/*
    * Copyright (C) 2008, Google Inc.
    * and other copyright owners as documented in the project's IP log.
    *
    * This program and the accompanying materials are made available
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    * accompanies this distribution, is reproduced below, and is
    * available at http://www.eclipse.org/org/documents/edl-v10.php
    *
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  package org.eclipse.jgit.treewalk;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertSame;
  import static org.junit.Assert.assertTrue;
  
  import org.eclipse.jgit.junit.RepositoryTestCase;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.ObjectReader;
  import org.junit.Test;
  
  public class EmptyTreeIteratorTest extends RepositoryTestCase {
  	@Test
  	public void testAtEOF() throws Exception {
  		final EmptyTreeIterator etp = new EmptyTreeIterator();
  		assertTrue(etp.first());
  		assertTrue(etp.eof());
  	}
  
  	@Test
  	public void testCreateSubtreeIterator() throws Exception {
  		final EmptyTreeIterator etp = new EmptyTreeIterator();
  		final ObjectReader reader = db.newObjectReader();
  		final AbstractTreeIterator sub = etp.createSubtreeIterator(reader);
  		assertNotNull(sub);
  		assertTrue(sub.first());
  		assertTrue(sub.eof());
  		assertTrue(sub instanceof EmptyTreeIterator);
  	}
  
  	@Test
  	public void testEntryObjectId() throws Exception {
  		final EmptyTreeIterator etp = new EmptyTreeIterator();
  		assertSame(ObjectId.zeroId(), etp.getEntryObjectId());
  		assertNotNull(etp.idBuffer());
  		assertEquals(0, etp.idOffset());
  		assertEquals(ObjectId.zeroId(), ObjectId.fromRaw(etp.idBuffer()));
  	}
  
  	@Test
  	public void testNextDoesNothing() throws Exception {
  		final EmptyTreeIterator etp = new EmptyTreeIterator();
  		etp.next(1);
  		assertTrue(etp.first());
  		assertTrue(etp.eof());
  		assertEquals(ObjectId.zeroId(), ObjectId.fromRaw(etp.idBuffer()));
  
  		etp.next(1);
  		assertTrue(etp.first());
  		assertTrue(etp.eof());
  		assertEquals(ObjectId.zeroId(), ObjectId.fromRaw(etp.idBuffer()));
  	}
  
  	@Test
 	public void testBackDoesNothing() throws Exception {
 		final EmptyTreeIterator etp = new EmptyTreeIterator();
 		etp.back(1);
 		assertTrue(etp.first());
 		assertTrue(etp.eof());
 		assertEquals(ObjectId.zeroId(), ObjectId.fromRaw(etp.idBuffer()));
 
 		etp.back(1);
 		assertTrue(etp.first());
 		assertTrue(etp.eof());
 		assertEquals(ObjectId.zeroId(), ObjectId.fromRaw(etp.idBuffer()));
 	}
 
 	@Test
 	public void testStopWalkCallsParent() throws Exception {
 		final boolean called[] = new boolean[1];
 		assertFalse(called[0]);
 
 		final EmptyTreeIterator parent = new EmptyTreeIterator() {
 			@Override
 			public void stopWalk() {
 				called[0] = true;
 			}
 		};
 		final ObjectReader reader = db.newObjectReader();
 		parent.createSubtreeIterator(reader).stopWalk();
 		assertTrue(called[0]);
 	}
 }