionProvider(
             idx,
             autoImportsGen,
             completionPos,
-            path,
+            tpdPath,
             indexedCtx
           )(using newctx)
         }

presentation-compiler/src/main/dotty/tools/pc/completions/Completions.scala

@@ -121,7 +121,7 @@ class Completions(
         val allAdvanced = advanced ++ keywords
         path match
           // should not show completions for toplevel
-          case Nil if pos.source.file.extension != "sc" =>
+          case Nil | (_: PackageDef) :: _ if pos.source.file.extension != "sc" =>
             (allAdvanced, SymbolSearch.Result.COMPLETE)
           case Select(qual, _) :: _ if qual.tpe.isErroneous =>
             (allAdvanced, SymbolSearch.Result.COMPLETE)

presentation-compiler/src/main/dotty/tools/pc/completions/KeywordsCompletions.scala

@@ -26,7 +26,7 @@ object KeywordsCompletions:
       checkIfNotInComment(completionPos.cursorPos, comments)
 
     path match
-      case Nil if completionPos.query.isEmpty() =>
+      case Nil | (_: PackageDef) :: _ if completionPos.query.isEmpty() =>
         Keyword.all.collect {
           // topelevel definitions are allowed in Scala 3
           case kw if (kw.isPackage || kw.isTemplate) && notInComment =>
@@ -78,7 +78,7 @@ object KeywordsCompletions:
 
   private def isPackage(enclosing: List[Tree]): Boolean =
     enclosing match
-      case Nil => true
+      case Nil | (_: PackageDef) :: _ => true
       case _ => false
 
   private def isParam(enclosing: List[Tree]): Boolean =

presentation-compiler/src/main/dotty/tools/pc/completions/ScalaCliCompletions.scala

@@ -16,12 +16,11 @@ class ScalaCliCompletions(
       pos.lineContent.take(pos.column).stripPrefix("/*<script>*/")
     )
     path match
-      case Nil => scalaCliDep
+      case Nil | (_: PackageDef) :: _ => scalaCliDep
       // generated script file will end with .sc.scala
-      case (_: TypeDef) :: Nil if pos.source.file.path.endsWith(".sc.scala") =>
+      case (_: TypeDef) :: (_: PackageDef) :: Nil if pos.source.file.path.endsWith(".sc.scala") =>
         scalaCliDep
-      case (_: Template) :: (_: TypeDef) :: Nil
-          if pos.source.file.path.endsWith(".sc.scala") =>
+      case (_: Template) :: (_: TypeDef) :: Nil if pos.source.file.path.endsWith(".sc.scala") =>
         scalaCliDep
       case head :: next => None