taverna-scufl2-api/src/test/java/org/apache/taverna/scufl2/api/impl/TestIterableComparator.java

package org.apache.taverna.scufl2.api.impl;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */


import static org.junit.Assert.*;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import org.apache.taverna.scufl2.api.impl.IterableComparator;
import org.junit.Test;

public class TestIterableComparator {
	@SuppressWarnings("serial")
	public class ReverseComparableList extends ArrayList<String> implements Comparable<ReverseComparableList> {
		public boolean called = false;
		public ReverseComparableList(String... items) {
			addAll(Arrays.asList(items));
		}

		@Override
		public int compareTo(ReverseComparableList o) {
			called = true;
			// Reverse string order
			return o.toString().compareTo(this.toString());
		}
	}

	@Test
	public void listCompare() throws Exception {
		List<List<String>> values = Arrays.asList(Arrays.asList("x", "y"),
				Arrays.asList("a", "b", "c", "d", "e"),
				Arrays.asList("a", "b", "c", "d"),
				Arrays.asList("a", "b", null, "d"));

		List<List<String>> sortedValues = Arrays.asList(
				Arrays.asList("a", "b", null, "d"), // null < c
				Arrays.asList("a", "b", "c", "d"), // shorter list (but matching
													// prefix)
				Arrays.asList("a", "b", "c", "d", "e"), Arrays.asList("x", "y") // "x"
																				// >
																				// "a"
				);

		Collections.sort(values, new IterableComparator());
		assertEquals(sortedValues, values);
	}

	@Test
	public void nestedListCompare() throws Exception {
		List<List<List<String>>> values = Arrays.asList(
				Arrays.asList(Arrays.asList("x", "y", "z"),
						Arrays.asList("1", "2", "3"), Arrays.asList("extra")),
				Arrays.asList(Arrays.asList("x", "y", "z"),
						Arrays.asList("1", "2", "3")));

		List<List<List<String>>> sortedValues = Arrays.asList(
				Arrays.asList(Arrays.asList("x", "y", "z"),
						Arrays.asList("1", "2", "3")),
				Arrays.asList(Arrays.asList("x", "y", "z"),
						Arrays.asList("1", "2", "3"), Arrays.asList("extra")));

		Collections.sort(values, new IterableComparator());
		assertEquals(sortedValues, values);
	}

	@SuppressWarnings({ "rawtypes", "unchecked" })
	@Test(expected = ClassCastException.class)
	public void intsAndStrings() throws Exception {
		List<Integer> intList = Arrays.asList(1, 2, 3);
		List<String> strList = Arrays.asList("x", "y");
		List values = Arrays.asList(intList, strList);
		Collections.sort(values, new IterableComparator());
	}
}