TransformationIteratorTests.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.test.utility.iterators;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.NoSuchElementException;

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

import org.eclipse.persistence.tools.workbench.utility.Transformer;
import org.eclipse.persistence.tools.workbench.utility.iterators.TransformationIterator;

public class TransformationIteratorTests extends TestCase {

    public static Test suite() {
        return new TestSuite(TransformationIteratorTests.class);
    }

    public TransformationIteratorTests(String name) {
        super(name);
    }

    public void testHasNext() {
        int i = 0;
        for (Iterator stream = this.buildIterator(); stream.hasNext(); ) {
            stream.next();
            i++;
        }
        assertEquals(8, i);
    }

    public void testInnerHasNext() {
        int i = 0;
        for (Iterator stream = this.buildInnerIterator(); stream.hasNext(); ) {
            stream.next();
            i++;
        }
        assertEquals(8, i);
    }

    public void testNext() {
        int i = 0;
        for (Iterator stream = this.buildIterator(); stream.hasNext(); ) {
            assertEquals("bogus transformation", ++i, ((Integer) stream.next()).intValue());
        }
    }

    public void testInnerNext() {
        int i = 0;
        for (Iterator stream = this.buildInnerIterator(); stream.hasNext(); ) {
            assertEquals("bogus transformation", ++i, ((Integer) stream.next()).intValue());
        }
    }

    public void testRemove() {
        Collection c = this.buildCollection();
        for (Iterator stream = this.buildInnerTransformationIterator(c.iterator()); stream.hasNext(); ) {
            if (((Integer) stream.next()).intValue() == 3) {
                stream.remove();
            }
        }
        assertEquals("nothing removed", this.buildCollection().size() - 1, c.size());
        assertFalse("element still in collection", c.contains("333"));
        assertTrue("wrong element removed", c.contains("22"));
    }

    public void testInnerRemove() {
        Collection c = this.buildCollection();
        for (Iterator stream = this.buildTransformationIterator(c.iterator(), this.buildTransformer()); stream.hasNext(); ) {
            if (((Integer) stream.next()).intValue() == 3) {
                stream.remove();
            }
        }
        assertEquals("nothing removed", this.buildCollection().size() - 1, c.size());
        assertFalse("element still in collection", c.contains("333"));
        assertTrue("wrong element removed", c.contains("22"));
    }

    public void testNoSuchElementException() {
        boolean exCaught = false;
        Iterator stream = this.buildIterator();
        Integer integer = null;
        while (stream.hasNext()) {
            integer = (Integer) stream.next();
        }
        try {
            integer = (Integer) stream.next();
        } catch (NoSuchElementException ex) {
            exCaught = true;
        }
        assertTrue("NoSuchElementException not thrown: " + integer, exCaught);
    }

    public void testUnsupportedOperationException() {
        boolean exCaught = false;
        for (Iterator stream = this.buildUnmodifiableIterator(); stream.hasNext(); ) {
            int i = ((Integer) stream.next()).intValue();
            if (i == 3) {
                try {
                    stream.remove();
                } catch (UnsupportedOperationException ex) {
                    exCaught = true;
                }
            }
        }
        assertTrue("UnsupportedOperationException not thrown", exCaught);
    }

    public void testIllegalStateException() {
        boolean exCaught = false;
        try {
            this.buildIterator().remove();
        } catch (IllegalStateException ex) {
            exCaught = true;
        }
        assertTrue("IllegalStateException not thrown", exCaught);
    }

    private Iterator buildIterator() {
        return this.buildTransformationIterator(this.buildNestedIterator(), this.buildTransformer());
    }

    private Iterator buildInnerIterator() {
        return this.buildInnerTransformationIterator(this.buildNestedIterator());
    }

    private Iterator buildUnmodifiableIterator() {
        return this.buildTransformationIterator(this.buildUnmodifiableNestedIterator(), this.buildTransformer());
    }

    private Iterator buildTransformationIterator(Iterator nestedIterator, Transformer transformer) {
        return new TransformationIterator(nestedIterator, transformer);
    }

    private Transformer buildTransformer() {
        // transform each string into an integer with a value of the string's length
        return new Transformer() {
            public Object transform(Object next) {
                return new Integer(((String) next).length());
            }
        };
    }

    private Iterator buildInnerTransformationIterator(Iterator nestedIterator) {
        // transform each string into an integer with a value of the string's length
        return new TransformationIterator(nestedIterator) {
            protected Object transform(Object next) {
                return new Integer(((String) next).length());
            }
        };
    }

    private Iterator buildNestedIterator() {
        return this.buildCollection().iterator();
    }

    private Iterator buildUnmodifiableNestedIterator() {
        return this.buildUnmodifiableCollection().iterator();
    }

    private Collection buildCollection() {
        Collection c = new ArrayList();
        c.add("1");
        c.add("22");
        c.add("333");
        c.add("4444");
        c.add("55555");
        c.add("666666");
        c.add("7777777");
        c.add("88888888");
        return c;
    }

    private Collection buildUnmodifiableCollection() {
        return Collections.unmodifiableCollection(this.buildCollection());
    }

}