CollatingIteratorTest.java
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* 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
*
* https://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,
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* See the License for the specific language governing permissions and
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package org.apache.commons.collections4.iterators;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertSame;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import org.apache.commons.collections4.comparators.ComparableComparator;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
/**
* Unit test suite for {@link CollatingIterator}.
*/
@SuppressWarnings("boxing")
class CollatingIteratorTest extends AbstractIteratorTest<Integer> {
private Comparator<Integer> comparator;
private ArrayList<Integer> evens;
private ArrayList<Integer> odds;
private ArrayList<Integer> fib;
@Override
public CollatingIterator<Integer> makeEmptyIterator() {
return new CollatingIterator<>(comparator);
}
@Override
public CollatingIterator<Integer> makeObject() {
final CollatingIterator<Integer> iter = new CollatingIterator<>(comparator);
iter.addIterator(evens.iterator());
iter.addIterator(odds.iterator());
iter.addIterator(fib.iterator());
return iter;
}
@BeforeEach
public void setUp() throws Exception {
comparator = new ComparableComparator<>();
evens = new ArrayList<>();
odds = new ArrayList<>();
for (int i = 0; i < 20; i++) {
if (0 == i % 2) {
evens.add(i);
} else {
odds.add(i);
}
}
fib = new ArrayList<>();
fib.add(1);
fib.add(1);
fib.add(2);
fib.add(3);
fib.add(5);
fib.add(8);
fib.add(13);
fib.add(21);
}
@Test
void testGetSetComparator() {
final CollatingIterator<Integer> iter = new CollatingIterator<>();
assertNull(iter.getComparator());
iter.setComparator(comparator);
assertSame(comparator, iter.getComparator());
iter.setComparator(null);
assertNull(iter.getComparator());
}
@Test
void testIterateEven() {
final CollatingIterator<Integer> iter = new CollatingIterator<>(comparator);
iter.addIterator(evens.iterator());
for (final Integer even : evens) {
assertTrue(iter.hasNext());
assertEquals(even, iter.next());
assertEquals(0, iter.getIteratorIndex());
}
assertFalse(iter.hasNext());
}
@Test
void testIterateEvenEven() {
final CollatingIterator<Integer> iter = new CollatingIterator<>(comparator);
iter.addIterator(evens.iterator());
iter.addIterator(evens.iterator());
for (final Integer even : evens) {
assertTrue(iter.hasNext());
assertEquals(even, iter.next());
assertEquals(0, iter.getIteratorIndex());
assertTrue(iter.hasNext());
assertEquals(even, iter.next());
assertEquals(1, iter.getIteratorIndex());
}
assertFalse(iter.hasNext());
}
@Test
void testIterateEvenOdd() {
final CollatingIterator<Integer> iter = new CollatingIterator<>(comparator, evens.iterator(), odds.iterator());
for (int i = 0; i < 20; i++) {
assertTrue(iter.hasNext());
assertEquals(Integer.valueOf(i), iter.next());
assertEquals(i % 2, iter.getIteratorIndex());
}
assertFalse(iter.hasNext());
}
@Test
void testIterateFibEvenOdd() {
final CollatingIterator<Integer> iter = new CollatingIterator<>(comparator);
iter.addIterator(fib.iterator());
iter.addIterator(evens.iterator());
iter.addIterator(odds.iterator());
assertEquals(Integer.valueOf(0), iter.next()); // even 0
assertEquals(1, iter.getIteratorIndex());
assertEquals(Integer.valueOf(1), iter.next()); // fib 1
assertEquals(0, iter.getIteratorIndex());
assertEquals(Integer.valueOf(1), iter.next()); // fib 1
assertEquals(0, iter.getIteratorIndex());
assertEquals(Integer.valueOf(1), iter.next()); // odd 1
assertEquals(2, iter.getIteratorIndex());
assertEquals(Integer.valueOf(2), iter.next()); // fib 2
assertEquals(0, iter.getIteratorIndex());
assertEquals(Integer.valueOf(2), iter.next()); // even 2
assertEquals(1, iter.getIteratorIndex());
assertEquals(Integer.valueOf(3), iter.next()); // fib 3
assertEquals(0, iter.getIteratorIndex());
assertEquals(Integer.valueOf(3), iter.next()); // odd 3
assertEquals(2, iter.getIteratorIndex());
assertEquals(Integer.valueOf(4), iter.next()); // even 4
assertEquals(1, iter.getIteratorIndex());
assertEquals(Integer.valueOf(5), iter.next()); // fib 5
assertEquals(0, iter.getIteratorIndex());
assertEquals(Integer.valueOf(5), iter.next()); // odd 5
assertEquals(2, iter.getIteratorIndex());
assertEquals(Integer.valueOf(6), iter.next()); // even 6
assertEquals(1, iter.getIteratorIndex());
assertEquals(Integer.valueOf(7), iter.next()); // odd 7
assertEquals(2, iter.getIteratorIndex());
assertEquals(Integer.valueOf(8), iter.next()); // fib 8
assertEquals(0, iter.getIteratorIndex());
assertEquals(Integer.valueOf(8), iter.next()); // even 8
assertEquals(1, iter.getIteratorIndex());
assertEquals(Integer.valueOf(9), iter.next()); // odd 9
assertEquals(2, iter.getIteratorIndex());
assertEquals(Integer.valueOf(10), iter.next()); // even 10
assertEquals(1, iter.getIteratorIndex());
assertEquals(Integer.valueOf(11), iter.next()); // odd 11
assertEquals(2, iter.getIteratorIndex());
assertEquals(Integer.valueOf(12), iter.next()); // even 12
assertEquals(1, iter.getIteratorIndex());
assertEquals(Integer.valueOf(13), iter.next()); // fib 13
assertEquals(0, iter.getIteratorIndex());
assertEquals(Integer.valueOf(13), iter.next()); // odd 13
assertEquals(2, iter.getIteratorIndex());
assertEquals(Integer.valueOf(14), iter.next()); // even 14
assertEquals(1, iter.getIteratorIndex());
assertEquals(Integer.valueOf(15), iter.next()); // odd 15
assertEquals(2, iter.getIteratorIndex());
assertEquals(Integer.valueOf(16), iter.next()); // even 16
assertEquals(1, iter.getIteratorIndex());
assertEquals(Integer.valueOf(17), iter.next()); // odd 17
assertEquals(2, iter.getIteratorIndex());
assertEquals(Integer.valueOf(18), iter.next()); // even 18
assertEquals(1, iter.getIteratorIndex());
assertEquals(Integer.valueOf(19), iter.next()); // odd 19
assertEquals(2, iter.getIteratorIndex());
assertEquals(Integer.valueOf(21), iter.next()); // fib 21
assertEquals(0, iter.getIteratorIndex());
assertFalse(iter.hasNext());
}
@Test
void testIterateOddEven() {
final CollatingIterator<Integer> iter = new CollatingIterator<>(comparator, odds.iterator(), evens.iterator());
for (int i = 0; i < 20; i++) {
assertTrue(iter.hasNext());
assertEquals(Integer.valueOf(i), iter.next());
assertEquals(i % 2 == 0 ? 1 : 0, iter.getIteratorIndex());
}
assertFalse(iter.hasNext());
}
@Test
void testNullComparator() {
final List<Integer> l1 = Arrays.asList(1, 3, 5);
final List<Integer> l2 = Arrays.asList(2, 4, 6);
final CollatingIterator<Integer> collatingIterator1 = new CollatingIterator<>(null, l1.iterator(), l2.iterator());
assertThrows(NullPointerException.class, collatingIterator1::next, "You must invoke setComparator");
int i = 0;
final CollatingIterator<Integer> collatingIterator2 = new CollatingIterator<>(null, l1.iterator(), l2.iterator());
collatingIterator2.setComparator(new ComparableComparator<>());
for (; collatingIterator2.hasNext(); i++) {
final Integer n = collatingIterator2.next();
assertEquals((int) n, i + 1, "wrong order");
}
assertEquals(i, l1.size() + l2.size(), "wrong size");
}
@Test
void testRemoveFromDouble() {
final CollatingIterator<Integer> iter = new CollatingIterator<>(comparator);
iter.addIterator(evens.iterator());
iter.addIterator(odds.iterator());
int expectedSize = evens.size() + odds.size();
while (iter.hasNext()) {
final Object o = iter.next();
final Integer val = (Integer) o;
if (val.intValue() % 4 == 0 || val.intValue() % 3 == 0) {
expectedSize--;
iter.remove();
}
}
assertEquals(expectedSize, evens.size() + odds.size());
}
@Test
void testRemoveFromSingle() {
final CollatingIterator<Integer> iter = new CollatingIterator<>(comparator);
iter.addIterator(evens.iterator());
int expectedSize = evens.size();
while (iter.hasNext()) {
final Object o = iter.next();
final Integer val = (Integer) o;
if (val.intValue() % 4 == 0) {
expectedSize--;
iter.remove();
}
}
assertEquals(expectedSize, evens.size());
}
}