fix: use alternative with stripped synthetic filename$package.

mtags-shared/src/main/scala/scala/meta/internal/metals/ProxySymbolDocumentation.scala

@@ -0,0 +1,18 @@
+package scala.meta.internal.metals
+
+import java.util
+import java.util.Collections
+
+import scala.meta.pc.SymbolDocumentation
+
+case class ProxySymbolDocumentation(orginalSymbol: String)
+    extends SymbolDocumentation {
+  override def symbol(): String = ""
+  override def displayName(): String = ""
+  override def docstring(): String = ""
+  override def defaultValue(): String = ""
+  override def typeParameters(): util.List[SymbolDocumentation] =
+    Collections.emptyList()
+  override def parameters(): util.List[SymbolDocumentation] =
+    Collections.emptyList()
+}

mtags/src/main/scala-2/scala/meta/internal/pc/CompletionItemResolver.scala

@@ -75,7 +75,7 @@ class CompletionItemResolver(
       }
     } else {
       val companionDoc = docs(companion)
-      if (companionDoc.isEmpty) gsymDoc
+      if (companionDoc.isEmpty || companionDoc == gsymDoc) gsymDoc
       else if (gsymDoc.isEmpty) companionDoc
       else {
         List(

mtags/src/main/scala-3/scala/meta/internal/mtags/MtagsEnrichments.scala

@@ -230,9 +230,10 @@ object MtagsEnrichments extends ScalametaCommonEnrichments:
     def stripBackticks: String = s.stripPrefix("`").stripSuffix("`")
 
   extension (search: SymbolSearch)
-    def symbolDocumentation(symbol: Symbol, contentType: ContentType = ContentType.MARKDOWN)(using
-        Context
-    ): Option[SymbolDocumentation] =
+    def symbolDocumentation(
+      symbol: Symbol,
+      contentType: ContentType = ContentType.MARKDOWN
+    )(using Context): Option[SymbolDocumentation] =
       def toSemanticdbSymbol(symbol: Symbol) =
         SemanticdbSymbols.symbolName(
           if !symbol.is(JavaDefined) && symbol.isPrimaryConstructor then

mtags/src/main/scala-3/scala/meta/internal/pc/CompletionItemResolver.scala

@@ -71,7 +71,7 @@ object CompletionItemResolver extends ItemResolver:
       else gsymDoc
     else
       val companionDoc = docs(companion)
-      if companionDoc.isEmpty then gsymDoc
+      if companionDoc.isEmpty || companionDoc == gsymDoc then gsymDoc
       else if gsymDoc.isEmpty then companionDoc
       else
         List(

mtags/src/main/scala/scala/meta/internal/metals/Docstrings.scala

@@ -40,16 +40,15 @@ class Docstrings(index: GlobalSymbolIndex) {
       parents: ParentSymbols,
       contentType: ContentType
   ): Optional[SymbolDocumentation] = {
-    val content = Content.from(symbol, contentType)
-    val result = cache.get(content) match {
+    val result = getFromCacheWithProxy(symbol, contentType) match {
       case Some(value) =>
         if (value == EmptySymbolDocumentation) None
         else Some(value)
       case None =>
         indexSymbol(symbol, contentType)
-        val result = cache.get(content)
+        val result = getFromCacheWithProxy(symbol, contentType)
         if (result.isEmpty)
-          cache(content) = EmptySymbolDocumentation
+          cache(Content.from(symbol, contentType)) = EmptySymbolDocumentation
         result
     }
     /* Fall back to parent javadocs/scaladocs if nothing is specified for the current symbol
@@ -83,11 +82,9 @@ class Docstrings(index: GlobalSymbolIndex) {
       .parents()
       .asScala
       .flatMap { s =>
-        val content = Content.from(s, contentType)
-        if (cache.contains(content)) cache.get(content)
-        else {
+        getFromCacheWithProxy(s, contentType).orElse {
           indexSymbol(s, contentType)
-          cache.get(content)
+          getFromCacheWithProxy(s, contentType)
         }
       }
       .find(_.docstring().nonEmpty)
@@ -100,6 +97,17 @@ class Docstrings(index: GlobalSymbolIndex) {
       }
   }
 
+  private def getFromCacheWithProxy(
+      symbol: String,
+      contentType: ContentType
+  ): Option[SymbolDocumentation] = {
+    cache.get(Content.from(symbol, contentType)) match {
+      case Some(ProxySymbolDocumentation(alternativeSymbol)) =>
+        cache.get(Content.from(alternativeSymbol, contentType))
+      case res => res
+    }
+  }
+
   /**
    * Expire all symbols showed in the given scala source file.
    *
@@ -130,6 +138,7 @@ class Docstrings(index: GlobalSymbolIndex) {
       case Some(defn) =>
         try {
           indexSymbolDefinition(defn, contentType)
+          maybeCacheAlternative(defn, contentType)
         } catch {
           case NonFatal(e) =>
             logger.log(Level.SEVERE, defn.path.toURI.toString, e)
@@ -138,6 +147,22 @@ class Docstrings(index: GlobalSymbolIndex) {
     }
   }
 
+  private def maybeCacheAlternative(
+      defn: SymbolDefinition,
+      contentType: ContentType
+  ) = {
+    val defSymbol = defn.definitionSymbol.value
+    val querySymbol = defn.querySymbol.value
+    lazy val queryContent = Content.from(querySymbol, contentType)
+
+    if (
+      defSymbol != querySymbol && cache.get(queryContent).forall {
+        case EmptySymbolDocumentation | _: ProxySymbolDocumentation => true
+        case _ => false
+      }
+    ) cache.put(queryContent, new ProxySymbolDocumentation(defSymbol))
+  }
+
   private def indexSymbolDefinition(
       defn: SymbolDefinition,
       contentType: ContentType
@@ -166,7 +191,7 @@ class Docstrings(index: GlobalSymbolIndex) {
     ): Unit = {
       for {
         contentType <- ContentType.values()
-      } cache.remove(Content.from(occ.symbol, contentType))
+      } cache.remove(Content.from(sinfo.symbol, contentType))
     }
   }
 

mtags/src/main/scala/scala/meta/internal/mtags/DefinitionAlternatives.scala

@@ -9,6 +9,7 @@ object DefinitionAlternatives {
    */
   def apply(symbol: Symbol): List[Symbol] = {
     List(
+      stripSyntheticPackageObjectFromObject(symbol),
       caseClassCompanionToType(symbol),
       caseClassApplyOrCopy(symbol),
       caseClassApplyOrCopyParams(symbol),
@@ -26,6 +27,21 @@ object DefinitionAlternatives {
       Some(sym.owner -> sym.value.desc)
   }
 
+  private def stripSyntheticPackageObjectFromObject(
+      symbol: Symbol
+  ): Option[Symbol] = {
+    val toplevel = symbol.toplevel
+    Option(toplevel).flatMap {
+      case GlobalSymbol(owner, Descriptor.Term(pkgName))
+          if pkgName.endsWith("$package") =>
+        val newSymbol =
+          Symbol(s"${owner.value}${symbol.value.stripPrefix(toplevel.value)}")
+        if (newSymbol.toplevel.isTerm) Some(newSymbol)
+        else None
+      case _ => None
+    }
+  }
+
   /**
    * If `case class A(a: Int)` and there is no companion object, resolve
    * `A` in `A(1)` to the class definition.

mtags/src/main/scala/scala/meta/internal/mtags/ScalametaCommonEnrichments.scala

@@ -363,6 +363,9 @@ trait ScalametaCommonEnrichments extends CommonMtagsEnrichments {
 
     def filename: String = path.toNIO.filename
 
+    def scalaFileName: String =
+      path.filename.stripSuffix(".scala").stripSuffix(".sc")
+
     def toIdeallyRelativeURI(sourceItemOpt: Option[AbsolutePath]): String =
       sourceItemOpt match {
         case Some(sourceItem) =>

mtags/src/main/scala/scala/meta/internal/mtags/SymbolIndexBucket.scala

@@ -223,8 +223,7 @@ class SymbolIndexBucket(
     }
     if (!definitions.contains(symbol.value)) {
       // Fallback 3: guess related symbols from the enclosing class.
-      DefinitionAlternatives(symbol)
-        .flatMap(alternative => query0(querySymbol, alternative))
+      DefinitionAlternatives(symbol).flatMap(query0(querySymbol, _))
     } else {
       definitions
         .get(symbol.value)

tests/cross/src/main/scala/tests/pc/BaseHoverSuite.scala

@@ -24,9 +24,11 @@ abstract class BaseHoverSuite
       expected: String,
       includeRange: Boolean = false,
       automaticPackage: Boolean = true,
-      compat: Map[String, String] = Map.empty
+      compat: Map[String, String] = Map.empty,
+      repeat: Int = 1
   )(implicit loc: Location): Unit = {
     test(testOpt) {
+      assert(repeat > 0)
       val filename = "Hover.scala"
       val pkg = scala.meta.Term.Name(testOpt.name).syntax
       val noRange = original
@@ -42,10 +44,14 @@ abstract class BaseHoverSuite
       } else {
         CompilerRangeParams(Paths.get(filename).toUri(), code, so, eo)
       }
-      val hover = presentationCompiler
-        .hover(pcParams)
-        .get()
-        .asScala
+      val hover = (0 to repeat)
+        .map(_ =>
+          presentationCompiler
+            .hover(pcParams)
+            .get()
+            .asScala
+        )
+        .last
         .map(_.toLsp())
       val obtained: String = renderAsString(code, hover, includeRange)
       assertNoDiff(

tests/cross/src/test/scala/tests/hover/HoverScala3TypeSuite.scala

@@ -595,4 +595,21 @@ class HoverScala3TypeSuite extends BaseHoverSuite {
        |""".stripMargin
   )
 
+  check(
+    "i6852",
+    """
+      |type Foo = String
+      |
+      |/** some doc */
+      |object Foo:
+      |  /** doc doc */
+      |  val fo@@o = ""
+      |""".stripMargin,
+    """|```scala
+       |val foo: String
+       |```
+       |doc doc""".stripMargin,
+    repeat = 2
+  )
+
 }

tests/cross/src/test/scala/tests/pc/SignatureHelpSuite.scala

@@ -520,7 +520,7 @@ class SignatureHelpSuite extends BaseSignatureHelpSuite {
       |
       |
     """.stripMargin,
-    """|apply(viewId: String, nodeUri: String, label: String, command: String = ..., icon: String = ..., tooltip: String = ..., collapseState: String = ...): TreeViewNode
+    """|apply(viewId: String, nodeUri: String, label: String, command: String = null, icon: String = null, tooltip: String = null, collapseState: String = null): TreeViewNode
        |      ^^^^^^^^^^^^^^
        |""".stripMargin,
     compat = Map(