Merge pull request #3124 from DarkDimius/fix-7443

 Fix SI-7443 Range.sum ignoring Numeric argument and always assuming default 'plus' implementation

1 files changed, 41 insertions, 0 deletions

diff --git a/test/files/scalacheck/range.scala b/test/files/scalacheck/range.scala
index 6c7c32bfdf..1eb186f303 100644
--- a/test/files/scalacheck/range.scala
+++ b/test/files/scalacheck/range.scala
@@ -127,6 +127,47 @@ abstract class RangeTest(kind: String) extends Properties("Range "+kind) {
     (visited == expectedSize(r)) :| str(r)
   }
 
+  property("sum") = forAll(myGen) { r =>
+//    println("----------")
+//    println("sum "+str(r))
+    val rSum = r.sum
+    val expected = r.length match {
+      case 0 => 0
+      case 1 => r.head
+      case _ => ((r.head + r.last).toLong * r.length  / 2).toInt
+    }
+//   println("size: " + r.length)
+//   println("expected: " + expected)
+//   println("obtained: " + rSum)
+
+   (rSum == expected) :| str(r)
+  }
+
+/* checks that sum respects custom Numeric */
+  property("sumCustomNumeric") = forAll(myGen) { r =>
+    val mod = 65536
+    object mynum extends Numeric[Int] {
+        def plus(x: Int, y: Int): Int = (x + y) % mod
+        override def zero = 0
+
+        def fromInt(x: Int): Int = ???
+        def minus(x: Int, y: Int): Int = ???
+        def negate(x: Int): Int = ???
+        def times(x: Int, y: Int): Int = ???
+        def toDouble(x: Int): Double = ???
+        def toFloat(x: Int): Float = ???
+        def toInt(x: Int): Int = ((x % mod) + mod * 2) % mod
+        def toLong(x: Int): Long = ???
+        def compare(x: Int, y: Int): Int = ???
+      }
+
+    val rSum = r.sum(mynum)
+    val expected = mynum.toInt(r.sum)
+
+    (rSum == expected) :| str(r)
+  }
+
+
   property("length") = forAll(myGen suchThat (r => expectedSize(r).toInt == expectedSize(r))) { r =>
 //    println("length "+str(r))
     (r.length == expectedSize(r)) :| str(r)