1 files changed, 70 insertions, 0 deletions
diff --git a/test/junit/scala/tools/nsc/symtab/CannotHaveAttrsTest.scala b/test/junit/scala/tools/nsc/symtab/CannotHaveAttrsTest.scala
new file mode 100644
index 0000000000..5867a9030b
--- /dev/null
+++ b/test/junit/scala/tools/nsc/symtab/CannotHaveAttrsTest.scala
@@ -0,0 +1,70 @@
+package scala.tools.nsc
+package symtab
+
+import org.junit.Assert._
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+import scala.tools.testing.AssertUtil.assertThrows
+import scala.reflect.internal.util.OffsetPosition
+
+@RunWith(classOf[JUnit4])
+class CannotHaveAttrsTest {
+  class CustomSymbolTable extends SymbolTableForUnitTesting {
+    object CHA extends CannotHaveAttrs {
+      def canEqual(that: Any): Boolean = ???
+      def productArity: Int = ???
+      def productElement(n: Int): Any = ???
+    }
+    val attrlessTrees = List(CHA, EmptyTree, emptyValDef, pendingSuperCall)
+  }
+  def withCtx(body: CustomSymbolTable => Unit) = body(new CustomSymbolTable)
+
+  @Test
+  def canHaveAttrsIsFalse = withCtx { st => import st._
+    attrlessTrees.foreach { t =>
+      assertFalse(t.canHaveAttrs)
+    }
+  }
+
+  @Test
+  def defaultPosAssignment = withCtx { st => import st._
+    attrlessTrees.foreach { t =>
+      assertEquals(t.pos, NoPosition)
+      t.pos = NoPosition
+      assertEquals(t.pos, NoPosition)
+      t.setPos(NoPosition)
+      assertEquals(t.pos, NoPosition)
+    }
+  }
+
+  @Test
+  def defaultTpeAssignment = withCtx { st => import st._
+    attrlessTrees.foreach { t =>
+      assertEquals(t.tpe, NoType)
+      t.tpe = NoType
+      assertEquals(t.tpe, NoType)
+      t.setType(NoType)
+      assertEquals(t.tpe, NoType)
+    }
+  }
+
+  @Test
+  def nonDefaultPosAssignmentFails = withCtx { st => import st._
+    val pos = new OffsetPosition(null, 0)
+    attrlessTrees.foreach { t =>
+      assertThrows[IllegalArgumentException] { t.pos = pos }
+      assertThrows[IllegalArgumentException] { t.setPos(pos) }
+    }
+  }
+
+  @Test
+  def nonDefaultTpeAssignmentFails = withCtx { st => import st._
+    val tpe = typeOf[Int]
+    attrlessTrees.foreach { t =>
+      assertThrows[IllegalArgumentException] { t.tpe = tpe }
+      assertThrows[IllegalArgumentException] { t.setType(tpe) }
+    }
+  }
+}