TestBitOutputStream.java

/*
  TestBitOutputStream.java

  (c) 2012 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package ejs.base.internal.test;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;

import java.io.ByteArrayOutputStream;

import org.junit.Test;

import ejs.base.utils.BitOutputStream;


/**
 * @author ejs
 *
 */
public class TestBitOutputStream {

	final ByteArrayOutputStream stockBis = new ByteArrayOutputStream();
	final ByteArrayOutputStream emptyBis = new ByteArrayOutputStream();
	
	@Test
	public void testEmpty() throws Exception {
		BitOutputStream bs = new BitOutputStream(emptyBis);
		bs.close();
		assertEquals(0, emptyBis.size());
	}
	@Test
	public void testIllegal() throws Exception  {
		BitOutputStream bs = new BitOutputStream(emptyBis);
		try {
			bs.writeBits(0, -1);
			fail();
		} catch (IllegalArgumentException e) {
			
		}
		try {
			bs.writeBits(0, 16);
			fail();
		} catch (UnsupportedOperationException e) {
		} catch (IllegalArgumentException e) {
			
		}
		bs.close();
	}
	

	@Test
	public void testSmall() throws Exception {
		BitOutputStream bs = new BitOutputStream(stockBis);
		bs.writeBits(0x55555555, 1);
		
		bs.close();
		
		byte[] bytes = stockBis.toByteArray();
		assertEquals(1, bytes.length);
		assertEquals((byte) 0x80, bytes[0]);
		
	}
	
	@Test
	public void testSmall2() throws Exception {
		BitOutputStream bs = new BitOutputStream(stockBis);
		bs.writeBits(0xffab, 8);
		
		bs.close();
		
		byte[] bytes = stockBis.toByteArray();
		assertEquals(1, bytes.length);
		assertEquals((byte) 0xab, bytes[0]);
		
	}

	@Test
	public void testCross1() throws Exception {
		BitOutputStream bs = new BitOutputStream(stockBis);
		bs.writeBits(0x0, 4);
		bs.writeBits(-1, 8);
		bs.writeBits(0x0, 4);
		
		bs.close();
		
		byte[] bytes = stockBis.toByteArray();
		assertEquals(2, bytes.length);
		assertEquals((byte) 0x0f, bytes[0]);
		assertEquals((byte) 0xf0, bytes[1]);
		
	}
	
	
	@Test
	public void testBig() throws Exception {
		BitOutputStream bs = new BitOutputStream(stockBis);
		bs.writeBits(3, 4);
		bs.writeBits(0, 1);
		bs.writeBits(0, 6);
		bs.writeBits(14, 5);
		bs.writeBits(25, 5);
		bs.writeBits(9, 4);
		bs.writeBits(7, 4);
		
		bs.writeBits(5, 4);
		bs.writeBits(0, 1);
		bs.writeBits(0, 6);
		bs.writeBits(14, 5);
		bs.writeBits(20, 5);
		bs.writeBits(9, 4);
		bs.writeBits(8, 4);
		
		bs.close();
		
		byte[] bytes = stockBis.toByteArray();
		assertEquals(8, bytes.length);
		assertEquals(0x30, bytes[0]);
		assertEquals(0x0e, bytes[1]);
		assertEquals((byte) 0xcc, bytes[2]);
		assertEquals((byte) 0xba, bytes[3]);
		assertEquals((byte) 0x80, bytes[4]);
		assertEquals((byte) 0x75, bytes[5]);
		assertEquals((byte) 0x26, bytes[6]);
		assertEquals((byte) 0x0, bytes[7]);
		
	}
	
}