Merge pull request #2517 from dotty-staging/fix/value-class-var

Fix error message for value class with var parameter

Author: felixmulder

compiler/src/dotty/tools/dotc/typer/Checking.scala

@@ -459,7 +459,9 @@ object Checking {
       if (isCyclic(clazz.asClass))
         ctx.error(ValueClassesMayNotWrapItself(clazz), clazz.pos)
       else {
-        val clParamAccessors = clazz.asClass.paramAccessors.filter(_.isTerm)
+        val clParamAccessors = clazz.asClass.paramAccessors.filter { param =>
+          param.isTerm && !param.is(Flags.Accessor)
+        }
         clParamAccessors match {
           case List(param) =>
             if (param.is(Mutable))

compiler/test/dotty/tools/dotc/reporting/ErrorMessagesTests.scala

@@ -7,7 +7,7 @@ import diagnostic.messages._
 import dotty.tools.dotc.core.Types.WildcardType
 import dotty.tools.dotc.parsing.Tokens
 import org.junit.Assert._
-import org.junit.{Ignore, Test}
+import org.junit.Test
 
 class ErrorMessagesTests extends ErrorMessagesTest {
   // In the case where there are no errors, we can do "expectNoErrors" in the
@@ -758,7 +758,7 @@ class ErrorMessagesTests extends ErrorMessagesTest {
         assertEquals("class MyValue", valueClass.show)
       }
 
-  @Test @Ignore def valueClassParameterMayNotBeVar =
+  @Test def valueClassParameterMayNotBeVar =
     checkMessagesAfter("refchecks") {
       """class MyValue(var i: Int) extends AnyVal"""
     }