enhance FinalCaseClasses rule to allow sealed case classes and add corresponding tests

Author: halotukozak

analyzer/src/main/scala/com/avsystem/commons/analyzer/FinalCaseClasses.scala

@@ -10,9 +10,8 @@ class FinalCaseClasses(g: Global) extends AnalyzerRule(g, "finalCaseClasses", Le
   import global.*
 
   def analyze(unit: CompilationUnit): Unit = unit.body.foreach {
-    case cd: ClassDef if !cd.mods.hasFlag(Flag.FINAL) && cd.mods.hasFlag(Flag.CASE) =>
+    case cd: ClassDef if !cd.mods.hasFlag(Flag.FINAL | Flag.SEALED) && cd.mods.hasFlag(Flag.CASE) =>
       // Skip case classes defined inside traits (SI-4440)
-
       val isInner = cd.symbol.isStatic
 
       if (isInner) {

analyzer/src/test/scala/com/avsystem/commons/analyzer/FinalCaseClassesTest.scala

@@ -38,7 +38,7 @@ class FinalCaseClassesTest extends AnyFunSuite with AnalyzerTest {
   }
 
   // SI-4440 https://github.com/scala/bug/issues/4440
-  test("should not be affected due to SI-4440"){
+  test("should not be affected due to SI-4440") {
     assertNoErrors(
       //language=scala
       """
@@ -56,4 +56,19 @@ class FinalCaseClassesTest extends AnyFunSuite with AnalyzerTest {
         """.stripMargin
     )
   }
+
+  test("sealed case class should not be affected") {
+    assertNoErrors(
+      //language=scala
+      """
+        |sealed case class SealedCaseClass(x: Int) {
+        |  def double: Int = x * 2
+        |}
+        |object SealedCaseClass {
+        |  val jeden = SealedCaseClass(1)
+        |  val dwa = SealedCaseClass(2)
+        |}
+  """.stripMargin
+    )
+  }
 }