SI-4691 exhaustivity: `unapply: Some` = irrefutable

overhauls treeMakersToConds in the process -- was getting a bit unwieldy

1 files changed, 33 insertions, 0 deletions

diff --git a/test/files/neg/t4691_exhaust_extractor.scala b/test/files/neg/t4691_exhaust_extractor.scala
new file mode 100644
index 0000000000..c68c33d654
--- /dev/null
+++ b/test/files/neg/t4691_exhaust_extractor.scala
@@ -0,0 +1,33 @@
+sealed trait Foo
+class Bar1 extends Foo
+class Bar2 extends Foo
+class Bar3 extends Foo
+
+// these extractors are known to always succeed as they return a Some
+object Baz1 {
+  def unapply(x: Bar1): Some[Int] = Some(1)
+}
+object Baz2 {
+  def unapply(x: Bar2): Some[Int] = Some(2)
+}
+
+
+object Test {
+  // warning: missing Bar3
+  def f1(x: Foo) = x match {
+    case _: Bar1 => 1
+    case _: Bar2 => 2
+  }
+
+  // warning: missing Bar3
+  def f2(x: Foo) = x match {
+    case _: Bar1 => 1
+    case Baz2(x) => x
+  }
+
+  // warning: missing Bar3
+  def f3(x: Foo) = x match {
+    case Baz1(x) => x
+    case Baz2(x) => x
+  }
+}
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