org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/AbbreviatedLongObjectIdTest.java - sop/jgit - Git at Google

 /*
  * Copyright (C) 2015, Matthias Sohn <matthias.sohn@sap.com>
  * and other copyright owners as documented in the project's IP log.
  *
  * This program and the accompanying materials are made available
  * under the terms of the Eclipse Distribution License v1.0 which
  * accompanies this distribution, is reproduced below, and is
  * available at http://www.eclipse.org/org/documents/edl-v10.php
  *
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or
  * without modification, are permitted provided that the following
  * conditions are met:
  *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  *
  * - Redistributions in binary form must reproduce the above
  *   copyright notice, this list of conditions and the following
  *   disclaimer in the documentation and/or other materials provided
  *   with the distribution.
  *
  * - Neither the name of the Eclipse Foundation, Inc. nor the
  *   names of its contributors may be used to endorse or promote
  *   products derived from this software without specific prior
  *   written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 package org.eclipse.jgit.lfs.lib;

 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNotSame;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;

 import org.eclipse.jgit.lfs.test.LongObjectIdTestUtils;
 import org.junit.Test;

 /*
  * Ported to SHA-256 from org.eclipse.jgit.lib.AbbreviatedObjectIdTest
  */
 public class AbbreviatedLongObjectIdTest {
 	@Test
 	public void testEmpty_FromByteArray() {
 		final AbbreviatedLongObjectId i;
 		i = AbbreviatedLongObjectId.fromString(new byte[] {}, 0, 0);
 		assertNotNull(i);
 		assertEquals(0, i.length());
 		assertFalse(i.isComplete());
 		assertEquals("", i.name());
 	}

 	@Test
 	public void testEmpty_FromString() {
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId
 				.fromString("");
 		assertNotNull(i);
 		assertEquals(0, i.length());
 		assertFalse(i.isComplete());
 		assertEquals("", i.name());
 	}

 	@Test
 	public void testFull_FromByteArray() {
 		final String s = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final byte[] b = org.eclipse.jgit.lib.Constants.encodeASCII(s);
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(b,
 				0, b.length);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertTrue(i.isComplete());
 		assertEquals(s, i.name());

 		final LongObjectId f = i.toLongObjectId();
 		assertNotNull(f);
 		assertEquals(LongObjectId.fromString(s), f);
 		assertEquals(f.hashCode(), i.hashCode());
 	}

 	@Test
 	public void testFull_FromString() {
 		final String s = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertTrue(i.isComplete());
 		assertEquals(s, i.name());

 		final LongObjectId f = i.toLongObjectId();
 		assertNotNull(f);
 		assertEquals(LongObjectId.fromString(s), f);
 		assertEquals(f.hashCode(), i.hashCode());
 	}

 	@Test
 	public void test1_FromString() {
 		final String s = "2";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test2_FromString() {
 		final String s = "27";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test3_FromString() {
 		final String s = "27e";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test4_FromString() {
 		final String s = "27e1";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test5_FromString() {
 		final String s = "27e15";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test6_FromString() {
 		final String s = "27e15b";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test7_FromString() {
 		final String s = "27e15b7";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test8_FromString() {
 		final String s = "27e15b72";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test9_FromString() {
 		final String s = "27e15b729";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test15_FromString() {
 		final String s = "27e15b72937fc8f";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test16_FromString() {
 		final String s = "27e15b72937fc8f5";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test17_FromString() {
 		final String s = "27e15b72937fc8f55";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void test33_FromString() {
 		final String s = "27e15b72937fc8f558da24ac3d50ec203";
 		final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
 		assertNotNull(i);
 		assertEquals(s.length(), i.length());
 		assertFalse(i.isComplete());
 		assertEquals(s, i.name());
 		assertNull(i.toLongObjectId());
 	}

 	@Test
 	public void testEquals_Short() {
 		final String s = "27e15b72";
 		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId.fromString(s);
 		final AbbreviatedLongObjectId b = AbbreviatedLongObjectId.fromString(s);
 		assertNotSame(a, b);
 		assertTrue(a.hashCode() == b.hashCode());
 		assertEquals(b, a);
 		assertEquals(a, b);
 	}

 	@Test
 	public void testEquals_Full() {
 		final String s = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId.fromString(s);
 		final AbbreviatedLongObjectId b = AbbreviatedLongObjectId.fromString(s);
 		assertNotSame(a, b);
 		assertTrue(a.hashCode() == b.hashCode());
 		assertEquals(b, a);
 		assertEquals(a, b);
 	}

 	@Test
 	public void testNotEquals_SameLength() {
 		final String sa = "27e15b72";
 		final String sb = "27e15b7f";
 		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
 				.fromString(sa);
 		final AbbreviatedLongObjectId b = AbbreviatedLongObjectId
 				.fromString(sb);
 		assertFalse(a.equals(b));
 		assertFalse(b.equals(a));
 	}

 	@Test
 	public void testNotEquals_DiffLength() {
 		final String sa = "27e15b72abcd";
 		final String sb = "27e15b72";
 		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
 				.fromString(sa);
 		final AbbreviatedLongObjectId b = AbbreviatedLongObjectId
 				.fromString(sb);
 		assertFalse(a.equals(b));
 		assertFalse(b.equals(a));
 	}

 	@Test
 	public void testPrefixCompare_Full() {
 		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
 				.fromString(s1);
 		final LongObjectId i1 = LongObjectId.fromString(s1);
 		assertEquals(0, a.prefixCompare(i1));
 		assertTrue(i1.startsWith(a));

 		final String s2 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b11";
 		final LongObjectId i2 = LongObjectId.fromString(s2);
 		assertTrue(a.prefixCompare(i2) < 0);
 		assertFalse(i2.startsWith(a));

 		final String s3 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b0f";
 		final LongObjectId i3 = LongObjectId.fromString(s3);
 		assertTrue(a.prefixCompare(i3) > 0);
 		assertFalse(i3.startsWith(a));
 	}

 	@Test
 	public void testPrefixCompare_1() {
 		final String sa = "2";
 		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
 				.fromString(sa);

 		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i1 = LongObjectId.fromString(s1);
 		assertEquals(0, a.prefixCompare(i1));
 		assertTrue(i1.startsWith(a));

 		final String s2 = "37e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i2 = LongObjectId.fromString(s2);
 		assertTrue(a.prefixCompare(i2) < 0);
 		assertFalse(i2.startsWith(a));

 		final String s3 = "17e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i3 = LongObjectId.fromString(s3);
 		assertTrue(a.prefixCompare(i3) > 0);
 		assertFalse(i3.startsWith(a));
 	}

 	@Test
 	public void testPrefixCompare_15() {
 		final String sa = "27e15b72937fc8f";
 		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
 				.fromString(sa);

 		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i1 = LongObjectId.fromString(s1);
 		assertEquals(0, a.prefixCompare(i1));
 		assertTrue(i1.startsWith(a));

 		final String s2 = "27e15b72937fc90558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i2 = LongObjectId.fromString(s2);
 		assertTrue(a.prefixCompare(i2) < 0);
 		assertFalse(i2.startsWith(a));

 		final String s3 = "27e15b72937fc8e558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i3 = LongObjectId.fromString(s3);
 		assertTrue(a.prefixCompare(i3) > 0);
 		assertFalse(i3.startsWith(a));
 	}

 	@Test
 	public void testPrefixCompare_16() {
 		final String sa = "27e15b72937fc8f5";
 		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
 				.fromString(sa);

 		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i1 = LongObjectId.fromString(s1);
 		assertEquals(0, a.prefixCompare(i1));
 		assertTrue(i1.startsWith(a));

 		final String s2 = "27e15b72937fc8f658da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i2 = LongObjectId.fromString(s2);
 		assertTrue(a.prefixCompare(i2) < 0);
 		assertFalse(i2.startsWith(a));

 		final String s3 = "27e15b72937fc8f458da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i3 = LongObjectId.fromString(s3);
 		assertTrue(a.prefixCompare(i3) > 0);
 		assertFalse(i3.startsWith(a));
 	}

 	@Test
 	public void testPrefixCompare_17() {
 		final String sa = "27e15b72937fc8f55";
 		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
 				.fromString(sa);

 		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i1 = LongObjectId.fromString(s1);
 		assertEquals(0, a.prefixCompare(i1));
 		assertTrue(i1.startsWith(a));

 		final String s2 = "27e15b72937fc8f568da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i2 = LongObjectId.fromString(s2);
 		assertTrue(a.prefixCompare(i2) < 0);
 		assertFalse(i2.startsWith(a));

 		final String s3 = "27e15b72937fc8f548da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i3 = LongObjectId.fromString(s3);
 		assertTrue(a.prefixCompare(i3) > 0);
 		assertFalse(i3.startsWith(a));
 	}

 	@Test
 	public void testPrefixCompare_33() {
 		final String sa = "27e15b72937fc8f558da24ac3d50ec203";
 		final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
 				.fromString(sa);

 		final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i1 = LongObjectId.fromString(s1);
 		assertEquals(0, a.prefixCompare(i1));
 		assertTrue(i1.startsWith(a));

 		final String s2 = "27e15b72937fc8f558da24ac3d50ec20402a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i2 = LongObjectId.fromString(s2);
 		assertTrue(a.prefixCompare(i2) < 0);
 		assertFalse(i2.startsWith(a));

 		final String s3 = "27e15b72937fc8f558da24ac3d50ec20202a4cf21e33b87ae8e4ce90e89c4b10";
 		final LongObjectId i3 = LongObjectId.fromString(s3);
 		assertTrue(a.prefixCompare(i3) > 0);
 		assertFalse(i3.startsWith(a));
 	}

 	@Test
 	public void testIsId() {
 		// These are all too short.
 		assertFalse(AbbreviatedLongObjectId.isId(""));
 		assertFalse(AbbreviatedLongObjectId.isId("a"));

 		// These are too long.
 		assertFalse(AbbreviatedLongObjectId.isId(LongObjectId
 				.fromString(
 						"27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10")
 				.name() + "0"));
 		assertFalse(AbbreviatedLongObjectId.isId(LongObjectId
 				.fromString(
 						"27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10")
 				.name() + "c0ffee"));

 		// These contain non-hex characters.
 		assertFalse(AbbreviatedLongObjectId.isId("01notahexstring"));

 		// These should all work.
 		assertTrue(AbbreviatedLongObjectId.isId("ab"));
 		assertTrue(AbbreviatedLongObjectId.isId("abc"));
 		assertTrue(AbbreviatedLongObjectId.isId("abcd"));
 		assertTrue(AbbreviatedLongObjectId.isId("abcd0"));
 		assertTrue(AbbreviatedLongObjectId.isId("abcd09"));
 		assertTrue(AbbreviatedLongObjectId.isId(LongObjectId
 				.fromString(
 						"27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10")
 				.name()));
 	}

 	@Test
 	public void testAbbreviate() {
 		AnyLongObjectId id = LongObjectIdTestUtils.hash("test");
 		assertEquals(
 				"abbreviated id should match the id it was abbreviated from", 0,
 				id.abbreviate(10).prefixCompare(id));
 	}

 	@Test
 	public void testFromStringByteWrongLength() {
 		byte[] buf = new byte[65];
 		try {
 			AbbreviatedLongObjectId.fromString(buf, 0, 65);
 			fail("expected IllegalArgumentException for too long AbbreviatedLongObjectId");
 		} catch (IllegalArgumentException e) {
 			// expected
 		}
 	}

 	@Test
 	public void testFromStringWrongLength() {
 		AnyLongObjectId id = LongObjectIdTestUtils.hash("test");
 		try {
 			AbbreviatedLongObjectId.fromString(id.name() + "c0ffee");
 			fail("expected IllegalArgumentException for too long AbbreviatedLongObjectId");
 		} catch (IllegalArgumentException e) {
 			// expected
 		}
 	}

 	@Test
 	public void testFromLongObjectId() {
 		AnyLongObjectId id = LongObjectIdTestUtils.hash("test");
 		assertEquals(0,
 				AbbreviatedLongObjectId.fromLongObjectId(id).prefixCompare(id));
 	}

 	@Test
 	public void testPrefixCompareByte() {
 		AnyLongObjectId id = LongObjectId.fromString(
 				"0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef");
 		byte[] buf = new byte[32];
 		id.copyRawTo(buf, 0);

 		AbbreviatedLongObjectId a = id.abbreviate(62);
 		assertEquals(0, a.prefixCompare(buf, 0));

 		a = LongObjectId
 				.fromString(
 						"0023456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")
 				.abbreviate(16);
 		assertEquals(-1, a.prefixCompare(buf, 0));
 		a = LongObjectId
 				.fromString(
 						"0123456789abcdef0023456789abcdef0123456789abcdef0123456789abcdef")
 				.abbreviate(32);
 		assertEquals(-1, a.prefixCompare(buf, 0));
 		a = LongObjectId
 				.fromString(
 						"0123456789abcdef0123456789abcdef0023456789abcdef0123456789abcdef")
 				.abbreviate(48);
 		assertEquals(-1, a.prefixCompare(buf, 0));
 		a = LongObjectId
 				.fromString(
 						"0123456789abcdef0123456789abcdef0123456789abcdef0023456789abcdef")
 				.abbreviate(64);
 		assertEquals(-1, a.prefixCompare(buf, 0));

 		a = LongObjectId
 				.fromString(
 						"1123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")
 				.abbreviate(16);
 		assertEquals(1, a.prefixCompare(buf, 0));
 		a = LongObjectId
 				.fromString(
 						"0123456789abcdef1123456789abcdef0123456789abcdef0123456789abcdef")
 				.abbreviate(32);
 		assertEquals(1, a.prefixCompare(buf, 0));
 		a = LongObjectId
 				.fromString(
 						"0123456789abcdef0123456789abcdef1123456789abcdef0123456789abcdef")
 				.abbreviate(48);
 		assertEquals(1, a.prefixCompare(buf, 0));
 		a = LongObjectId
 				.fromString(
 						"0123456789abcdef0123456789abcdef0123456789abcdef1123456789abcdef")
 				.abbreviate(64);
 		assertEquals(1, a.prefixCompare(buf, 0));
 	}

 	@Test
 	public void testPrefixCompareLong() {
 		AnyLongObjectId id = new LongObjectId(1L, 2L, 3L, 4L);
 		long[] buf = new long[4];
 		id.copyRawTo(buf, 0);

 		AbbreviatedLongObjectId a = id.abbreviate(62);
 		assertEquals(0, a.prefixCompare(buf, 0));

 		a = new LongObjectId(0L, 2L, 3L, 4L).abbreviate(16);
 		assertEquals(-1, a.prefixCompare(buf, 0));
 		a = new LongObjectId(1L, 1L, 3L, 4L).abbreviate(32);
 		assertEquals(-1, a.prefixCompare(buf, 0));
 		a = new LongObjectId(1L, 2L, 2L, 4L).abbreviate(48);
 		assertEquals(-1, a.prefixCompare(buf, 0));
 		a = new LongObjectId(1L, 2L, 3L, 3L).abbreviate(64);
 		assertEquals(-1, a.prefixCompare(buf, 0));

 		a = new LongObjectId(2L, 2L, 3L, 4L).abbreviate(16);
 		assertEquals(1, a.prefixCompare(buf, 0));
 		a = new LongObjectId(1L, 3L, 3L, 4L).abbreviate(32);
 		assertEquals(1, a.prefixCompare(buf, 0));
 		a = new LongObjectId(1L, 2L, 4L, 4L).abbreviate(48);
 		assertEquals(1, a.prefixCompare(buf, 0));
 		a = new LongObjectId(1L, 2L, 3L, 5L).abbreviate(64);
 		assertEquals(1, a.prefixCompare(buf, 0));
 	}

 	@Test
 	public void testGetFirstByte() {
 		AnyLongObjectId id = LongObjectId.fromString(
 				"f423456789abcdef0123456789abcdef0123456789abcdef1123456789abcdef");
 		AbbreviatedLongObjectId a = id.abbreviate(10);
 		assertEquals(0xf4, a.getFirstByte());
 		assertEquals(id.getFirstByte(), a.getFirstByte());
 	}

 	@Test
 	public void testNotEquals() {
 		AbbreviatedLongObjectId a = new LongObjectId(1L, 2L, 3L, 4L)
 				.abbreviate(10);
 		assertFalse(a.equals("different"));
 	}
 }
	/*
	* Copyright (C) 2015, Matthias Sohn <matthias.sohn@sap.com>
	* and other copyright owners as documented in the project's IP log.
	*
	* This program and the accompanying materials are made available
	* under the terms of the Eclipse Distribution License v1.0 which
	* accompanies this distribution, is reproduced below, and is
	* available at http://www.eclipse.org/org/documents/edl-v10.php
	*
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or
	* without modification, are permitted provided that the following
	* conditions are met:
	*
	* - Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	*
	* - Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials provided
	* with the distribution.
	*
	* - Neither the name of the Eclipse Foundation, Inc. nor the
	* names of its contributors may be used to endorse or promote
	* products derived from this software without specific prior
	* written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
	* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
	* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
	* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	package org.eclipse.jgit.lfs.lib;

	import static org.junit.Assert.assertEquals;
	import static org.junit.Assert.assertFalse;
	import static org.junit.Assert.assertNotNull;
	import static org.junit.Assert.assertNotSame;
	import static org.junit.Assert.assertNull;
	import static org.junit.Assert.assertTrue;
	import static org.junit.Assert.fail;

	import org.eclipse.jgit.lfs.test.LongObjectIdTestUtils;
	import org.junit.Test;

	/*
	* Ported to SHA-256 from org.eclipse.jgit.lib.AbbreviatedObjectIdTest
	*/
	public class AbbreviatedLongObjectIdTest {
	@Test
	public void testEmpty_FromByteArray() {
	final AbbreviatedLongObjectId i;
	i = AbbreviatedLongObjectId.fromString(new byte[] {}, 0, 0);
	assertNotNull(i);
	assertEquals(0, i.length());
	assertFalse(i.isComplete());
	assertEquals("", i.name());
	}

	@Test
	public void testEmpty_FromString() {
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId
	.fromString("");
	assertNotNull(i);
	assertEquals(0, i.length());
	assertFalse(i.isComplete());
	assertEquals("", i.name());
	}

	@Test
	public void testFull_FromByteArray() {
	final String s = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final byte[] b = org.eclipse.jgit.lib.Constants.encodeASCII(s);
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(b,
	0, b.length);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertTrue(i.isComplete());
	assertEquals(s, i.name());

	final LongObjectId f = i.toLongObjectId();
	assertNotNull(f);
	assertEquals(LongObjectId.fromString(s), f);
	assertEquals(f.hashCode(), i.hashCode());
	}

	@Test
	public void testFull_FromString() {
	final String s = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertTrue(i.isComplete());
	assertEquals(s, i.name());

	final LongObjectId f = i.toLongObjectId();
	assertNotNull(f);
	assertEquals(LongObjectId.fromString(s), f);
	assertEquals(f.hashCode(), i.hashCode());
	}

	@Test
	public void test1_FromString() {
	final String s = "2";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test2_FromString() {
	final String s = "27";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test3_FromString() {
	final String s = "27e";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test4_FromString() {
	final String s = "27e1";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test5_FromString() {
	final String s = "27e15";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test6_FromString() {
	final String s = "27e15b";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test7_FromString() {
	final String s = "27e15b7";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test8_FromString() {
	final String s = "27e15b72";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test9_FromString() {
	final String s = "27e15b729";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test15_FromString() {
	final String s = "27e15b72937fc8f";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test16_FromString() {
	final String s = "27e15b72937fc8f5";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test17_FromString() {
	final String s = "27e15b72937fc8f55";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void test33_FromString() {
	final String s = "27e15b72937fc8f558da24ac3d50ec203";
	final AbbreviatedLongObjectId i = AbbreviatedLongObjectId.fromString(s);
	assertNotNull(i);
	assertEquals(s.length(), i.length());
	assertFalse(i.isComplete());
	assertEquals(s, i.name());
	assertNull(i.toLongObjectId());
	}

	@Test
	public void testEquals_Short() {
	final String s = "27e15b72";
	final AbbreviatedLongObjectId a = AbbreviatedLongObjectId.fromString(s);
	final AbbreviatedLongObjectId b = AbbreviatedLongObjectId.fromString(s);
	assertNotSame(a, b);
	assertTrue(a.hashCode() == b.hashCode());
	assertEquals(b, a);
	assertEquals(a, b);
	}

	@Test
	public void testEquals_Full() {
	final String s = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final AbbreviatedLongObjectId a = AbbreviatedLongObjectId.fromString(s);
	final AbbreviatedLongObjectId b = AbbreviatedLongObjectId.fromString(s);
	assertNotSame(a, b);
	assertTrue(a.hashCode() == b.hashCode());
	assertEquals(b, a);
	assertEquals(a, b);
	}

	@Test
	public void testNotEquals_SameLength() {
	final String sa = "27e15b72";
	final String sb = "27e15b7f";
	final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
	.fromString(sa);
	final AbbreviatedLongObjectId b = AbbreviatedLongObjectId
	.fromString(sb);
	assertFalse(a.equals(b));
	assertFalse(b.equals(a));
	}

	@Test
	public void testNotEquals_DiffLength() {
	final String sa = "27e15b72abcd";
	final String sb = "27e15b72";
	final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
	.fromString(sa);
	final AbbreviatedLongObjectId b = AbbreviatedLongObjectId
	.fromString(sb);
	assertFalse(a.equals(b));
	assertFalse(b.equals(a));
	}

	@Test
	public void testPrefixCompare_Full() {
	final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
	.fromString(s1);
	final LongObjectId i1 = LongObjectId.fromString(s1);
	assertEquals(0, a.prefixCompare(i1));
	assertTrue(i1.startsWith(a));

	final String s2 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b11";
	final LongObjectId i2 = LongObjectId.fromString(s2);
	assertTrue(a.prefixCompare(i2) < 0);
	assertFalse(i2.startsWith(a));

	final String s3 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b0f";
	final LongObjectId i3 = LongObjectId.fromString(s3);
	assertTrue(a.prefixCompare(i3) > 0);
	assertFalse(i3.startsWith(a));
	}

	@Test
	public void testPrefixCompare_1() {
	final String sa = "2";
	final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
	.fromString(sa);

	final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i1 = LongObjectId.fromString(s1);
	assertEquals(0, a.prefixCompare(i1));
	assertTrue(i1.startsWith(a));

	final String s2 = "37e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i2 = LongObjectId.fromString(s2);
	assertTrue(a.prefixCompare(i2) < 0);
	assertFalse(i2.startsWith(a));

	final String s3 = "17e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i3 = LongObjectId.fromString(s3);
	assertTrue(a.prefixCompare(i3) > 0);
	assertFalse(i3.startsWith(a));
	}

	@Test
	public void testPrefixCompare_15() {
	final String sa = "27e15b72937fc8f";
	final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
	.fromString(sa);

	final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i1 = LongObjectId.fromString(s1);
	assertEquals(0, a.prefixCompare(i1));
	assertTrue(i1.startsWith(a));

	final String s2 = "27e15b72937fc90558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i2 = LongObjectId.fromString(s2);
	assertTrue(a.prefixCompare(i2) < 0);
	assertFalse(i2.startsWith(a));

	final String s3 = "27e15b72937fc8e558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i3 = LongObjectId.fromString(s3);
	assertTrue(a.prefixCompare(i3) > 0);
	assertFalse(i3.startsWith(a));
	}

	@Test
	public void testPrefixCompare_16() {
	final String sa = "27e15b72937fc8f5";
	final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
	.fromString(sa);

	final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i1 = LongObjectId.fromString(s1);
	assertEquals(0, a.prefixCompare(i1));
	assertTrue(i1.startsWith(a));

	final String s2 = "27e15b72937fc8f658da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i2 = LongObjectId.fromString(s2);
	assertTrue(a.prefixCompare(i2) < 0);
	assertFalse(i2.startsWith(a));

	final String s3 = "27e15b72937fc8f458da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i3 = LongObjectId.fromString(s3);
	assertTrue(a.prefixCompare(i3) > 0);
	assertFalse(i3.startsWith(a));
	}

	@Test
	public void testPrefixCompare_17() {
	final String sa = "27e15b72937fc8f55";
	final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
	.fromString(sa);

	final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i1 = LongObjectId.fromString(s1);
	assertEquals(0, a.prefixCompare(i1));
	assertTrue(i1.startsWith(a));

	final String s2 = "27e15b72937fc8f568da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i2 = LongObjectId.fromString(s2);
	assertTrue(a.prefixCompare(i2) < 0);
	assertFalse(i2.startsWith(a));

	final String s3 = "27e15b72937fc8f548da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i3 = LongObjectId.fromString(s3);
	assertTrue(a.prefixCompare(i3) > 0);
	assertFalse(i3.startsWith(a));
	}

	@Test
	public void testPrefixCompare_33() {
	final String sa = "27e15b72937fc8f558da24ac3d50ec203";
	final AbbreviatedLongObjectId a = AbbreviatedLongObjectId
	.fromString(sa);

	final String s1 = "27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i1 = LongObjectId.fromString(s1);
	assertEquals(0, a.prefixCompare(i1));
	assertTrue(i1.startsWith(a));

	final String s2 = "27e15b72937fc8f558da24ac3d50ec20402a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i2 = LongObjectId.fromString(s2);
	assertTrue(a.prefixCompare(i2) < 0);
	assertFalse(i2.startsWith(a));

	final String s3 = "27e15b72937fc8f558da24ac3d50ec20202a4cf21e33b87ae8e4ce90e89c4b10";
	final LongObjectId i3 = LongObjectId.fromString(s3);
	assertTrue(a.prefixCompare(i3) > 0);
	assertFalse(i3.startsWith(a));
	}

	@Test
	public void testIsId() {
	// These are all too short.
	assertFalse(AbbreviatedLongObjectId.isId(""));
	assertFalse(AbbreviatedLongObjectId.isId("a"));

	// These are too long.
	assertFalse(AbbreviatedLongObjectId.isId(LongObjectId
	.fromString(
	"27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10")
	.name() + "0"));
	assertFalse(AbbreviatedLongObjectId.isId(LongObjectId
	.fromString(
	"27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10")
	.name() + "c0ffee"));

	// These contain non-hex characters.
	assertFalse(AbbreviatedLongObjectId.isId("01notahexstring"));

	// These should all work.
	assertTrue(AbbreviatedLongObjectId.isId("ab"));
	assertTrue(AbbreviatedLongObjectId.isId("abc"));
	assertTrue(AbbreviatedLongObjectId.isId("abcd"));
	assertTrue(AbbreviatedLongObjectId.isId("abcd0"));
	assertTrue(AbbreviatedLongObjectId.isId("abcd09"));
	assertTrue(AbbreviatedLongObjectId.isId(LongObjectId
	.fromString(
	"27e15b72937fc8f558da24ac3d50ec20302a4cf21e33b87ae8e4ce90e89c4b10")
	.name()));
	}

	@Test
	public void testAbbreviate() {
	AnyLongObjectId id = LongObjectIdTestUtils.hash("test");
	assertEquals(
	"abbreviated id should match the id it was abbreviated from", 0,
	id.abbreviate(10).prefixCompare(id));
	}

	@Test
	public void testFromStringByteWrongLength() {
	byte[] buf = new byte[65];
	try {
	AbbreviatedLongObjectId.fromString(buf, 0, 65);
	fail("expected IllegalArgumentException for too long AbbreviatedLongObjectId");
	} catch (IllegalArgumentException e) {
	// expected
	}
	}

	@Test
	public void testFromStringWrongLength() {
	AnyLongObjectId id = LongObjectIdTestUtils.hash("test");
	try {
	AbbreviatedLongObjectId.fromString(id.name() + "c0ffee");
	fail("expected IllegalArgumentException for too long AbbreviatedLongObjectId");
	} catch (IllegalArgumentException e) {
	// expected
	}
	}

	@Test
	public void testFromLongObjectId() {
	AnyLongObjectId id = LongObjectIdTestUtils.hash("test");
	assertEquals(0,
	AbbreviatedLongObjectId.fromLongObjectId(id).prefixCompare(id));
	}

	@Test
	public void testPrefixCompareByte() {
	AnyLongObjectId id = LongObjectId.fromString(
	"0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef");
	byte[] buf = new byte[32];
	id.copyRawTo(buf, 0);

	AbbreviatedLongObjectId a = id.abbreviate(62);
	assertEquals(0, a.prefixCompare(buf, 0));

	a = LongObjectId
	.fromString(
	"0023456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")
	.abbreviate(16);
	assertEquals(-1, a.prefixCompare(buf, 0));
	a = LongObjectId
	.fromString(
	"0123456789abcdef0023456789abcdef0123456789abcdef0123456789abcdef")
	.abbreviate(32);
	assertEquals(-1, a.prefixCompare(buf, 0));
	a = LongObjectId
	.fromString(
	"0123456789abcdef0123456789abcdef0023456789abcdef0123456789abcdef")
	.abbreviate(48);
	assertEquals(-1, a.prefixCompare(buf, 0));
	a = LongObjectId
	.fromString(
	"0123456789abcdef0123456789abcdef0123456789abcdef0023456789abcdef")
	.abbreviate(64);
	assertEquals(-1, a.prefixCompare(buf, 0));

	a = LongObjectId
	.fromString(
	"1123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")
	.abbreviate(16);
	assertEquals(1, a.prefixCompare(buf, 0));
	a = LongObjectId
	.fromString(
	"0123456789abcdef1123456789abcdef0123456789abcdef0123456789abcdef")
	.abbreviate(32);
	assertEquals(1, a.prefixCompare(buf, 0));
	a = LongObjectId
	.fromString(
	"0123456789abcdef0123456789abcdef1123456789abcdef0123456789abcdef")
	.abbreviate(48);
	assertEquals(1, a.prefixCompare(buf, 0));
	a = LongObjectId
	.fromString(
	"0123456789abcdef0123456789abcdef0123456789abcdef1123456789abcdef")
	.abbreviate(64);
	assertEquals(1, a.prefixCompare(buf, 0));
	}

	@Test
	public void testPrefixCompareLong() {
	AnyLongObjectId id = new LongObjectId(1L, 2L, 3L, 4L);
	long[] buf = new long[4];
	id.copyRawTo(buf, 0);

	AbbreviatedLongObjectId a = id.abbreviate(62);
	assertEquals(0, a.prefixCompare(buf, 0));

	a = new LongObjectId(0L, 2L, 3L, 4L).abbreviate(16);
	assertEquals(-1, a.prefixCompare(buf, 0));
	a = new LongObjectId(1L, 1L, 3L, 4L).abbreviate(32);
	assertEquals(-1, a.prefixCompare(buf, 0));
	a = new LongObjectId(1L, 2L, 2L, 4L).abbreviate(48);
	assertEquals(-1, a.prefixCompare(buf, 0));
	a = new LongObjectId(1L, 2L, 3L, 3L).abbreviate(64);
	assertEquals(-1, a.prefixCompare(buf, 0));

	a = new LongObjectId(2L, 2L, 3L, 4L).abbreviate(16);
	assertEquals(1, a.prefixCompare(buf, 0));
	a = new LongObjectId(1L, 3L, 3L, 4L).abbreviate(32);
	assertEquals(1, a.prefixCompare(buf, 0));
	a = new LongObjectId(1L, 2L, 4L, 4L).abbreviate(48);
	assertEquals(1, a.prefixCompare(buf, 0));
	a = new LongObjectId(1L, 2L, 3L, 5L).abbreviate(64);
	assertEquals(1, a.prefixCompare(buf, 0));
	}

	@Test
	public void testGetFirstByte() {
	AnyLongObjectId id = LongObjectId.fromString(
	"f423456789abcdef0123456789abcdef0123456789abcdef1123456789abcdef");
	AbbreviatedLongObjectId a = id.abbreviate(10);
	assertEquals(0xf4, a.getFirstByte());
	assertEquals(id.getFirstByte(), a.getFirstByte());
	}

	@Test
	public void testNotEquals() {
	AbbreviatedLongObjectId a = new LongObjectId(1L, 2L, 3L, 4L)
	.abbreviate(10);
	assertFalse(a.equals("different"));
	}
	}