Merge pull request #4216 from som-snytt/issue/7623

SI-7623 Trailing sequence wildcard warning

3 files changed, 60 insertions, 0 deletions

diff --git a/test/files/neg/t7623.check b/test/files/neg/t7623.check
new file mode 100644
index 0000000000..db368dd369
--- /dev/null
+++ b/test/files/neg/t7623.check
@@ -0,0 +1,21 @@
+t7623.scala:19: warning: A repeated case parameter or extracted sequence should be matched only by a sequence wildcard (_*).
+  def f = "" match { case X(s) => }
+                          ^
+t7623.scala:21: warning: A repeated case parameter or extracted sequence should be matched only by a sequence wildcard (_*).
+  def g = "" match { case X(s, t) => }
+                          ^
+t7623.scala:23: warning: A repeated case parameter or extracted sequence should be matched only by a sequence wildcard (_*).
+  def h = "" match { case X(s, t, u @ _*) => }
+                          ^
+t7623.scala:9: warning: A repeated case parameter or extracted sequence should be matched only by a sequence wildcard (_*).
+  def f = C("") match { case C(s) => }
+                             ^
+t7623.scala:11: warning: A repeated case parameter or extracted sequence should be matched only by a sequence wildcard (_*).
+  def g = C("") match { case C(s, t) => }
+                             ^
+t7623.scala:13: warning: A repeated case parameter or extracted sequence should be matched only by a sequence wildcard (_*).
+  def h = C("") match { case C(s, t, u @ _*) => }
+                             ^
+error: No warnings can be incurred under -Xfatal-warnings.
+6 warnings found
+one error found
diff --git a/test/files/neg/t7623.flags b/test/files/neg/t7623.flags
new file mode 100644
index 0000000000..74c9e38323
--- /dev/null
+++ b/test/files/neg/t7623.flags
@@ -0,0 +1 @@
+-Xlint:stars-align -Xfatal-warnings
diff --git a/test/files/neg/t7623.scala b/test/files/neg/t7623.scala
new file mode 100644
index 0000000000..5c40f37bc1
--- /dev/null
+++ b/test/files/neg/t7623.scala
@@ -0,0 +1,38 @@
+
+
+case class C(s: String, xs: Int*)
+
+object X { def unapplySeq(a: Any): Option[(String, Seq[Int])] = Some("", List(1,2,3)) }
+
+// for case classes with varargs, avoid misaligned patterns
+trait Ctest {
+  def f = C("") match { case C(s) => }
+
+  def g = C("") match { case C(s, t) => }
+
+  def h = C("") match { case C(s, t, u @ _*) => }
+
+  def ok = C("") match { case C(s, u @ _*) => }
+}
+// for extractors that unapplySeq: Option[(Something, Seq[_])], avoid misaligned patterns
+trait Xtest {
+  def f = "" match { case X(s) => }
+
+  def g = "" match { case X(s, t) => }
+
+  def h = "" match { case X(s, t, u @ _*) => }
+
+  def ok = "" match { case X(s, u @ _*) => }
+}
+// for extractors that unapplySeq: Option[Seq[_]], anything goes
+trait Rtest {
+  val r = "(a+)".r
+
+  def f = "" match { case r(s) => }
+
+  def g = "" match { case r(s, t) => }
+
+  def h = "" match { case r(s, t, u @ _*) => }
+
+  def whatever = "" match { case r(u @ _*) => }
+}