Test that product{Arity, Element} are synthesised on demend

Author: OlivierBlanvillain

tests/run/i2314.scala

@@ -0,0 +1,37 @@
+case class A(i: Int, s: String)
+
+case class B(i: Int, s: String) {
+  // No override, these methods will be added by SyntheticMethods only if
+  // there are not user defined.
+  def productArity = -1
+  def productElement(i: Int): Any = None
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val a = A(1, "s")
+    assert(a.productArity == 2)
+    assert(a.productElement(0) == 1)
+    assert(a.productElement(1) == "s")
+
+    try {
+      a.productElement(-1)
+      ???
+    } catch {
+      case e: IndexOutOfBoundsException =>
+        assert(e.getMessage == "-1")
+    }
+    try {
+      a.productElement(2)
+      ???
+    } catch {
+      case e: IndexOutOfBoundsException =>
+        assert(e.getMessage == "2")
+    }
+
+    val b = B(1, "s")
+    assert(b.productArity == -1)
+    assert(b.productElement(0) == None)
+    assert(b.productElement(1) == None)
+  }
+}