Migrated test block 216 to Dart 2.0.

tests/lib/math/random_test.dart

-// Copyright (c) 2013, 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 rnd.nextInt with a seed generates the same sequence each time.
-
-// Library tag to allow Dartium to run the test.
-library random_test;
-
-import "package:expect/expect.dart";
-import 'dart:math';
-
-main() {
-  checkSequence();
-  checkSeed();
-}
-
-void checkSequence() {
-  // Check the sequence of numbers generated by the random generator for a seed
-  // doesn't change unintendedly, and it agrees between implementations.
-  var rnd = new Random(20130307);
-  // Make sure we do not break the random number generation.
-  // If the random algorithm changes, make sure both the VM and dart2js
-  // generate the same new sequence.
-  var i = 1;
-  Expect.equals(0, rnd.nextInt(i *= 2));
-  Expect.equals(3, rnd.nextInt(i *= 2));
-  Expect.equals(7, rnd.nextInt(i *= 2));
-  Expect.equals(5, rnd.nextInt(i *= 2));
-  Expect.equals(29, rnd.nextInt(i *= 2));
-  Expect.equals(17, rnd.nextInt(i *= 2));
-  Expect.equals(104, rnd.nextInt(i *= 2));
-  Expect.equals(199, rnd.nextInt(i *= 2));
-  Expect.equals(408, rnd.nextInt(i *= 2));
-  Expect.equals(362, rnd.nextInt(i *= 2));
-  Expect.equals(995, rnd.nextInt(i *= 2));
-  Expect.equals(2561, rnd.nextInt(i *= 2));
-  Expect.equals(2548, rnd.nextInt(i *= 2));
-  Expect.equals(9553, rnd.nextInt(i *= 2));
-  Expect.equals(2628, rnd.nextInt(i *= 2));
-  Expect.equals(42376, rnd.nextInt(i *= 2));
-  Expect.equals(101848, rnd.nextInt(i *= 2));
-  Expect.equals(85153, rnd.nextInt(i *= 2));
-  Expect.equals(495595, rnd.nextInt(i *= 2));
-  Expect.equals(647122, rnd.nextInt(i *= 2));
-  Expect.equals(793546, rnd.nextInt(i *= 2));
-  Expect.equals(1073343, rnd.nextInt(i *= 2));
-  Expect.equals(4479969, rnd.nextInt(i *= 2));
-  Expect.equals(9680425, rnd.nextInt(i *= 2));
-  Expect.equals(28460171, rnd.nextInt(i *= 2));
-  Expect.equals(49481738, rnd.nextInt(i *= 2));
-  Expect.equals(9878974, rnd.nextInt(i *= 2));
-  Expect.equals(132552472, rnd.nextInt(i *= 2));
-  Expect.equals(210267283, rnd.nextInt(i *= 2));
-  Expect.equals(125422442, rnd.nextInt(i *= 2));
-  Expect.equals(226275094, rnd.nextInt(i *= 2));
-  Expect.equals(1639629168, rnd.nextInt(i *= 2));
-  Expect.equals(0x100000000, i);
-  // If max is too large expect an ArgumentError.
-  Expect.throws(() => rnd.nextInt(i + 1), (e) => e is ArgumentError);
-
-  rnd = new Random(6790);
-  Expect.approxEquals(0.1202733131, rnd.nextDouble());
-  Expect.approxEquals(0.5554054805, rnd.nextDouble());
-  Expect.approxEquals(0.0385160727, rnd.nextDouble());
-  Expect.approxEquals(0.2836345217, rnd.nextDouble());
-}
-
-void checkSeed() {
-  // Check that various seeds generate the expected first values.
-  // 53 significant bits, so the number is representable in JS.
-  var rawSeed = 0x19a32c640e1d71;
-  var expectations = [
-    26007,
-    43006,
-    46458,
-    18610,
-    16413,
-    50455,
-    2164,
-    47399,
-    8859,
-    9732,
-    20367,
-    33935,
-    54549,
-    54913,
-    4819,
-    24198,
-    49353,
-    22277,
-    51852,
-    35959,
-    45347,
-    12100,
-    10136,
-    22372,
-    15293,
-    20066,
-    1351,
-    49030,
-    64845,
-    12793,
-    50916,
-    55784,
-    43170,
-    27653,
-    34696,
-    1492,
-    50255,
-    9597,
-    45929,
-    2874,
-    27629,
-    53084,
-    36064,
-    42140,
-    32016,
-    41751,
-    13967,
-    20516,
-    578,
-    16773,
-    53064,
-    14814,
-    22737,
-    48846,
-    45147,
-    10205,
-    56584,
-    63711,
-    44128,
-    21099,
-    47966,
-    35471,
-    39576,
-    1141,
-    45716,
-    54940,
-    57406,
-    15437,
-    31721,
-    35044,
-    28136,
-    39797,
-    50801,
-    22184,
-    58686
-  ];
-  var negative_seed_expectations = [
-    12170,
-    42844,
-    39228,
-    64032,
-    29046,
-    57572,
-    8453,
-    52224,
-    27060,
-    28454,
-    20510,
-    28804,
-    59221,
-    53422,
-    11047,
-    50864,
-    33997,
-    19611,
-    1250,
-    65088,
-    19690,
-    11396,
-    20,
-    48867,
-    44862,
-    47129,
-    58724,
-    13325,
-    50005,
-    33320,
-    16523,
-    4740,
-    63721,
-    63272,
-    30545,
-    51403,
-    35845,
-    3943,
-    31850,
-    23148,
-    26307,
-    1724,
-    29281,
-    39988,
-    43653,
-    48012,
-    43810,
-    16755,
-    13105,
-    25325,
-    32648,
-    19958,
-    38838,
-    8322,
-    3421,
-    28624,
-    17269,
-    45385,
-    50680,
-    1696,
-    26088,
-    2787,
-    48566,
-    34357,
-    27731,
-    51764,
-    8455,
-    16498,
-    59721,
-    59568,
-    46333,
-    7935,
-    51459,
-    36766,
-    50711
-  ];
-  for (var i = 0, m = 1; i < 75; i++) {
-    Expect.equals(expectations[i], new Random(rawSeed * m).nextInt(65536));
-    Expect.equals(
-        negative_seed_expectations[i], new Random(rawSeed * -m).nextInt(65536));
-    m *= 2;
-  }
-  // And test zero seed too.
-  Expect.equals(21391, new Random(0).nextInt(65536));
-}