bugfix: completions for type companion object

scalameta · Jun 30, 2023 · bd6f879 · bd6f879
1 parent fc87ff0
commit bd6f879
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Showing 4 changed files with 80 additions and 4 deletions.
diff --git a/mtags/src/main/scala-3/scala/meta/internal/pc/SemanticdbSymbols.scala b/mtags/src/main/scala-3/scala/meta/internal/pc/SemanticdbSymbols.scala
@@ -2,6 +2,7 @@ package scala.meta.internal.pc
 
 import scala.util.control.NonFatal
 
+import scala.meta.internal.mtags.MtagsEnrichments.decoded
 import scala.meta.internal.mtags.MtagsEnrichments.stripBackticks
 
 import dotty.tools.dotc.core.Contexts.*
@@ -49,7 +50,29 @@ object SemanticdbSymbols:
                     typeSym :: owner.info.decl(termName(value)).symbol :: Nil
                   else typeSym :: Nil
                 case Descriptor.Term(value) =>
-                  owner.info.decl(termName(value)).symbol :: Nil
+                  val outSymbol = owner.info.decl(termName(value)).symbol
+                  if outSymbol.exists
+                  then outSymbol :: Nil
+                  else if owner.is(Package)
+                  then
+                    // Fallback for type companion objects,
+                    // e.g.
+                    // ```File.scala
+                    // package a
+                    // type Cow = Int
+                    // object Cow
+                    // ```
+                    // `ScalaTopLevelMtags` emits `a/Cow.`
+                    // but the symbol we look for is `a/File$package/Cow.`
+                    // (look: tests.pc.CompletionWorkspaceSuite.type-apply)
+                    owner.info.decls
+                      .filter { s =>
+                        s.isPackageObject && s.name.decoded.endsWith("$package")
+                      }
+                      .flatMap(tryMember)
+                      .toList
+                  else Nil
+                  end if
                 case Descriptor.Package(value) =>
                   owner.info.decl(termName(value)).symbol :: Nil
                 case Descriptor.Parameter(value) =>

diff --git a/mtags/src/main/scala-3/scala/meta/internal/pc/printer/MetalsPrinter.scala b/mtags/src/main/scala-3/scala/meta/internal/pc/printer/MetalsPrinter.scala
@@ -132,11 +132,11 @@ class MetalsPrinter(
     val typeSymbol = info.typeSymbol
 
     if sym.is(Flags.Package) || sym.isClass then
-      " " + dotcPrinter.fullName(sym.owner)
+      " " + dotcPrinter.fullName(sym.effectiveOwner)
     else if sym.is(Flags.Module) || typeSymbol.is(Flags.Module) then
       if typeSymbol != NoSymbol then
-        " " + dotcPrinter.fullName(typeSymbol.owner)
-      else " " + dotcPrinter.fullName(sym.owner)
+        " " + dotcPrinter.fullName(typeSymbol.effectiveOwner)
+      else " " + dotcPrinter.fullName(sym.effectiveOwner)
     else if sym.is(Flags.Method) then
       defaultMethodSignature(sym, info, onlyMethodParams = true)
     else tpe(info)

diff --git a/tests/cross/src/test/scala/tests/pc/CompletionWorkspaceSuite.scala b/tests/cross/src/test/scala/tests/pc/CompletionWorkspaceSuite.scala
@@ -944,4 +944,36 @@ class CompletionWorkspaceSuite extends BaseCompletionSuite {
     ),
   )
 
+  check(
+    "type-apply".tag(IgnoreScala2),
+    """|package demo
+       |
+       |package other:
+       |  type MyType = Long
+       |
+       |  object MyType:
+       |    def apply(m: Long): MyType = m
+       |
+       |val j = MyTy@@
+       |""".stripMargin,
+    """|MyType(m: Long): MyType
+       |MyType - demo.other""".stripMargin,
+  )
+
+  check(
+    "type-apply2".tag(IgnoreScala2),
+    """|package demo
+       |
+       |package other:
+       |  object MyType:
+       |    def apply(m: Long): MyType = m
+       |
+       |  type MyType = Long
+       |
+       |val j = MyTy@@
+       |""".stripMargin,
+    """|MyType(m: Long): MyType
+       |MyType - demo.other""".stripMargin,
+  )
+
 }
diff --git a/tests/unit/src/test/scala/tests/ScalaToplevelSuite.scala b/tests/unit/src/test/scala/tests/ScalaToplevelSuite.scala
@@ -501,6 +501,27 @@ class ScalaToplevelSuite extends BaseSuite {
     all = true,
   )
 
+  check(
+    "companion-to-type",
+    """|package s
+       |type Cow = Long
+       |
+       |object Cow:
+       |  def apply(m: Long): Cow = m
+       |
+       |""".stripMargin,
+    // For `s/Cow.` and `s/Cow.apply().` the corresponding symbols created by the compiler
+    // will be respectively `s/Test$package/Cow.` and `s/Test$package/Cow.apply().`.
+    //
+    // It is easier to work around this inconstancy in `SemanticdbSymbols.inverseSemanticdbSymbol`
+    // than to change symbols emitted by `ScalaTopLevelMtags`,
+    // since the object could be placed before type definition.
+    List("s/", "s/Test$package.", "s/Test$package.Cow#", "s/Cow.",
+      "s/Cow.apply()."),
+    dialect = dialects.Scala3,
+    all = true,
+  )
+
   def check(
       options: TestOptions,
       code: String,