From f1b769c2f65df7b41a986d0618657cdf69d5b89b Mon Sep 17 00:00:00 2001
From: Katarzyna Marek <kasia@marek.net>
Date: Fri, 6 Oct 2023 16:49:59 +0200
Subject: [PATCH] add tests and fix `case` case

---
 .../pc/completions/MatchCaseCompletions.scala | 12 ++--
 .../scala/tests/pc/CompletionCaseSuite.scala  | 47 +++++++++++++++
 .../scala/tests/pc/CompletionMatchSuite.scala | 60 ++++++++++++++++---
 3 files changed, 106 insertions(+), 13 deletions(-)

diff --git a/mtags/src/main/scala-3/scala/meta/internal/pc/completions/MatchCaseCompletions.scala b/mtags/src/main/scala-3/scala/meta/internal/pc/completions/MatchCaseCompletions.scala
index e256a137618..1b349b57f09 100644
--- a/mtags/src/main/scala-3/scala/meta/internal/pc/completions/MatchCaseCompletions.scala
+++ b/mtags/src/main/scala-3/scala/meta/internal/pc/completions/MatchCaseCompletions.scala
@@ -87,7 +87,7 @@ object CaseKeywordCompletion:
             new Parents(NoType, definitions)
       case sel => new Parents(sel.tpe, definitions)
 
-    val selectorSym = parents.selector.metalsDealias.typeSymbol
+    val selectorSym = parents.selector.widen.metalsDealias.typeSymbol
 
     // Special handle case when selector is a tuple or `FunctionN`.
     if definitions.isTupleClass(selectorSym) || definitions.isFunctionClass(
@@ -150,7 +150,9 @@ object CaseKeywordCompletion:
           if isValid(ts) then visit(autoImportsGen.inferSymbolImport(ts))
         )
       // Step 2: walk through known subclasses of sealed types.
-      val sealedDescs = subclassesForType(parents.selector.widen.bounds.hi)
+      val sealedDescs = subclassesForType(
+        parents.selector.widen.metalsDealias.bounds.hi
+      )
       sealedDescs.foreach { sym =>
         val symbolImport = autoImportsGen.inferSymbolImport(sym)
         visit(symbolImport)
@@ -238,9 +240,9 @@ object CaseKeywordCompletion:
       completionPos,
       clientSupportsSnippets,
     )
-    val tpe = selector.tpe.widen.bounds.hi match
-      case tr @ TypeRef(_, _) => tr.underlying.metalsDealias
-      case t => t.metalsDealias
+    val tpe = selector.tpe.widen.metalsDealias.bounds.hi match
+      case tr @ TypeRef(_, _) => tr.underlying
+      case t => t
 
     val sortedSubclasses =
       val subclasses =
diff --git a/tests/cross/src/test/scala/tests/pc/CompletionCaseSuite.scala b/tests/cross/src/test/scala/tests/pc/CompletionCaseSuite.scala
index be33b8027ea..43c32b3cab0 100644
--- a/tests/cross/src/test/scala/tests/pc/CompletionCaseSuite.scala
+++ b/tests/cross/src/test/scala/tests/pc/CompletionCaseSuite.scala
@@ -693,4 +693,51 @@ class CompletionCaseSuite extends BaseCompletionSuite {
        |case Sports(time, intensity) => exhaustive-enum-tags3.Activity""".stripMargin,
   )
 
+  check(
+    "type-alias-case".tag(IgnoreScala2),
+    s"""|object O:
+        |  type Id[A] = A
+        |
+        |  enum Animal:
+        |    case Cat, Dog
+        | 
+        |  val animal: Id[Animal] = ???
+        |
+        |  animal match
+        |    cas@@
+        |""".stripMargin,
+    """|case Animal.Cat =>
+       |case Animal.Dog =>
+       |""".stripMargin,
+  )
+
+  check(
+    "type-alias-sealed-trait-case",
+    s"""|object O {
+        | type Id[A] = A
+        |
+        |sealed trait Animal
+        |object Animal {
+        |   case class Cat() extends Animal
+        |   case object Dog extends Animal
+        |}
+        | 
+        | val animal: Id[Animal] = ???
+        |
+        |  animal match {
+        |    cas@@
+        |  }
+        |}
+        |""".stripMargin,
+    """|case Cat() => `type-alias-sealed-trait-case`.O.Animal
+       |case Dog => `type-alias-sealed-trait-case`.O.Animal
+       |""".stripMargin,
+    compat = Map(
+      "3" ->
+        """|case Cat() => type-alias-sealed-trait-case.O.Animal
+           |case Dog => type-alias-sealed-trait-case.O.Animal
+           |""".stripMargin
+    ),
+  )
+
 }
diff --git a/tests/cross/src/test/scala/tests/pc/CompletionMatchSuite.scala b/tests/cross/src/test/scala/tests/pc/CompletionMatchSuite.scala
index 3ff6f65ac1b..9246d220d6b 100644
--- a/tests/cross/src/test/scala/tests/pc/CompletionMatchSuite.scala
+++ b/tests/cross/src/test/scala/tests/pc/CompletionMatchSuite.scala
@@ -764,22 +764,66 @@ class CompletionMatchSuite extends BaseCompletionSuite {
     filter = _.contains("exhaustive"),
   )
 
-  check(
-    "type-alias2".tag(IgnoreScala2),
+  checkEdit(
+    "type-alias-sealed-trait",
     s"""|object O {
         | type Id[A] = A
         |
-        | enum Animal:
-        |   case Cat, Dog
+        |sealed trait Animal
+        |object Animal {
+        |   case object Cat extends Animal
+        |   case object Dog extends Animal
+        |}
         | 
         | val animal: Id[Animal] = ???
         |
-        |  animal match {
-        |  \tcase Animal.C@@
-        |  }
+        |animal ma@@
         |}
         |""".stripMargin,
-    "Cat: Animal",
+    s"""
+       |import O.Animal.Cat
+       |import O.Animal.Dog
+       |object O {
+       | type Id[A] = A
+       |
+       |sealed trait Animal
+       |object Animal {
+       |   case object Cat extends Animal
+       |   case object Dog extends Animal
+       |}
+       | 
+       | val animal: Id[Animal] = ???
+       |
+       |animal match {
+       |\tcase Cat => $$0
+       |\tcase Dog =>
+       |}
+       |}
+       |""".stripMargin,
+    compat = Map(
+      "3" ->
+        s"""
+           |import O.Animal.Cat
+           |import O.Animal.Dog
+           |object O {
+           | type Id[A] = A
+           |
+           |sealed trait Animal
+           |object Animal {
+           |   case object Cat extends Animal
+           |   case object Dog extends Animal
+           |}
+           | 
+           | val animal: Id[Animal] = ???
+           |
+           |animal match
+           |\tcase Cat => $$0
+           |\tcase Dog =>
+           |
+           |}
+           |""".stripMargin
+    ),
+    filter = _.contains("exhaustive"),
   )
 
 }