MotorDigestTest.java

package net.sf.openrocket.motor;

import static org.junit.Assert.assertEquals;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import net.sf.openrocket.motor.MotorDigest.DataType;
import net.sf.openrocket.util.TextUtil;

import org.junit.Test;


public class MotorDigestTest {
	
	private static final double[] timeArray = {
		0.0, 0.123456789, 0.4115, Math.nextAfter(Math.nextAfter(1.4445, 0), 0)
	};
	
	private static final double[] massArray = {
		0.54321, 0.43211
	};
	
	private static final double[] thrustArray = {
		0.0, 0.2345678, 9999.3335, 0.0
	};
	
	private static final int[] intData = {
		// Time (ms)
		0, 4,   0, 123, 412, 1445,
		// Mass specific (0.1g)
		1, 2,   5432, 4321,
		// Thrust (mN)
		5, 4,   0, 235, 9999334, 0
	};
	

	@Test
	public void testMotorDigest() throws NoSuchAlgorithmException {
		
		MessageDigest correct = MessageDigest.getInstance("MD5");
		for (int value: intData) {
			correct.update((byte) ((value >>> 24) & 0xFF));
			correct.update((byte) ((value >>> 16) & 0xFF));
			correct.update((byte) ((value >>> 8) & 0xFF));
			correct.update((byte) (value & 0xFF));
		}
		
		MotorDigest motor = new MotorDigest();
		motor.update(DataType.TIME_ARRAY, timeArray);
		motor.update(DataType.MASS_SPECIFIC, massArray);
		motor.update(DataType.FORCE_PER_TIME, thrustArray);
		
		
		assertEquals(TextUtil.hexString(correct.digest()), motor.getDigest());
	}
	
	
	@Test
	public void testCommentDigest() throws NoSuchAlgorithmException, UnsupportedEncodingException {
		
		assertEquals(md5("Hello world!"), MotorDigest.digestComment("Hello  world! "));
		assertEquals(md5("Hello world!"), MotorDigest.digestComment("\nHello\tworld!\n\r"));
		assertEquals(md5("Hello world!"), MotorDigest.digestComment("Hello\r\r\r\nworld!"));
		assertEquals(md5("Hello\u00e4 world!"), MotorDigest.digestComment("Hello\u00e4\r\r\nworld!"));
		
	}
	
	
	private static String md5(String source) 
	throws NoSuchAlgorithmException, UnsupportedEncodingException {
		MessageDigest digest = MessageDigest.getInstance("MD5");
		return TextUtil.hexString(digest.digest(source.getBytes("UTF-8")));
	}
}