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Comparing jsr166/src/test/tck/SplittableRandomTest.java (file contents):
Revision 1.16 by jsr166, Wed Dec 31 19:05:43 2014 UTC vs.
Revision 1.23 by jsr166, Fri Oct 13 02:34:59 2017 UTC

# Line 4 | Line 4
4   * http://creativecommons.org/publicdomain/zero/1.0/
5   */
6  
7 + import java.util.Arrays;
8 + import java.util.ArrayList;
9 + import java.util.List;
10   import java.util.SplittableRandom;
11   import java.util.concurrent.atomic.AtomicInteger;
12   import java.util.concurrent.atomic.LongAdder;
13 + import java.lang.reflect.Method;
14 + import java.util.function.Predicate;
15 + import java.util.stream.Collectors;
16  
17   import junit.framework.Test;
18   import junit.framework.TestSuite;
# Line 14 | Line 20 | import junit.framework.TestSuite;
20   public class SplittableRandomTest extends JSR166TestCase {
21  
22      public static void main(String[] args) {
23 <        junit.textui.TestRunner.run(suite());
23 >        main(suite(), args);
24      }
25      public static Test suite() {
26          return new TestSuite(SplittableRandomTest.class);
# Line 160 | Line 166 | public class SplittableRandomTest extend
166       */
167      public void testNextIntBounded() {
168          SplittableRandom sr = new SplittableRandom();
169 +        for (int i = 0; i < 2; i++) assertEquals(0, sr.nextInt(1));
170          // sample bound space across prime number increments
171          for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) {
172              int f = sr.nextInt(bound);
# Line 229 | Line 236 | public class SplittableRandomTest extend
236       */
237      public void testNextLongBounded() {
238          SplittableRandom sr = new SplittableRandom();
239 +        for (int i = 0; i < 2; i++) assertEquals(0L, sr.nextLong(1L));
240          for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) {
241              long f = sr.nextLong(bound);
242              assertTrue(0 <= f && f < bound);
# Line 410 | Line 418 | public class SplittableRandomTest extend
418          for (int least = -15485867; least < MAX_INT_BOUND; least += 524959) {
419              for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 67867967) {
420                  final int lo = least, hi = bound;
421 <                r.ints(size, lo, hi).parallel().
422 <                    forEach(x -> {if (x < lo || x >= hi)
423 <                                fails.getAndIncrement(); });
421 >                r.ints(size, lo, hi).parallel().forEach(
422 >                    x -> {
423 >                        if (x < lo || x >= hi)
424 >                            fails.getAndIncrement(); });
425              }
426          }
427          assertEquals(0, fails.get());
# Line 428 | Line 437 | public class SplittableRandomTest extend
437          for (long least = -86028121; least < MAX_LONG_BOUND; least += 1982451653L) {
438              for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
439                  final long lo = least, hi = bound;
440 <                r.longs(size, lo, hi).parallel().
441 <                    forEach(x -> {if (x < lo || x >= hi)
442 <                                fails.getAndIncrement(); });
440 >                r.longs(size, lo, hi).parallel().forEach(
441 >                    x -> {
442 >                        if (x < lo || x >= hi)
443 >                            fails.getAndIncrement(); });
444              }
445          }
446          assertEquals(0, fails.get());
# Line 446 | Line 456 | public class SplittableRandomTest extend
456          for (double least = 0.00011; least < 1.0e20; least *= 9) {
457              for (double bound = least * 1.0011; bound < 1.0e20; bound *= 17) {
458                  final double lo = least, hi = bound;
459 <                r.doubles(size, lo, hi).parallel().
460 <                    forEach(x -> {if (x < lo || x >= hi)
461 <                                fails.getAndIncrement(); });
459 >                r.doubles(size, lo, hi).parallel().forEach(
460 >                    x -> {
461 >                        if (x < lo || x >= hi)
462 >                            fails.getAndIncrement(); });
463              }
464          }
465          assertEquals(0, fails.get());
# Line 520 | Line 531 | public class SplittableRandomTest extend
531          assertEquals(size, counter.sum());
532      }
533  
534 +    /**
535 +     * SplittableRandom should implement most of Random's public methods
536 +     */
537 +    public void testShouldImplementMostRandomMethods() throws Throwable {
538 +        Predicate<Method> wasForgotten = method -> {
539 +            String name = method.getName();
540 +            // some methods deliberately not implemented
541 +            if (name.equals("setSeed")) return false;
542 +            if (name.equals("nextFloat")) return false;
543 +            if (name.equals("nextGaussian")) return false;
544 +            try {
545 +                SplittableRandom.class.getMethod(
546 +                    method.getName(), method.getParameterTypes());
547 +            } catch (ReflectiveOperationException ex) {
548 +                return true;
549 +            }
550 +            return false;
551 +        };
552 +        List<Method> forgotten =
553 +            Arrays.stream(java.util.Random.class.getMethods())
554 +            .filter(wasForgotten)
555 +            .collect(Collectors.toList());
556 +        if (!forgotten.isEmpty())
557 +            throw new AssertionError("Please implement: " + forgotten);
558 +    }
559 +
560 +    /**
561 +     * Repeated calls to nextBytes produce at least values of different signs for every byte
562 +     */
563 +    public void testNextBytes() {
564 +        SplittableRandom sr = new SplittableRandom();
565 +        int n = sr.nextInt(1, 20);
566 +        byte[] bytes = new byte[n];
567 +        outer:
568 +        for (int i = 0; i < n; i++) {
569 +            for (int tries = NCALLS; tries-->0; ) {
570 +                byte before = bytes[i];
571 +                sr.nextBytes(bytes);
572 +                byte after = bytes[i];
573 +                if (after * before < 0)
574 +                    continue outer;
575 +            }
576 +            fail("not enough variation in random bytes");
577 +        }
578 +    }
579 +
580 +    /**
581 +     * Filling an empty array with random bytes succeeds without effect.
582 +     */
583 +    public void testNextBytes_emptyArray() {
584 +        new SplittableRandom().nextBytes(new byte[0]);
585 +    }
586 +
587 +    public void testNextBytes_nullArray() {
588 +        try {
589 +            new SplittableRandom().nextBytes(null);
590 +            shouldThrow();
591 +        } catch (NullPointerException success) {}
592 +    }
593 +
594   }

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