Merge pull request #4115 from retronym/ticket/8597

SI-8597 Improved pattern unchecked warnings

1 files changed, 27 insertions, 0 deletions

diff --git a/test/files/neg/t8597.scala b/test/files/neg/t8597.scala
new file mode 100644
index 0000000000..068e87d91a
--- /dev/null
+++ b/test/files/neg/t8597.scala
@@ -0,0 +1,27 @@
+class Unchecked[C] {
+  def nowarn[T] = (null: Any) match { case _: Some[T]      => } // warn (did not warn due to SI-8597)
+
+  // These warned before.
+  def warn1[T]  = (null: Any) match { case _: T            => } // warn
+  def warn2     = (null: Any) match { case _: Some[String] => } // warn
+                  (null: Any) match { case _: Some[C]      => } // warn
+
+  // These must remain without warnings. These are excerpts from
+  // related tests that are more exhauative.
+  class C; class D extends C
+  def okay      = (List(new D) : Seq[D]) match { case _: List[C] => case _ => } // nowarn
+  class B2[A, B]
+  class A2[X] extends B2[X, String]
+  def okay2(x: A2[Int]) = x match { case _: B2[Int, _] => true } // nowarn
+  def okay3(x: A2[Int]) = x match { case _: B2[Int, typeVar] => true } // nowarn
+
+  def warnArray[T] = (null: Any) match { case _: Array[T] => } // warn (did not warn due to SI-8597)
+  def nowarnArrayC   = (null: Any) match { case _: Array[C] => } // nowarn
+
+  def nowarnArrayTypeVar[T] = (null: Any) match { case _: Array[t] => } // nowarn
+
+  def noWarnArrayErasure1 = (null: Any) match {case Some(_: Array[String]) => } // nowarn
+  def noWarnArrayErasure2 = (null: Any) match {case Some(_: Array[List[_]]) => } // nowarn
+  def noWarnArrayErasure3 = (null: Any) match {case Some(_: Array[Array[List[_]]]) => } // nowarn
+  def warnArrayErasure2   = (null: Any) match {case Some(_: Array[Array[List[String]]]) => } // warn
+}