testtransformerutils.java

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/*
 *  Copyright 2001-2004 The Apache Software Foundation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.apache.commons.collections;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import junit.framework.Test;
import junit.framework.TestSuite;
import junit.textui.TestRunner;

import org.apache.commons.collections.functors.ConstantTransformer;
import org.apache.commons.collections.functors.NOPTransformer;

/**
 * Tests the org.apache.commons.collections.TransformerUtils class.
 * 
 * @since Commons Collections 3.0
 * @version $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
 *
 * @author Stephen Colebourne
 * @author James Carman
 */
public class TestTransformerUtils extends junit.framework.TestCase {

    private static final Object cObject = new Object();
    private static final Object cString = "Hello";
    private static final Object cInteger = new Integer(6);

    /**
     * Construct
     */
    public TestTransformerUtils(String name) {
        super(name);
    }

    /**
     * Main.
     * @param args
     */    
    public static void main(String[] args) {
        TestRunner.run(suite());
    }

    /**
     * Return class as a test suite.
     */
    public static Test suite() {
        return new TestSuite(TestTransformerUtils.class);
    }

    /**
     * Set up instance variables required by this test case.
     */
    public void setUp() {
    }

    /**
     * Tear down instance variables required by this test case.
     */
    public void tearDown() {
    }

    // exceptionTransformer
    //------------------------------------------------------------------

    public void testExceptionTransformer() {
        assertNotNull(TransformerUtils.exceptionTransformer());
        assertSame(TransformerUtils.exceptionTransformer(), TransformerUtils.exceptionTransformer());
        try {
            TransformerUtils.exceptionTransformer().transform(null);
        } catch (FunctorException ex) {
            try {
                TransformerUtils.exceptionTransformer().transform(cString);
            } catch (FunctorException ex2) {
                return;
            }
        }
        fail();
    }
    
    // nullTransformer
    //------------------------------------------------------------------

    public void testNullTransformer() {
        assertNotNull(TransformerUtils.nullTransformer());
        assertSame(TransformerUtils.nullTransformer(), TransformerUtils.nullTransformer());
        assertEquals(null, TransformerUtils.nullTransformer().transform(null));
        assertEquals(null, TransformerUtils.nullTransformer().transform(cObject));
        assertEquals(null, TransformerUtils.nullTransformer().transform(cString));
        assertEquals(null, TransformerUtils.nullTransformer().transform(cInteger));
    }

    // nopTransformer
    //------------------------------------------------------------------

    public void testNopTransformer() {
        assertNotNull(TransformerUtils.nullTransformer());
        assertSame(TransformerUtils.nullTransformer(), TransformerUtils.nullTransformer());
        assertEquals(null, TransformerUtils.nopTransformer().transform(null));
        assertEquals(cObject, TransformerUtils.nopTransformer().transform(cObject));
        assertEquals(cString, TransformerUtils.nopTransformer().transform(cString));
        assertEquals(cInteger, TransformerUtils.nopTransformer().transform(cInteger));
    }

    // constantTransformer
    //------------------------------------------------------------------

    public void testConstantTransformer() {
        assertEquals(cObject, TransformerUtils.constantTransformer(cObject).transform(null));
        assertEquals(cObject, TransformerUtils.constantTransformer(cObject).transform(cObject));
        assertEquals(cObject, TransformerUtils.constantTransformer(cObject).transform(cString));
        assertEquals(cObject, TransformerUtils.constantTransformer(cObject).transform(cInteger));
        assertSame(ConstantTransformer.NULL_INSTANCE, TransformerUtils.constantTransformer(null));
    }

    // cloneTransformer
    //------------------------------------------------------------------

    public void testCloneTransformer() {
        assertEquals(null, TransformerUtils.cloneTransformer().transform(null));
        assertEquals(cString, TransformerUtils.cloneTransformer().transform(cString));
        assertEquals(cInteger, TransformerUtils.cloneTransformer().transform(cInteger));
        try {
            assertEquals(cObject, TransformerUtils.cloneTransformer().transform(cObject));
        } catch (IllegalArgumentException ex) {
            return;
        }
        fail();
    }

    // mapTransformer
    //------------------------------------------------------------------

    public void testMapTransformer() {
        Map map = new HashMap();
        map.put(null, new Integer(0));
        map.put(cObject, new Integer(1));
        map.put(cString, new Integer(2));
        assertEquals(new Integer(0), TransformerUtils.mapTransformer(map).transform(null));
        assertEquals(new Integer(1), TransformerUtils.mapTransformer(map).transform(cObject));
        assertEquals(new Integer(2), TransformerUtils.mapTransformer(map).transform(cString));
        assertEquals(null, TransformerUtils.mapTransformer(map).transform(cInteger));
        assertSame(ConstantTransformer.NULL_INSTANCE, TransformerUtils.mapTransformer(null));
    }

    // commandTransformer
    //------------------------------------------------------------------

    public void testExecutorTransformer() {
        assertEquals(null, TransformerUtils.asTransformer(ClosureUtils.nopClosure()).transform(null));
        assertEquals(cObject, TransformerUtils.asTransformer(ClosureUtils.nopClosure()).transform(cObject));
        assertEquals(cString, TransformerUtils.asTransformer(ClosureUtils.nopClosure()).transform(cString));
        assertEquals(cInteger, TransformerUtils.asTransformer(ClosureUtils.nopClosure()).transform(cInteger));
        try {
            TransformerUtils.asTransformer((Closure) null);
        } catch (IllegalArgumentException ex) {
            return;
        }
        fail();
    }

    // predicateTransformer
    //------------------------------------------------------------------

    public void testPredicateTransformer() {
        assertEquals(Boolean.TRUE, TransformerUtils.asTransformer(PredicateUtils.truePredicate()).transform(null));
        assertEquals(Boolean.TRUE, TransformerUtils.asTransformer(PredicateUtils.truePredicate()).transform(cObject));
        assertEquals(Boolean.TRUE, TransformerUtils.asTransformer(PredicateUtils.truePredicate()).transform(cString));
        assertEquals(Boolean.TRUE, TransformerUtils.asTransformer(PredicateUtils.truePredicate()).transform(cInteger));
        try {
            TransformerUtils.asTransformer((Predicate) null);
        } catch (IllegalArgumentException ex) {
            return;
        }
        fail();
    }

    // factoryTransformer
    //------------------------------------------------------------------

    public void testFactoryTransformer() {
        assertEquals(null, TransformerUtils.asTransformer(FactoryUtils.nullFactory()).transform(null));
        assertEquals(null, TransformerUtils.asTransformer(FactoryUtils.nullFactory()).transform(cObject));
        assertEquals(null, TransformerUtils.asTransformer(FactoryUtils.nullFactory()).transform(cString));
        assertEquals(null, TransformerUtils.asTransformer(FactoryUtils.nullFactory()).transform(cInteger));
        try {
            TransformerUtils.asTransformer((Factory) null);
        } catch (IllegalArgumentException ex) {
            return;
        }
        fail();
    }

    // chainedTransformer
    //------------------------------------------------------------------

    public void testChainedTransformer() {
        Transformer a = TransformerUtils.constantTransformer("A");
        Transformer b = TransformerUtils.constantTransformer("B");
        
        assertEquals("A", TransformerUtils.chainedTransformer(b, a).transform(null));
        assertEquals("B", TransformerUtils.chainedTransformer(a, b).transform(null));
        assertEquals("A", TransformerUtils.chainedTransformer(new Transformer[] {b, a}).transform(null));