/*
 *  TestFilterIterator.java
 *
 * Created on September 2, 2001, 4:07 PM
 */

package org.apache.commons.collections;

import junit.framework.TestCase;
import junit.framework.TestSuite;
import junit.framework.Test;
import java.util.NoSuchElementException;


/**
 *
 * @author  Jan Sorensen
 */
public class TestFilterIterator extends TestCase {

    /** Creates new TestFilterIterator */
    public TestFilterIterator(String name) {
	super(name);
    }

    private String[] array;
    private FilterIterator iterator;
    /**
     * Set up instance variables required by this test case.
     */
    public void setUp() {
        array = new String[] { "a", "b", "c" };
        initIterator();
    }
    
    /**
     * Tear down instance variables required by this test case.
     */
    public void tearDown() {
        iterator = null;
    }
    
    /**
     * Return the tests included in this test suite.
     */
    public static Test suite() {
        return (new TestSuite(TestFilterIterator.class));
    }
    
    public void testRepeatedHasNext() {
        for (int i = 0; i <= array.length; i++) {
            assertTrue(iterator.hasNext());
        }
    }
    
    public void testRepeatedNext() {
        for (int i = 0; i < array.length; i++)
            iterator.next();
        verifyNoMoreElements();
    }
         
    public void testReturnValues() {
        verifyElementsInPredicate(new String[0]);
        verifyElementsInPredicate(new String[] { "a" });
        verifyElementsInPredicate(new String[] { "b" });
        verifyElementsInPredicate(new String[] { "c" });
        verifyElementsInPredicate(new String[] { "a", "b" });
        verifyElementsInPredicate(new String[] { "a", "c" });
        verifyElementsInPredicate(new String[] { "b", "c" });
        verifyElementsInPredicate(new String[] { "a", "b", "c" });
    }
    
    private void verifyNoMoreElements() {
        assertTrue(!iterator.hasNext());
        try {
            iterator.next();
            fail("NoSuchElementException expected");
        }
        catch (NoSuchElementException e) {
            // success
        }    
    }
    
    private void verifyElementsInPredicate(final String[] elements) {
        Predicate pred = new Predicate() {
            public boolean evaluate(Object x) {
                for (int i = 0; i < elements.length; i++)
                    if (elements[i].equals(x))
                        return true;
                return false;
            }
        };
        initIterator();
        iterator.setPredicate(pred);
        for (int i = 0; i < elements.length; i++) {
            String s = (String)iterator.next();
            assertEquals(elements[i], s);
            assertTrue(i == elements.length - 1 ? !iterator.hasNext() : iterator.hasNext());
        }
        verifyNoMoreElements();
    }
        
    private void initIterator() {
        iterator = new FilterIterator(new ArrayIterator(array));
        Predicate pred = new Predicate() { 
            public boolean evaluate(Object x) { return true; }
        };
        iterator.setPredicate(pred);        
    }
}