LineFunction2DTests.java

/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2011, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
 * Other names may be trademarks of their respective owners.]
 *
 * ------------------------
 * LineFunction2DTests.java
 * ------------------------
 * (C) Copyright 2009, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 28-May-2009 : Version 1 (DG);
 *
 */

package org.jfree.data.function.junit;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

import org.jfree.data.function.LineFunction2D;

/**
 * Tests for the {@link LineFunction2D} class.
 */
public class LineFunction2DTests extends TestCase {

    /**
     * Returns the tests as a test suite.
     *
     * @return The test suite.
     */
    public static Test suite() {
        return new TestSuite(LineFunction2DTests.class);
    }

    /**
     * Constructs a new set of tests.
     *
     * @param name  the name of the tests.
     */
    public LineFunction2DTests(String name) {
        super(name);
    }

    private static final double EPSILON = 0.000000001;

    /**
     * Some tests for the constructor.
     */
    public void testConstructor() {
        LineFunction2D f = new LineFunction2D(1.0, 2.0);
        assertEquals(1.0, f.getIntercept(), EPSILON);
        assertEquals(2.0, f.getSlope(), EPSILON);
    }



    /**
     * For datasets, the equals() method just checks keys and values.
     */
    public void testEquals() {
        LineFunction2D f1 = new LineFunction2D(1.0, 2.0);
        LineFunction2D f2 = new LineFunction2D(1.0, 2.0);
        assertTrue(f1.equals(f2));
        f1 = new LineFunction2D(2.0, 3.0);
        assertFalse(f1.equals(f2));
        f2 = new LineFunction2D(2.0, 3.0);
        assertTrue(f1.equals(f2));
    }

    /**
     * Serialize an instance, restore it, and check for equality.
     */
    public void testSerialization() {
        LineFunction2D f1 = new LineFunction2D(1.0, 2.0);
        LineFunction2D f2 = null;

        try {
            ByteArrayOutputStream buffer = new ByteArrayOutputStream();
            ObjectOutput out = new ObjectOutputStream(buffer);
            out.writeObject(f1);
            out.close();

            ObjectInput in = new ObjectInputStream(new ByteArrayInputStream(
                    buffer.toByteArray()));
            f2 = (LineFunction2D) in.readObject();
            in.close();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        assertEquals(f1, f2);
    }

    /**
     * Objects that are equal should have the same hash code otherwise FindBugs
     * will tell on us...
     */
    public void testHashCode() {
        LineFunction2D f1 = new LineFunction2D(1.0, 2.0);
        LineFunction2D f2 = new LineFunction2D(1.0, 2.0);
        assertEquals(f1.hashCode(), f2.hashCode());
    }

}