update dart:math

test/codegen/lib/math/coin_test.dart

Index: test/codegen/lib/math/coin_test.dart
diff --git a/test/codegen/lib/math/coin_test.dart b/test/codegen/lib/math/coin_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..1ca2261884fd525e58183128752a0d8ea956c25d
--- /dev/null
+++ b/test/codegen/lib/math/coin_test.dart
@@ -0,0 +1,62 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Test that a coin toss with Random.nextBool() is fair.
+
+// Library tag to allow Dartium to run the test.
+library coin_test;
+
+import "package:expect/expect.dart";
+import 'dart:math';
+
+main() {
+  var seed = new Random().nextInt(1<<16);
+  print("coin_test seed: $seed");
+  var rnd = new Random(seed);
+  var heads = 0;
+  var tails = 0;
+  for (var i = 0; i < 10000; i++) {
+    if (rnd.nextBool()) {
+      heads++;
+    } else {
+      tails++;
+    }
+  }
+  print("Heads: $heads\n"
+        "Tails: $tails\n"
+        "Ratio: ${heads/tails}\n");
+  Expect.approxEquals(1.0, heads/tails, 0.1);
+
+  heads = 0;
+  tails = 0;
+  for (var i = 0; i < 10000; i++) {
+    rnd = new Random(i);
+    if (rnd.nextBool()) {
+      heads++;
+    } else {
+      tails++;
+    }
+  }
+  print("Heads: $heads\n"
+        "Tails: $tails\n"
+        "Ratio: ${heads/tails}\n");
+  Expect.approxEquals(1.0, heads/tails, 0.1);
+
+  // A sequence of newly allocated Random number generators should have fair
+  // initial tosses.
+  heads = 0;
+  tails = 0;
+  for (var i = 0; i < 10000; i++) {
+    rnd = new Random();
+    if (rnd.nextBool()) {
+      heads++;
+    } else {
+      tails++;
+    }
+  }
+  print("Heads: $heads\n"
+        "Tails: $tails\n"
+        "Ratio: ${heads/tails}\n");
+  Expect.approxEquals(1.0, heads/tails, 0.1);
+}