/*
* 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.
*/
package org.apache.pig.builtin;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.pig.builtin.SUBTRACT;
import org.apache.pig.data.BagFactory;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.Tuple;
import org.apache.pig.data.TupleFactory;
import org.junit.Test;
public class TestSUBTRACT {
private static SUBTRACT subtract = new SUBTRACT();
@Test
public void testSubtractBags() throws IOException {
Tuple input = TupleFactory.getInstance().newTuple(2);
input.set(0, bag(tuple("item1"), tuple("item2"), tuple("item3")));
input.set(1, bag(tuple("item1"), tuple("item4"), tuple("item5")));
assertBagContainsOnly(subtract.exec(input), tuple("item2"), tuple("item3"));
// Note that "item2" which appears several times in first bag, is not in the resulting bag
input.set(0, bag(tuple("item1"), tuple("item2"), tuple("item2"), tuple("item3"), tuple("item4")));
input.set(1, bag(tuple("item1"), tuple("item2"), tuple("item3")));
assertBagContainsOnly(subtract.exec(input), tuple("item4"));
input.set(0, bag(tuple("item1"), tuple("item2"), tuple("item3"), tuple("item4")));
input.set(1, bag(tuple("item2"), tuple("item3"), tuple("item1")));
assertBagContainsOnly(subtract.exec(input), tuple("item4"));
input.set(0, bag(tuple("item1"), tuple("item2"), tuple("item3")));
input.set(1, bag(tuple("item1"), tuple("item2"), tuple("item3"), tuple("item4")));
assertEquals(0, subtract.exec(input).size());
input.set(0, bag(tuple("item1"), tuple("item2"), tuple("item3")));
input.set(1, bag(tuple("item1"), tuple("item2"), tuple("item3")));
assertEquals(0, subtract.exec(input).size());
input.set(0, bag());
input.set(1, bag(tuple("item1"), tuple("item2"), tuple("item3")));
assertEquals(0, subtract.exec(input).size());
// null treated like empty bag
input.set(0, null);
input.set(1, bag(tuple("item1"), tuple("item2"), tuple("item3")));
assertEquals(0, subtract.exec(input).size());
input.set(0, bag(tuple("item1"), tuple("item2"), tuple("item3")));
input.set(1, bag());
assertBagContainsOnly(subtract.exec(input), tuple("item1"), tuple("item2"), tuple("item3"));
// null treated like empty bag
input.set(0, bag(tuple("item1"), tuple("item2"), tuple("item3")));
input.set(1, null);
assertBagContainsOnly(subtract.exec(input), tuple("item1"), tuple("item2"), tuple("item3"));
}
@Test
public void testShouldThrowAnIOExceptionAsInputDoesNotContainDataBagOnly() {
Tuple input = TupleFactory.getInstance().newTuple(2);
try {
input.set(0, "2012/05/05");
input.set(1, bag());
subtract.exec(input);
fail("IOException Expected");
} catch (IOException e) {
assertEquals("Expecting input to be DataBag only but was 'String'", e.getMessage());
}
}
@Test
public void testShouldThrowAnIOExceptionAsInputDoesNotHaveTwoElements() {
Tuple input = TupleFactory.getInstance().newTuple(1);
try {
input.set(0, bag());
subtract.exec(input);
fail("IOException Expected");
} catch (IOException e) {
assertEquals("SUBTRACT expected two inputs but received 1 inputs.", e.getMessage());
}
input = TupleFactory.getInstance().newTuple(3);
try {
input.set(0, bag());
input.set(1, bag());
input.set(2, bag());
subtract.exec(input);
fail("IOException Expected");
} catch (IOException e) {
assertEquals("SUBTRACT expected two inputs but received 3 inputs.", e.getMessage());
}
}
// utility assertion method
/**
* Checks that given {@link DataBag} contains only the given {@link Tuple}s.
* @param bag the {@link DataBag} to check
* @param tuples the {@link Tuple}s expected in given {@link DataBag}
*/
private static void assertBagContainsOnly(DataBag bag, Tuple... tuples) {
Iterator<Tuple> bagTuplesIterator = bag.iterator();
List<Tuple> bagTuplesList = new ArrayList<Tuple>();
while (bagTuplesIterator.hasNext()) {
bagTuplesList.add(bagTuplesIterator.next());
}
assertEquals("Wrong bag size", tuples.length, bagTuplesList.size());
// bag has same size as given tuples, let's see if each tuple is in bag.
for (Tuple tuple : tuples) {
assertTrue("Tuple not found in bag " + tuple, bagTuplesList.contains(tuple));
}
}
// utility methods to build bags, tuples and list
private static <E> List<E> list(E... elements) {
if (elements == null) {
return new ArrayList<E>();
}
List<E> list = new ArrayList<E>();
for (E element : elements) {
list.add(element);
}
return list;
}
private static Tuple tuple(Object... elements) {
if (elements == null) {
return TupleFactory.getInstance().newTuple();
}
return TupleFactory.getInstance().newTuple(list(elements));
}
private static DataBag bag(Tuple... tuples) {
if (tuples == null) {
return BagFactory.getInstance().newDefaultBag();
}
return BagFactory.getInstance().newDefaultBag(list(tuples));
}
}