Merge pull request #2439 from retronym/ticket/7369

SI-7369 Avoid spurious unreachable warnings in patterns

5 files changed, 95 insertions, 0 deletions

diff --git a/test/files/neg/t7369.check b/test/files/neg/t7369.check
new file mode 100644
index 0000000000..4f101e145a
--- /dev/null
+++ b/test/files/neg/t7369.check
@@ -0,0 +1,13 @@
+t7369.scala:6: error: unreachable code
+    case Tuple1(X) => // unreachable
+                   ^
+t7369.scala:13: error: unreachable code
+    case Tuple1(true) => // unreachable
+                      ^
+t7369.scala:31: error: unreachable code
+    case Tuple1(X) => // unreachable
+                   ^
+t7369.scala:40: error: unreachable code
+    case Tuple1(null) => // unreachable
+                      ^
+four errors found
diff --git a/test/files/neg/t7369.flags b/test/files/neg/t7369.flags
new file mode 100644
index 0000000000..e8fb65d50c
--- /dev/null
+++ b/test/files/neg/t7369.flags
@@ -0,0 +1 @@
+-Xfatal-warnings
\ No newline at end of file
diff --git a/test/files/neg/t7369.scala b/test/files/neg/t7369.scala
new file mode 100644
index 0000000000..87ddfe98b7
--- /dev/null
+++ b/test/files/neg/t7369.scala
@@ -0,0 +1,43 @@
+object Test {
+  val X, Y = true
+  (null: Tuple1[Boolean]) match {
+    case Tuple1(X) =>
+    case Tuple1(Y) =>
+    case Tuple1(X) => // unreachable
+    case _      =>
+  }
+
+  (null: Tuple1[Boolean]) match {
+    case Tuple1(true) =>
+    case Tuple1(false) =>
+    case Tuple1(true) => // unreachable
+    case _      =>
+  }
+}
+
+
+sealed abstract class B;
+case object True extends B;
+case object False extends B;
+
+object Test2 {
+
+  val X: B = True
+  val Y: B = False
+
+  (null: Tuple1[B]) match {
+    case Tuple1(X) =>
+    case Tuple1(Y) =>
+    case Tuple1(X) => // unreachable
+    case _      =>
+  }
+}
+
+object Test3 {
+  (null: Tuple1[B]) match {
+    case Tuple1(null) =>
+    case Tuple1(True) =>
+    case Tuple1(null) => // unreachable
+    case _      =>
+  }
+}
diff --git a/test/files/pos/t7369.flags b/test/files/pos/t7369.flags
new file mode 100644
index 0000000000..85d8eb2ba2
--- /dev/null
+++ b/test/files/pos/t7369.flags
@@ -0,0 +1 @@
+-Xfatal-warnings
diff --git a/test/files/pos/t7369.scala b/test/files/pos/t7369.scala
new file mode 100644
index 0000000000..2f31c93d29
--- /dev/null
+++ b/test/files/pos/t7369.scala
@@ -0,0 +1,37 @@
+object Test {
+  val X, Y = true
+  (null: Tuple1[Boolean]) match {
+    case Tuple1(X) =>
+    case Tuple1(Y) => // unreachable
+    case _      =>
+  }
+}
+
+
+sealed abstract class B;
+case object True extends B;
+case object False extends B;
+
+object Test2 {
+
+  val X: B = True
+  val Y: B = False
+
+  (null: Tuple1[B]) match {
+    case Tuple1(X) =>
+    case Tuple1(Y) => // no warning
+    case _      =>
+  }
+}
+
+object Test3 {
+  val X, O = true
+  def classify(neighbourhood: (Boolean, Boolean, Boolean)): String = {
+    neighbourhood match {
+      case (X, X, X) => "middle"
+      case (X, X, O) => "right"
+      case (O, X, X) => "left"
+      case _ => throw new IllegalArgumentException("Invalid")
+    }
+  }
+}
\ No newline at end of file