guava-tests/test/com/google/common/primitives/UnsignedBytesTest.java - platform/external/guava - Git at Google

 /*
  * Copyright (C) 2008 The Guava Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.google.common.primitives;

 import com.google.common.collect.testing.Helpers;
 import com.google.common.testing.NullPointerTester;
 import com.google.common.testing.SerializableTester;
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.List;
 import java.util.Random;
 import junit.framework.TestCase;

 /**
  * Unit test for {@link UnsignedBytes}.
  *
  * @author Kevin Bourrillion
  * @author Louis Wasserman
  */
 public class UnsignedBytesTest extends TestCase {
   private static final byte LEAST = 0;
   private static final byte GREATEST = (byte) 255;

   // Only in this class, VALUES must be strictly ascending
   private static final byte[] VALUES = {LEAST, 127, (byte) 128, (byte) 129, GREATEST};

   public void testToInt() {
     assertEquals(0, UnsignedBytes.toInt((byte) 0));
     assertEquals(1, UnsignedBytes.toInt((byte) 1));
     assertEquals(127, UnsignedBytes.toInt((byte) 127));
     assertEquals(128, UnsignedBytes.toInt((byte) -128));
     assertEquals(129, UnsignedBytes.toInt((byte) -127));
     assertEquals(255, UnsignedBytes.toInt((byte) -1));
   }

   public void testCheckedCast() {
     for (byte value : VALUES) {
       assertEquals(value, UnsignedBytes.checkedCast(UnsignedBytes.toInt(value)));
     }
     assertCastFails(256L);
     assertCastFails(-1L);
     assertCastFails(Long.MAX_VALUE);
     assertCastFails(Long.MIN_VALUE);
   }

   public void testSaturatedCast() {
     for (byte value : VALUES) {
       assertEquals(value, UnsignedBytes.saturatedCast(UnsignedBytes.toInt(value)));
     }
     assertEquals(GREATEST, UnsignedBytes.saturatedCast(256L));
     assertEquals(LEAST, UnsignedBytes.saturatedCast(-1L));
     assertEquals(GREATEST, UnsignedBytes.saturatedCast(Long.MAX_VALUE));
     assertEquals(LEAST, UnsignedBytes.saturatedCast(Long.MIN_VALUE));
   }

   private static void assertCastFails(long value) {
     try {
       UnsignedBytes.checkedCast(value);
       fail("Cast to byte should have failed: " + value);
     } catch (IllegalArgumentException ex) {
       assertTrue(
           value + " not found in exception text: " + ex.getMessage(),
           ex.getMessage().contains(String.valueOf(value)));
     }
   }

   public void testCompare() {
     // This is the only ordering for primitives that does not have a
     // corresponding Comparable wrapper in java.lang.
     for (int i = 0; i < VALUES.length; i++) {
       for (int j = 0; j < VALUES.length; j++) {
         byte x = VALUES[i];
         byte y = VALUES[j];
         // note: spec requires only that the sign is the same
         assertEquals(
             x + ", " + y,
             Math.signum(UnsignedBytes.compare(x, y)),
             Math.signum(Ints.compare(i, j)));
       }
     }
   }

   public void testMax_noArgs() {
     try {
       UnsignedBytes.max();
       fail();
     } catch (IllegalArgumentException expected) {
     }
   }

   public void testMax() {
     assertEquals(LEAST, UnsignedBytes.max(LEAST));
     assertEquals(GREATEST, UnsignedBytes.max(GREATEST));
     assertEquals(
         (byte) 255, UnsignedBytes.max((byte) 0, (byte) -128, (byte) -1, (byte) 127, (byte) 1));
   }

   public void testMin_noArgs() {
     try {
       UnsignedBytes.min();
       fail();
     } catch (IllegalArgumentException expected) {
     }
   }

   public void testMin() {
     assertEquals(LEAST, UnsignedBytes.min(LEAST));
     assertEquals(GREATEST, UnsignedBytes.min(GREATEST));
     assertEquals(
         (byte) 0, UnsignedBytes.min((byte) 0, (byte) -128, (byte) -1, (byte) 127, (byte) 1));
     assertEquals(
         (byte) 0, UnsignedBytes.min((byte) -1, (byte) 127, (byte) 1, (byte) -128, (byte) 0));
   }

   private static void assertParseFails(String value) {
     try {
       UnsignedBytes.parseUnsignedByte(value);
       fail();
     } catch (NumberFormatException expected) {
     }
   }

   private static void assertParseFails(String value, int radix) {
     try {
       UnsignedBytes.parseUnsignedByte(value, radix);
       fail();
     } catch (NumberFormatException expected) {
     }
   }

   public void testParseUnsignedByte() {
     // We can easily afford to test this exhaustively.
     for (int i = 0; i <= 0xff; i++) {
       assertEquals((byte) i, UnsignedBytes.parseUnsignedByte(Integer.toString(i)));
     }
     assertParseFails("1000");
     assertParseFails("-1");
     assertParseFails("-128");
     assertParseFails("256");
   }

   public void testMaxValue() {
     assertTrue(
         UnsignedBytes.compare(UnsignedBytes.MAX_VALUE, (byte) (UnsignedBytes.MAX_VALUE + 1)) > 0);
   }

   public void testParseUnsignedByteWithRadix() throws NumberFormatException {
     // We can easily afford to test this exhaustively.
     for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
       for (int i = 0; i <= 0xff; i++) {
         assertEquals((byte) i, UnsignedBytes.parseUnsignedByte(Integer.toString(i, radix), radix));
       }
       assertParseFails(Integer.toString(1000, radix), radix);
       assertParseFails(Integer.toString(-1, radix), radix);
       assertParseFails(Integer.toString(-128, radix), radix);
       assertParseFails(Integer.toString(256, radix), radix);
     }
   }

   public void testParseUnsignedByteThrowsExceptionForInvalidRadix() {
     // Valid radix values are Character.MIN_RADIX to Character.MAX_RADIX,
     // inclusive.
     try {
       UnsignedBytes.parseUnsignedByte("0", Character.MIN_RADIX - 1);
       fail();
     } catch (NumberFormatException expected) {
     }

     try {
       UnsignedBytes.parseUnsignedByte("0", Character.MAX_RADIX + 1);
       fail();
     } catch (NumberFormatException expected) {
     }

     // The radix is used as an array index, so try a negative value.
     try {
       UnsignedBytes.parseUnsignedByte("0", -1);
       fail();
     } catch (NumberFormatException expected) {
     }
   }

   public void testToString() {
     // We can easily afford to test this exhaustively.
     for (int i = 0; i <= 0xff; i++) {
       assertEquals(Integer.toString(i), UnsignedBytes.toString((byte) i));
     }
   }

   public void testToStringWithRadix() {
     // We can easily afford to test this exhaustively.
     for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
       for (int i = 0; i <= 0xff; i++) {
         assertEquals(Integer.toString(i, radix), UnsignedBytes.toString((byte) i, radix));
       }
     }
   }

   public void testJoin() {
     assertEquals("", UnsignedBytes.join(",", new byte[] {}));
     assertEquals("1", UnsignedBytes.join(",", new byte[] {(byte) 1}));
     assertEquals("1,2", UnsignedBytes.join(",", (byte) 1, (byte) 2));
     assertEquals("123", UnsignedBytes.join("", (byte) 1, (byte) 2, (byte) 3));
     assertEquals("128,255", UnsignedBytes.join(",", (byte) 128, (byte) -1));
   }

   private static String unsafeComparatorClassName() {
     return UnsignedBytes.LexicographicalComparatorHolder.class.getName() + "$UnsafeComparator";
   }

   private static boolean unsafeComparatorAvailable() {
     // See Java Puzzler #44
     // Use reflection instead of catching NoClassDefFoundError
     try {
       Class.forName(unsafeComparatorClassName());
       return true;
     } catch (Error | ClassNotFoundException tolerable) {
       /*
        * We're probably running on Android.
        *
        * A note on exception types:
        *
        * Android API level 10 throws ExceptionInInitializerError the first time and
        * ClassNotFoundException thereafter.
        *
        * Android API level 26 and JVM8 both let our Error propagate directly the first time and
        * throw NoClassDefFoundError thereafter. This is the proper behavior according to the spec.
        * See https://docs.oracle.com/javase/specs/jls/se8/html/jls-12.html#jls-12.4.2 (steps #11 and
        * #5).
        *
        * Note that that "first time" might happen in a test other than
        * testLexicographicalComparatorChoice!
        */
       return false;
     }
   }

   public void testLexicographicalComparatorChoice() throws Exception {
     Comparator<byte[]> defaultComparator = UnsignedBytes.lexicographicalComparator();
     assertNotNull(defaultComparator);
     assertSame(defaultComparator, UnsignedBytes.lexicographicalComparator());
     if (unsafeComparatorAvailable()) {
       assertSame(defaultComparator.getClass(), Class.forName(unsafeComparatorClassName()));
     } else {
       assertSame(defaultComparator, UnsignedBytes.lexicographicalComparatorJavaImpl());
     }
   }

   public void testLexicographicalComparator() {
     List<byte[]> ordered =
         Arrays.asList(
             new byte[] {},
             new byte[] {LEAST},
             new byte[] {LEAST, LEAST},
             new byte[] {LEAST, (byte) 1},
             new byte[] {(byte) 1},
             new byte[] {(byte) 1, LEAST},
             new byte[] {GREATEST, GREATEST - (byte) 1},
             new byte[] {GREATEST, GREATEST},
             new byte[] {GREATEST, GREATEST, GREATEST});

     // The Unsafe implementation if it's available. Otherwise, the Java implementation.
     Comparator<byte[]> comparator = UnsignedBytes.lexicographicalComparator();
     Helpers.testComparator(comparator, ordered);
     assertSame(comparator, SerializableTester.reserialize(comparator));

     // The Java implementation.
     Comparator<byte[]> javaImpl = UnsignedBytes.lexicographicalComparatorJavaImpl();
     Helpers.testComparator(javaImpl, ordered);
     assertSame(javaImpl, SerializableTester.reserialize(javaImpl));
   }

   @SuppressWarnings("unchecked")
   public void testLexicographicalComparatorLongInputs() {
     Random rnd = new Random();
     for (Comparator<byte[]> comparator :
         Arrays.asList(
             UnsignedBytes.lexicographicalComparator(),
             UnsignedBytes.lexicographicalComparatorJavaImpl())) {
       for (int trials = 10; trials-- > 0; ) {
         byte[] left = new byte[1 + rnd.nextInt(32)];
         rnd.nextBytes(left);
         byte[] right = left.clone();
         assertTrue(comparator.compare(left, right) == 0);
         int i = rnd.nextInt(left.length);
         left[i] ^= (byte) (1 + rnd.nextInt(255));
         assertTrue(comparator.compare(left, right) != 0);
         assertEquals(
             comparator.compare(left, right) > 0, UnsignedBytes.compare(left[i], right[i]) > 0);
       }
     }
   }

   public void testSort() {
     testSort(new byte[] {}, new byte[] {});
     testSort(new byte[] {2}, new byte[] {2});
     testSort(new byte[] {2, 1, 0}, new byte[] {0, 1, 2});
     testSort(new byte[] {2, GREATEST, 1, LEAST}, new byte[] {LEAST, 1, 2, GREATEST});
   }

   static void testSort(byte[] input, byte[] expected) {
     input = Arrays.copyOf(input, input.length);
     UnsignedBytes.sort(input);
     assertTrue(Arrays.equals(expected, input));
   }

   static void testSort(byte[] input, int from, int to, byte[] expected) {
     input = Arrays.copyOf(input, input.length);
     UnsignedBytes.sort(input, from, to);
     assertTrue(Arrays.equals(expected, input));
   }

   public void testSortIndexed() {
     testSort(new byte[] {}, 0, 0, new byte[] {});
     testSort(new byte[] {2}, 0, 1, new byte[] {2});
     testSort(new byte[] {2, 1, 0}, 0, 2, new byte[] {1, 2, 0});
     testSort(new byte[] {2, GREATEST, 1, LEAST}, 1, 4, new byte[] {2, LEAST, 1, GREATEST});
   }

   public void testSortDescending() {
     testSortDescending(new byte[] {}, new byte[] {});
     testSortDescending(new byte[] {1}, new byte[] {1});
     testSortDescending(new byte[] {1, 2}, new byte[] {2, 1});
     testSortDescending(new byte[] {1, 3, 1}, new byte[] {3, 1, 1});
     testSortDescending(
         new byte[] {GREATEST - 1, 1, GREATEST - 2, 2},
         new byte[] {GREATEST - 1, GREATEST - 2, 2, 1});
   }

   private static void testSortDescending(byte[] input, byte[] expectedOutput) {
     input = Arrays.copyOf(input, input.length);
     UnsignedBytes.sortDescending(input);
     assertTrue(Arrays.equals(expectedOutput, input));
   }

   private static void testSortDescending(
       byte[] input, int fromIndex, int toIndex, byte[] expectedOutput) {
     input = Arrays.copyOf(input, input.length);
     UnsignedBytes.sortDescending(input, fromIndex, toIndex);
     assertTrue(Arrays.equals(expectedOutput, input));
   }

   public void testSortDescendingIndexed() {
     testSortDescending(new byte[] {}, 0, 0, new byte[] {});
     testSortDescending(new byte[] {1}, 0, 1, new byte[] {1});
     testSortDescending(new byte[] {1, 2}, 0, 2, new byte[] {2, 1});
     testSortDescending(new byte[] {1, 3, 1}, 0, 2, new byte[] {3, 1, 1});
     testSortDescending(new byte[] {1, 3, 1}, 0, 1, new byte[] {1, 3, 1});
     testSortDescending(
         new byte[] {GREATEST - 1, 1, GREATEST - 2, 2},
         1,
         3,
         new byte[] {GREATEST - 1, GREATEST - 2, 1, 2});
   }

   public void testNulls() {
     new NullPointerTester().testAllPublicStaticMethods(UnsignedBytes.class);
   }
 }
	/*
	* Copyright (C) 2008 The Guava Authors
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.google.common.primitives;

	import com.google.common.collect.testing.Helpers;
	import com.google.common.testing.NullPointerTester;
	import com.google.common.testing.SerializableTester;
	import java.util.Arrays;
	import java.util.Comparator;
	import java.util.List;
	import java.util.Random;
	import junit.framework.TestCase;

	/**
	* Unit test for {@link UnsignedBytes}.
	*
	* @author Kevin Bourrillion
	* @author Louis Wasserman
	*/
	public class UnsignedBytesTest extends TestCase {
	private static final byte LEAST = 0;
	private static final byte GREATEST = (byte) 255;

	// Only in this class, VALUES must be strictly ascending
	private static final byte[] VALUES = {LEAST, 127, (byte) 128, (byte) 129, GREATEST};

	public void testToInt() {
	assertEquals(0, UnsignedBytes.toInt((byte) 0));
	assertEquals(1, UnsignedBytes.toInt((byte) 1));
	assertEquals(127, UnsignedBytes.toInt((byte) 127));
	assertEquals(128, UnsignedBytes.toInt((byte) -128));
	assertEquals(129, UnsignedBytes.toInt((byte) -127));
	assertEquals(255, UnsignedBytes.toInt((byte) -1));
	}

	public void testCheckedCast() {
	for (byte value : VALUES) {
	assertEquals(value, UnsignedBytes.checkedCast(UnsignedBytes.toInt(value)));
	}
	assertCastFails(256L);
	assertCastFails(-1L);
	assertCastFails(Long.MAX_VALUE);
	assertCastFails(Long.MIN_VALUE);
	}

	public void testSaturatedCast() {
	for (byte value : VALUES) {
	assertEquals(value, UnsignedBytes.saturatedCast(UnsignedBytes.toInt(value)));
	}
	assertEquals(GREATEST, UnsignedBytes.saturatedCast(256L));
	assertEquals(LEAST, UnsignedBytes.saturatedCast(-1L));
	assertEquals(GREATEST, UnsignedBytes.saturatedCast(Long.MAX_VALUE));
	assertEquals(LEAST, UnsignedBytes.saturatedCast(Long.MIN_VALUE));
	}

	private static void assertCastFails(long value) {
	try {
	UnsignedBytes.checkedCast(value);
	fail("Cast to byte should have failed: " + value);
	} catch (IllegalArgumentException ex) {
	assertTrue(
	value + " not found in exception text: " + ex.getMessage(),
	ex.getMessage().contains(String.valueOf(value)));
	}
	}

	public void testCompare() {
	// This is the only ordering for primitives that does not have a
	// corresponding Comparable wrapper in java.lang.
	for (int i = 0; i < VALUES.length; i++) {
	for (int j = 0; j < VALUES.length; j++) {
	byte x = VALUES[i];
	byte y = VALUES[j];
	// note: spec requires only that the sign is the same
	assertEquals(
	x + ", " + y,
	Math.signum(UnsignedBytes.compare(x, y)),
	Math.signum(Ints.compare(i, j)));
	}
	}
	}

	public void testMax_noArgs() {
	try {
	UnsignedBytes.max();
	fail();
	} catch (IllegalArgumentException expected) {
	}
	}

	public void testMax() {
	assertEquals(LEAST, UnsignedBytes.max(LEAST));
	assertEquals(GREATEST, UnsignedBytes.max(GREATEST));
	assertEquals(
	(byte) 255, UnsignedBytes.max((byte) 0, (byte) -128, (byte) -1, (byte) 127, (byte) 1));
	}

	public void testMin_noArgs() {
	try {
	UnsignedBytes.min();
	fail();
	} catch (IllegalArgumentException expected) {
	}
	}

	public void testMin() {
	assertEquals(LEAST, UnsignedBytes.min(LEAST));
	assertEquals(GREATEST, UnsignedBytes.min(GREATEST));
	assertEquals(
	(byte) 0, UnsignedBytes.min((byte) 0, (byte) -128, (byte) -1, (byte) 127, (byte) 1));
	assertEquals(
	(byte) 0, UnsignedBytes.min((byte) -1, (byte) 127, (byte) 1, (byte) -128, (byte) 0));
	}

	private static void assertParseFails(String value) {
	try {
	UnsignedBytes.parseUnsignedByte(value);
	fail();
	} catch (NumberFormatException expected) {
	}
	}

	private static void assertParseFails(String value, int radix) {
	try {
	UnsignedBytes.parseUnsignedByte(value, radix);
	fail();
	} catch (NumberFormatException expected) {
	}
	}

	public void testParseUnsignedByte() {
	// We can easily afford to test this exhaustively.
	for (int i = 0; i <= 0xff; i++) {
	assertEquals((byte) i, UnsignedBytes.parseUnsignedByte(Integer.toString(i)));
	}
	assertParseFails("1000");
	assertParseFails("-1");
	assertParseFails("-128");
	assertParseFails("256");
	}

	public void testMaxValue() {
	assertTrue(
	UnsignedBytes.compare(UnsignedBytes.MAX_VALUE, (byte) (UnsignedBytes.MAX_VALUE + 1)) > 0);
	}

	public void testParseUnsignedByteWithRadix() throws NumberFormatException {
	// We can easily afford to test this exhaustively.
	for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
	for (int i = 0; i <= 0xff; i++) {
	assertEquals((byte) i, UnsignedBytes.parseUnsignedByte(Integer.toString(i, radix), radix));
	}
	assertParseFails(Integer.toString(1000, radix), radix);
	assertParseFails(Integer.toString(-1, radix), radix);
	assertParseFails(Integer.toString(-128, radix), radix);
	assertParseFails(Integer.toString(256, radix), radix);
	}
	}

	public void testParseUnsignedByteThrowsExceptionForInvalidRadix() {
	// Valid radix values are Character.MIN_RADIX to Character.MAX_RADIX,
	// inclusive.
	try {
	UnsignedBytes.parseUnsignedByte("0", Character.MIN_RADIX - 1);
	fail();
	} catch (NumberFormatException expected) {
	}

	try {
	UnsignedBytes.parseUnsignedByte("0", Character.MAX_RADIX + 1);
	fail();
	} catch (NumberFormatException expected) {
	}

	// The radix is used as an array index, so try a negative value.
	try {
	UnsignedBytes.parseUnsignedByte("0", -1);
	fail();
	} catch (NumberFormatException expected) {
	}
	}

	public void testToString() {
	// We can easily afford to test this exhaustively.
	for (int i = 0; i <= 0xff; i++) {
	assertEquals(Integer.toString(i), UnsignedBytes.toString((byte) i));
	}
	}

	public void testToStringWithRadix() {
	// We can easily afford to test this exhaustively.
	for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
	for (int i = 0; i <= 0xff; i++) {
	assertEquals(Integer.toString(i, radix), UnsignedBytes.toString((byte) i, radix));
	}
	}
	}

	public void testJoin() {
	assertEquals("", UnsignedBytes.join(",", new byte[] {}));
	assertEquals("1", UnsignedBytes.join(",", new byte[] {(byte) 1}));
	assertEquals("1,2", UnsignedBytes.join(",", (byte) 1, (byte) 2));
	assertEquals("123", UnsignedBytes.join("", (byte) 1, (byte) 2, (byte) 3));
	assertEquals("128,255", UnsignedBytes.join(",", (byte) 128, (byte) -1));
	}

	private static String unsafeComparatorClassName() {
	return UnsignedBytes.LexicographicalComparatorHolder.class.getName() + "$UnsafeComparator";
	}

	private static boolean unsafeComparatorAvailable() {
	// See Java Puzzler #44
	// Use reflection instead of catching NoClassDefFoundError
	try {
	Class.forName(unsafeComparatorClassName());
	return true;
	} catch (Error \| ClassNotFoundException tolerable) {
	/*
	* We're probably running on Android.
	*
	* A note on exception types:
	*
	* Android API level 10 throws ExceptionInInitializerError the first time and
	* ClassNotFoundException thereafter.
	*
	* Android API level 26 and JVM8 both let our Error propagate directly the first time and
	* throw NoClassDefFoundError thereafter. This is the proper behavior according to the spec.
	* See https://docs.oracle.com/javase/specs/jls/se8/html/jls-12.html#jls-12.4.2 (steps #11 and
	* #5).
	*
	* Note that that "first time" might happen in a test other than
	* testLexicographicalComparatorChoice!
	*/
	return false;
	}
	}

	public void testLexicographicalComparatorChoice() throws Exception {
	Comparator<byte[]> defaultComparator = UnsignedBytes.lexicographicalComparator();
	assertNotNull(defaultComparator);
	assertSame(defaultComparator, UnsignedBytes.lexicographicalComparator());
	if (unsafeComparatorAvailable()) {
	assertSame(defaultComparator.getClass(), Class.forName(unsafeComparatorClassName()));
	} else {
	assertSame(defaultComparator, UnsignedBytes.lexicographicalComparatorJavaImpl());
	}
	}

	public void testLexicographicalComparator() {
	List<byte[]> ordered =
	Arrays.asList(
	new byte[] {},
	new byte[] {LEAST},
	new byte[] {LEAST, LEAST},
	new byte[] {LEAST, (byte) 1},
	new byte[] {(byte) 1},
	new byte[] {(byte) 1, LEAST},
	new byte[] {GREATEST, GREATEST - (byte) 1},
	new byte[] {GREATEST, GREATEST},
	new byte[] {GREATEST, GREATEST, GREATEST});

	// The Unsafe implementation if it's available. Otherwise, the Java implementation.
	Comparator<byte[]> comparator = UnsignedBytes.lexicographicalComparator();
	Helpers.testComparator(comparator, ordered);
	assertSame(comparator, SerializableTester.reserialize(comparator));

	// The Java implementation.
	Comparator<byte[]> javaImpl = UnsignedBytes.lexicographicalComparatorJavaImpl();
	Helpers.testComparator(javaImpl, ordered);
	assertSame(javaImpl, SerializableTester.reserialize(javaImpl));
	}

	@SuppressWarnings("unchecked")
	public void testLexicographicalComparatorLongInputs() {
	Random rnd = new Random();
	for (Comparator<byte[]> comparator :
	Arrays.asList(
	UnsignedBytes.lexicographicalComparator(),
	UnsignedBytes.lexicographicalComparatorJavaImpl())) {
	for (int trials = 10; trials-- > 0; ) {
	byte[] left = new byte[1 + rnd.nextInt(32)];
	rnd.nextBytes(left);
	byte[] right = left.clone();
	assertTrue(comparator.compare(left, right) == 0);
	int i = rnd.nextInt(left.length);
	left[i] ^= (byte) (1 + rnd.nextInt(255));
	assertTrue(comparator.compare(left, right) != 0);
	assertEquals(
	comparator.compare(left, right) > 0, UnsignedBytes.compare(left[i], right[i]) > 0);
	}
	}
	}

	public void testSort() {
	testSort(new byte[] {}, new byte[] {});
	testSort(new byte[] {2}, new byte[] {2});
	testSort(new byte[] {2, 1, 0}, new byte[] {0, 1, 2});
	testSort(new byte[] {2, GREATEST, 1, LEAST}, new byte[] {LEAST, 1, 2, GREATEST});
	}

	static void testSort(byte[] input, byte[] expected) {
	input = Arrays.copyOf(input, input.length);
	UnsignedBytes.sort(input);
	assertTrue(Arrays.equals(expected, input));
	}

	static void testSort(byte[] input, int from, int to, byte[] expected) {
	input = Arrays.copyOf(input, input.length);
	UnsignedBytes.sort(input, from, to);
	assertTrue(Arrays.equals(expected, input));
	}

	public void testSortIndexed() {
	testSort(new byte[] {}, 0, 0, new byte[] {});
	testSort(new byte[] {2}, 0, 1, new byte[] {2});
	testSort(new byte[] {2, 1, 0}, 0, 2, new byte[] {1, 2, 0});
	testSort(new byte[] {2, GREATEST, 1, LEAST}, 1, 4, new byte[] {2, LEAST, 1, GREATEST});
	}

	public void testSortDescending() {
	testSortDescending(new byte[] {}, new byte[] {});
	testSortDescending(new byte[] {1}, new byte[] {1});
	testSortDescending(new byte[] {1, 2}, new byte[] {2, 1});
	testSortDescending(new byte[] {1, 3, 1}, new byte[] {3, 1, 1});
	testSortDescending(
	new byte[] {GREATEST - 1, 1, GREATEST - 2, 2},
	new byte[] {GREATEST - 1, GREATEST - 2, 2, 1});
	}

	private static void testSortDescending(byte[] input, byte[] expectedOutput) {
	input = Arrays.copyOf(input, input.length);
	UnsignedBytes.sortDescending(input);
	assertTrue(Arrays.equals(expectedOutput, input));
	}

	private static void testSortDescending(
	byte[] input, int fromIndex, int toIndex, byte[] expectedOutput) {
	input = Arrays.copyOf(input, input.length);
	UnsignedBytes.sortDescending(input, fromIndex, toIndex);
	assertTrue(Arrays.equals(expectedOutput, input));
	}

	public void testSortDescendingIndexed() {
	testSortDescending(new byte[] {}, 0, 0, new byte[] {});
	testSortDescending(new byte[] {1}, 0, 1, new byte[] {1});
	testSortDescending(new byte[] {1, 2}, 0, 2, new byte[] {2, 1});
	testSortDescending(new byte[] {1, 3, 1}, 0, 2, new byte[] {3, 1, 1});
	testSortDescending(new byte[] {1, 3, 1}, 0, 1, new byte[] {1, 3, 1});
	testSortDescending(
	new byte[] {GREATEST - 1, 1, GREATEST - 2, 2},
	1,
	3,
	new byte[] {GREATEST - 1, GREATEST - 2, 1, 2});
	}

	public void testNulls() {
	new NullPointerTester().testAllPublicStaticMethods(UnsignedBytes.class);
	}
	}