/*
* Copyright (C) 2007 Google Inc.
*
* 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 com.google.common.collect;
import com.google.common.base.Function;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import static com.google.common.collect.Iterators.get;
import static com.google.common.collect.Iterators.getLast;
import static com.google.common.collect.Lists.newArrayList;
import com.google.common.collect.testing.IteratorFeature;
import static com.google.common.collect.testing.IteratorFeature.MODIFIABLE;
import static com.google.common.collect.testing.IteratorFeature.UNMODIFIABLE;
import com.google.common.collect.testing.IteratorTester;
import com.google.common.collect.testing.ListTestSuiteBuilder;
import com.google.common.collect.testing.TestStringListGenerator;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.ListFeature;
import static com.google.common.testing.junit3.JUnitAsserts.assertContentsInOrder;
import com.google.common.testutils.NullPointerTester;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import java.util.Arrays;
import static java.util.Arrays.asList;
import java.util.Collection;
import java.util.Collections;
import static java.util.Collections.singleton;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.RandomAccess;
import java.util.Set;
import java.util.Vector;
/**
* Unit test for {@code Iterators}.
*
* @author Kevin Bourrillion
*/
public class IteratorsTest extends TestCase {
public static Test suite() {
TestSuite suite = new TestSuite(IteratorsTest.class.getSimpleName());
suite.addTest(testsForRemoveAllAndRetainAll());
suite.addTestSuite(IteratorsTest.class);
return suite;
}
public void testEmptyIterator() {
Iterator<String> iterator = Iterators.emptyIterator();
assertFalse(iterator.hasNext());
try {
iterator.next();
fail("no exception thrown");
} catch (NoSuchElementException expected) {
}
try {
iterator.remove();
fail("no exception thrown");
} catch (UnsupportedOperationException expected) {
}
}
public void testSize0() {
Iterator<String> iterator = Iterators.emptyIterator();
assertEquals(0, Iterators.size(iterator));
}
public void testSize1() {
Iterator<Integer> iterator = Collections.singleton(0).iterator();
assertEquals(1, Iterators.size(iterator));
}
public void testSize_partiallyConsumed() {
Iterator<Integer> iterator = asList(1, 2, 3, 4, 5).iterator();
iterator.next();
iterator.next();
assertEquals(3, Iterators.size(iterator));
}
public void test_contains_nonnull_yes() {
Iterator<String> set = asList("a", null, "b").iterator();
assertTrue(Iterators.contains(set, "b"));
}
public void test_contains_nonnull_no() {
Iterator<String> set = asList("a", "b").iterator();
assertFalse(Iterators.contains(set, "c"));
}
public void test_contains_null_yes() {
Iterator<String> set = asList("a", null, "b").iterator();
assertTrue(Iterators.contains(set, null));
}
public void test_contains_null_no() {
Iterator<String> set = asList("a", "b").iterator();
assertFalse(Iterators.contains(set, null));
}
public void testGetOnlyElement_noDefault_valid() {
Iterator<String> iterator = Collections.singletonList("foo").iterator();
assertEquals("foo", Iterators.getOnlyElement(iterator));
}
public void testGetOnlyElement_noDefault_empty() {
Iterator<String> iterator = Iterators.emptyIterator();
try {
Iterators.getOnlyElement(iterator);
fail();
} catch (NoSuchElementException expected) {
}
}
public void testGetOnlyElement_noDefault_moreThanOneLessThanFiveElements() {
Iterator<String> iterator = asList("one", "two").iterator();
try {
Iterators.getOnlyElement(iterator);
fail();
} catch (IllegalArgumentException expected) {
assertEquals("expected one element but was: <one, two>",
expected.getMessage());
}
}
public void testGetOnlyElement_noDefault_fiveElements() {
Iterator<String> iterator =
asList("one", "two", "three", "four", "five").iterator();
try {
Iterators.getOnlyElement(iterator);
fail();
} catch (IllegalArgumentException expected) {
assertEquals("expected one element but was: "
+ "<one, two, three, four, five>",
expected.getMessage());
}
}
public void testGetOnlyElement_noDefault_moreThanFiveElements() {
Iterator<String> iterator =
asList("one", "two", "three", "four", "five", "six").iterator();
try {
Iterators.getOnlyElement(iterator);
fail();
} catch (IllegalArgumentException expected) {
assertEquals("expected one element but was: "
+ "<one, two, three, four, five, ...>",
expected.getMessage());
}
}
public void testGetOnlyElement_withDefault_singleton() {
Iterator<String> iterator = Collections.singletonList("foo").iterator();
assertEquals("foo", Iterators.getOnlyElement(iterator, "bar"));
}
public void testGetOnlyElement_withDefault_empty() {
Iterator<String> iterator = Iterators.emptyIterator();
assertEquals("bar", Iterators.getOnlyElement(iterator, "bar"));
}
public void testGetOnlyElement_withDefault_empty_null() {
Iterator<String> iterator = Iterators.emptyIterator();
assertNull(Iterators.getOnlyElement(iterator, null));
}
public void testGetOnlyElement_withDefault_two() {
Iterator<String> iterator = asList("foo", "bar").iterator();
try {
Iterators.getOnlyElement(iterator, "x");
fail();
} catch (IllegalArgumentException expected) {
assertEquals("expected one element but was: <foo, bar>",
expected.getMessage());
}
}
public void testToArrayEmpty() {
Iterator<String> iterator = Collections.<String>emptyList().iterator();
String[] array = Iterators.toArray(iterator, String.class);
assertTrue(Arrays.equals(new String[0], array));
}
public void testToArraySingleton() {
Iterator<String> iterator = Collections.singletonList("a").iterator();
String[] array = Iterators.toArray(iterator, String.class);
assertTrue(Arrays.equals(new String[] { "a" }, array));
}
public void testToArray() {
String[] sourceArray = new String[] {"a", "b", "c"};
Iterator<String> iterator = asList(sourceArray).iterator();
String[] newArray = Iterators.toArray(iterator, String.class);
assertTrue(Arrays.equals(sourceArray, newArray));
}
public void testFilterSimple() {
Iterator<String> unfiltered = Lists.newArrayList("foo", "bar").iterator();
Iterator<String> filtered = Iterators.filter(unfiltered,
Predicates.equalTo("foo"));
List<String> expected = Collections.singletonList("foo");
List<String> actual = Lists.newArrayList(filtered);
assertEquals(expected, actual);
}
public void testFilterNoMatch() {
Iterator<String> unfiltered = Lists.newArrayList("foo", "bar").iterator();
Iterator<String> filtered = Iterators.filter(unfiltered,
Predicates.alwaysFalse());
List<String> expected = Collections.emptyList();
List<String> actual = Lists.newArrayList(filtered);
assertEquals(expected, actual);
}
public void testFilterMatchAll() {
Iterator<String> unfiltered = Lists.newArrayList("foo", "bar").iterator();
Iterator<String> filtered = Iterators.filter(unfiltered,
Predicates.alwaysTrue());
List<String> expected = Lists.newArrayList("foo", "bar");
List<String> actual = Lists.newArrayList(filtered);
assertEquals(expected, actual);
}
public void testFilterNothing() {
Iterator<String> unfiltered = Collections.<String>emptyList().iterator();
Iterator<String> filtered = Iterators.filter(unfiltered,
new Predicate<String>() {
public boolean apply(String s) {
fail("Should never be evaluated");
return false;
}
});
List<String> expected = Collections.emptyList();
List<String> actual = Lists.newArrayList(filtered);
assertEquals(expected, actual);
}
public void testFilterUsingIteratorTester() throws Exception {
final List<Integer> list = asList(1, 2, 3, 4, 5);
final Predicate<Integer> isEven = new Predicate<Integer>() {
public boolean apply(Integer integer) {
return integer % 2 == 0;
}
};
new IteratorTester<Integer>(5, UNMODIFIABLE, asList(2, 4),
IteratorTester.KnownOrder.KNOWN_ORDER) {
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.filter(list.iterator(), isEven);
}
}.test();
}
public void testAny() {
List<String> list = Lists.newArrayList();
Predicate<String> predicate = Predicates.equalTo("pants");
assertFalse(Iterators.any(list.iterator(), predicate));
list.add("cool");
assertFalse(Iterators.any(list.iterator(), predicate));
list.add("pants");
assertTrue(Iterators.any(list.iterator(), predicate));
}
public void testAll() {
List<String> list = Lists.newArrayList();
Predicate<String> predicate = Predicates.equalTo("cool");
assertTrue(Iterators.all(list.iterator(), predicate));
list.add("cool");
assertTrue(Iterators.all(list.iterator(), predicate));
list.add("pants");
assertFalse(Iterators.all(list.iterator(), predicate));
}
public void testFind() {
Iterable<String> list = Lists.newArrayList("cool", "pants");
assertEquals("cool",
Iterators.find(list.iterator(), Predicates.equalTo("cool")));
assertEquals("pants",
Iterators.find(list.iterator(), Predicates.equalTo("pants")));
try {
Iterators.find(list.iterator(), Predicates.alwaysFalse());
fail();
} catch (NoSuchElementException e) {
}
assertEquals("cool",
Iterators.find(list.iterator(), Predicates.alwaysTrue()));
}
public void testTransform() {
Iterator<String> input = asList("1", "2", "3").iterator();
Iterator<Integer> result = Iterators.transform(input,
new Function<String, Integer>() {
public Integer apply(String from) {
return Integer.valueOf(from);
}
});
List<Integer> actual = Lists.newArrayList(result);
List<Integer> expected = asList(1, 2, 3);
assertEquals(expected, actual);
}
public void testTransformRemove() {
List<String> list = Lists.newArrayList("1", "2", "3");
Iterator<String> input = list.iterator();
Iterator<Integer> iterator = Iterators.transform(input,
new Function<String, Integer>() {
public Integer apply(String from) {
return Integer.valueOf(from);
}
});
assertEquals(Integer.valueOf(1), iterator.next());
assertEquals(Integer.valueOf(2), iterator.next());
iterator.remove();
assertEquals(asList("1", "3"), list);
}
public void testPoorlyBehavedTransform() {
Iterator<String> input = asList("1", null, "3").iterator();
Iterator<Integer> result = Iterators.transform(input,
new Function<String, Integer>() {
public Integer apply(String from) {
return Integer.valueOf(from);
}
});
result.next();
try {
result.next();
fail("Expected NFE");
} catch (NumberFormatException nfe) {
// Expected to fail.
}
}
public void testNullFriendlyTransform() {
Iterator<Integer> input = asList(1, 2, null, 3).iterator();
Iterator<String> result = Iterators.transform(input,
new Function<Integer, String>() {
public String apply(Integer from) {
return String.valueOf(from);
}
});
List<String> actual = Lists.newArrayList(result);
List<String> expected = asList("1", "2", "null", "3");
assertEquals(expected, actual);
}
public void testCycleOfEmpty() {
// "<String>" for javac 1.5.
Iterator<String> cycle = Iterators.<String>cycle();
assertFalse(cycle.hasNext());
}
public void testCycleOfOne() {
Iterator<String> cycle = Iterators.cycle("a");
for (int i = 0; i < 3; i++) {
assertTrue(cycle.hasNext());
assertEquals("a", cycle.next());
}
}
public void testCycleOfOneWithRemove() {
Iterable<String> iterable = Lists.newArrayList("a");
Iterator<String> cycle = Iterators.cycle(iterable);
assertTrue(cycle.hasNext());
assertEquals("a", cycle.next());
cycle.remove();
assertEquals(Collections.emptyList(), iterable);
assertFalse(cycle.hasNext());
}
public void testCycleOfTwo() {
Iterator<String> cycle = Iterators.cycle("a", "b");
for (int i = 0; i < 3; i++) {
assertTrue(cycle.hasNext());
assertEquals("a", cycle.next());
assertTrue(cycle.hasNext());
assertEquals("b", cycle.next());
}
}
public void testCycleOfTwoWithRemove() {
Iterable<String> iterable = Lists.newArrayList("a", "b");
Iterator<String> cycle = Iterators.cycle(iterable);
assertTrue(cycle.hasNext());
assertEquals("a", cycle.next());
assertTrue(cycle.hasNext());
assertEquals("b", cycle.next());
assertTrue(cycle.hasNext());
assertEquals("a", cycle.next());
cycle.remove();
assertEquals(Collections.singletonList("b"), iterable);
assertTrue(cycle.hasNext());
assertEquals("b", cycle.next());
assertTrue(cycle.hasNext());
assertEquals("b", cycle.next());
cycle.remove();
assertEquals(Collections.emptyList(), iterable);
assertFalse(cycle.hasNext());
}
public void testCycleRemoveWithoutNext() {
Iterator<String> cycle = Iterators.cycle("a", "b");
assertTrue(cycle.hasNext());
try {
cycle.remove();
fail("no exception thrown");
} catch (IllegalStateException expected) {
}
}
public void testCycleRemoveSameElementTwice() {
Iterator<String> cycle = Iterators.cycle("a", "b");
cycle.next();
cycle.remove();
try {
cycle.remove();
fail("no exception thrown");
} catch (IllegalStateException expected) {
}
}
public void testCycleWhenRemoveIsNotSupported() {
Iterable<String> iterable = asList("a", "b");
Iterator<String> cycle = Iterators.cycle(iterable);
cycle.next();
try {
cycle.remove();
fail("no exception thrown");
} catch (UnsupportedOperationException expected) {
}
}
public void testCycleRemoveAfterHasNext() {
Iterable<String> iterable = Lists.newArrayList("a");
Iterator<String> cycle = Iterators.cycle(iterable);
assertTrue(cycle.hasNext());
assertEquals("a", cycle.next());
assertTrue(cycle.hasNext());
cycle.remove();
assertEquals(Collections.emptyList(), iterable);
assertFalse(cycle.hasNext());
}
public void testCycleNoSuchElementException() {
Iterable<String> iterable = Lists.newArrayList("a");
Iterator<String> cycle = Iterators.cycle(iterable);
assertTrue(cycle.hasNext());
assertEquals("a", cycle.next());
cycle.remove();
assertFalse(cycle.hasNext());
try {
cycle.next();
fail();
} catch (NoSuchElementException expected) {}
}
public void testCycleUsingIteratorTester() throws Exception {
new IteratorTester<Integer>(5, UNMODIFIABLE, asList(1, 2, 1, 2, 1,
2, 1, 2, 1, 2, 1, 2), IteratorTester.KnownOrder.KNOWN_ORDER) {
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.cycle(asList(1, 2));
}
}.test();
}
public void testConcatNoIteratorsYieldsEmpty() throws Exception {
new EmptyIteratorTester() {
@SuppressWarnings("unchecked")
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.concat();
}
}.test();
}
public void testConcatOneEmptyIteratorYieldsEmpty() throws Exception {
new EmptyIteratorTester() {
@SuppressWarnings("unchecked")
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.concat(iterateOver());
}
}.test();
}
public void testConcatMultipleEmptyIteratorsYieldsEmpty() throws Exception {
new EmptyIteratorTester() {
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.concat(iterateOver(), iterateOver());
}
}.test();
}
public void testConcatSingletonYieldsSingleton() throws Exception {
new SingletonIteratorTester() {
@SuppressWarnings("unchecked")
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.concat(iterateOver(1));
}
}.test();
}
public void testConcatEmptyAndSingletonAndEmptyYieldsSingleton()
throws Exception {
new SingletonIteratorTester() {
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.concat(iterateOver(), iterateOver(1), iterateOver());
}
}.test();
}
public void testConcatSingletonAndSingletonYieldsDoubleton()
throws Exception {
new DoubletonIteratorTester() {
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.concat(iterateOver(1), iterateOver(2));
}
}.test();
}
public void testConcatSingletonAndSingletonWithEmptiesYieldsDoubleton()
throws Exception {
new DoubletonIteratorTester() {
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.concat(
iterateOver(1), iterateOver(), iterateOver(), iterateOver(2));
}
}.test();
}
public void testConcatUnmodifiable() throws Exception {
new IteratorTester<Integer>(5, UNMODIFIABLE, asList(1, 2),
IteratorTester.KnownOrder.KNOWN_ORDER) {
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.concat(asList(1).iterator(),
Arrays.<Integer>asList().iterator(), asList(2).iterator());
}
}.test();
}
/**
* Illustrates the somewhat bizarre behavior when a null is passed in.
*/
public void testConcatContainingNull() {
@SuppressWarnings("unchecked")
Iterator<Iterator<Integer>> input
= asList(iterateOver(1, 2), null, iterateOver(3)).iterator();
Iterator<Integer> result = Iterators.concat(input);
assertEquals(1, (int) result.next());
assertEquals(2, (int) result.next());
try {
result.hasNext();
fail("no exception thrown");
} catch (NullPointerException e) {
}
try {
result.next();
fail("no exception thrown");
} catch (NullPointerException e) {
}
// There is no way to get "through" to the 3. Buh-bye
}
@SuppressWarnings("unchecked")
public void testConcatVarArgsContainingNull() {
try {
Iterators.concat(iterateOver(1, 2), null, iterateOver(3), iterateOver(4),
iterateOver(5));
fail("no exception thrown");
} catch (NullPointerException e) {
}
}
public void testAddAllWithEmptyIterator() {
List<String> alreadyThere = Lists.newArrayList("already", "there");
boolean changed = Iterators.addAll(alreadyThere,
Iterators.<String>emptyIterator());
assertContentsInOrder(alreadyThere, "already", "there");
assertFalse(changed);
}
public void testAddAllToList() {
List<String> alreadyThere = Lists.newArrayList("already", "there");
List<String> freshlyAdded = Lists.newArrayList("freshly", "added");
boolean changed = Iterators.addAll(alreadyThere, freshlyAdded.iterator());
assertContentsInOrder(alreadyThere, "already", "there", "freshly", "added");
assertTrue(changed);
}
public void testAddAllToSet() {
Set<String> alreadyThere
= Sets.newLinkedHashSet(asList("already", "there"));
List<String> oneMore = Lists.newArrayList("there");
boolean changed = Iterators.addAll(alreadyThere, oneMore.iterator());
assertContentsInOrder(alreadyThere, "already", "there");
assertFalse(changed);
}
public void testNullPointerExceptions() throws Exception {
NullPointerTester tester = new NullPointerTester();
tester.testAllPublicStaticMethods(Iterators.class);
}
private static abstract class EmptyIteratorTester
extends IteratorTester<Integer> {
protected EmptyIteratorTester() {
super(3, MODIFIABLE, Collections.<Integer>emptySet(),
IteratorTester.KnownOrder.KNOWN_ORDER);
}
}
private static abstract class SingletonIteratorTester
extends IteratorTester<Integer> {
protected SingletonIteratorTester() {
super(3, MODIFIABLE, singleton(1), IteratorTester.KnownOrder.KNOWN_ORDER);
}
}
private static abstract class DoubletonIteratorTester
extends IteratorTester<Integer> {
protected DoubletonIteratorTester() {
super(5, MODIFIABLE, newArrayList(1, 2),
IteratorTester.KnownOrder.KNOWN_ORDER);
}
}
private static Iterator<Integer> iterateOver(final Integer... values) {
return newArrayList(values).iterator();
}
public void testElementsEqual() {
Iterable<?> a;
Iterable<?> b;
// Base case.
a = Lists.newArrayList();
b = Collections.emptySet();
assertTrue(Iterators.elementsEqual(a.iterator(), b.iterator()));
// A few elements.
a = asList(4, 8, 15, 16, 23, 42);
b = asList(4, 8, 15, 16, 23, 42);
assertTrue(Iterators.elementsEqual(a.iterator(), b.iterator()));
// The same, but with nulls.
a = asList(4, 8, null, 16, 23, 42);
b = asList(4, 8, null, 16, 23, 42);
assertTrue(Iterators.elementsEqual(a.iterator(), b.iterator()));
// Different Iterable types (still equal elements, though).
a = ImmutableList.of(4, 8, 15, 16, 23, 42);
b = asList(4, 8, 15, 16, 23, 42);
assertTrue(Iterators.elementsEqual(a.iterator(), b.iterator()));
// An element differs.
a = asList(4, 8, 15, 12, 23, 42);
b = asList(4, 8, 15, 16, 23, 42);
assertFalse(Iterators.elementsEqual(a.iterator(), b.iterator()));
// null versus non-null.
a = asList(4, 8, 15, null, 23, 42);
b = asList(4, 8, 15, 16, 23, 42);
assertFalse(Iterators.elementsEqual(a.iterator(), b.iterator()));
assertFalse(Iterators.elementsEqual(b.iterator(), a.iterator()));
// Different lengths.
a = asList(4, 8, 15, 16, 23);
b = asList(4, 8, 15, 16, 23, 42);
assertFalse(Iterators.elementsEqual(a.iterator(), b.iterator()));
assertFalse(Iterators.elementsEqual(b.iterator(), a.iterator()));
// Different lengths, one is empty.
a = Collections.emptySet();
b = asList(4, 8, 15, 16, 23, 42);
assertFalse(Iterators.elementsEqual(a.iterator(), b.iterator()));
assertFalse(Iterators.elementsEqual(b.iterator(), a.iterator()));
}
public void testPartition_badSize() {
Iterator<Integer> source = Iterators.singletonIterator(1);
try {
Iterators.partition(source, 0);
fail();
} catch (IllegalArgumentException expected) {
}
}
public void testPartition_empty() {
Iterator<Integer> source = Iterators.emptyIterator();
Iterator<List<Integer>> partitions = Iterators.partition(source, 1);
assertFalse(partitions.hasNext());
}
public void testPartition_singleton1() {
Iterator<Integer> source = Iterators.singletonIterator(1);
Iterator<List<Integer>> partitions = Iterators.partition(source, 1);
assertTrue(partitions.hasNext());
assertTrue(partitions.hasNext());
assertEquals(ImmutableList.of(1), partitions.next());
assertFalse(partitions.hasNext());
}
public void testPartition_singleton2() {
Iterator<Integer> source = Iterators.singletonIterator(1);
Iterator<List<Integer>> partitions = Iterators.partition(source, 2);
assertTrue(partitions.hasNext());
assertTrue(partitions.hasNext());
assertEquals(ImmutableList.of(1), partitions.next());
assertFalse(partitions.hasNext());
}
public void testPartition_general() throws Exception {
new IteratorTester<List<Integer>>(5,
IteratorFeature.UNMODIFIABLE,
ImmutableList.of(
asList(1, 2, 3),
asList(4, 5, 6),
asList(7)),
IteratorTester.KnownOrder.KNOWN_ORDER) {
@Override protected Iterator<List<Integer>> newTargetIterator() {
Iterator<Integer> source = Iterators.forArray(1, 2, 3, 4, 5, 6, 7);
return Iterators.partition(source, 3);
}
}.test();
}
public void testPartition_view() {
List<Integer> list = asList(1, 2);
Iterator<List<Integer>> partitions
= Iterators.partition(list.iterator(), 1);
// Changes before the partition is retrieved are reflected
list.set(0, 3);
List<Integer> first = partitions.next();
// Changes after are not
list.set(0, 4);
assertEquals(ImmutableList.of(3), first);
}
public void testPartitionRandomAccess() {
Iterator<Integer> source = asList(1, 2, 3).iterator();
Iterator<List<Integer>> partitions = Iterators.partition(source, 2);
assertTrue(partitions.next() instanceof RandomAccess);
assertTrue(partitions.next() instanceof RandomAccess);
}
public void testPaddedPartition_badSize() {
Iterator<Integer> source = Iterators.singletonIterator(1);
try {
Iterators.paddedPartition(source, 0);
fail();
} catch (IllegalArgumentException expected) {
}
}
public void testPaddedPartition_empty() {
Iterator<Integer> source = Iterators.emptyIterator();
Iterator<List<Integer>> partitions = Iterators.paddedPartition(source, 1);
assertFalse(partitions.hasNext());
}
public void testPaddedPartition_singleton1() {
Iterator<Integer> source = Iterators.singletonIterator(1);
Iterator<List<Integer>> partitions = Iterators.paddedPartition(source, 1);
assertTrue(partitions.hasNext());
assertTrue(partitions.hasNext());
assertEquals(ImmutableList.of(1), partitions.next());
assertFalse(partitions.hasNext());
}
public void testPaddedPartition_singleton2() {
Iterator<Integer> source = Iterators.singletonIterator(1);
Iterator<List<Integer>> partitions = Iterators.paddedPartition(source, 2);
assertTrue(partitions.hasNext());
assertTrue(partitions.hasNext());
assertEquals(asList(1, null), partitions.next());
assertFalse(partitions.hasNext());
}
public void testPaddedPartition_general() throws Exception {
new IteratorTester<List<Integer>>(5,
IteratorFeature.UNMODIFIABLE,
ImmutableList.of(
asList(1, 2, 3),
asList(4, 5, 6),
asList(7, null, null)),
IteratorTester.KnownOrder.KNOWN_ORDER) {
@Override protected Iterator<List<Integer>> newTargetIterator() {
Iterator<Integer> source = Iterators.forArray(1, 2, 3, 4, 5, 6, 7);
return Iterators.paddedPartition(source, 3);
}
}.test();
}
public void testPaddedPartition_view() {
List<Integer> list = asList(1, 2);
Iterator<List<Integer>> partitions
= Iterators.paddedPartition(list.iterator(), 1);
// Changes before the PaddedPartition is retrieved are reflected
list.set(0, 3);
List<Integer> first = partitions.next();
// Changes after are not
list.set(0, 4);
assertEquals(ImmutableList.of(3), first);
}
public void testPaddedPartitionRandomAccess() {
Iterator<Integer> source = asList(1, 2, 3).iterator();
Iterator<List<Integer>> partitions = Iterators.paddedPartition(source, 2);
assertTrue(partitions.next() instanceof RandomAccess);
assertTrue(partitions.next() instanceof RandomAccess);
}
public void testForArrayEmpty() {
String[] array = new String[0];
Iterator<String> iterator = Iterators.forArray(array);
assertFalse(iterator.hasNext());
try {
iterator.next();
fail();
} catch (NoSuchElementException expected) {}
}
public void testForArrayTypical() {
String[] array = {"foo", "bar"};
Iterator<String> iterator = Iterators.forArray(array);
assertTrue(iterator.hasNext());
assertEquals("foo", iterator.next());
assertTrue(iterator.hasNext());
try {
iterator.remove();
fail();
} catch (UnsupportedOperationException expected) {}
assertEquals("bar", iterator.next());
assertFalse(iterator.hasNext());
try {
iterator.next();
fail();
} catch (NoSuchElementException expected) {}
}
public void testForArrayOffset() {
String[] array = {"foo", "bar", "cat", "dog"};
Iterator<String> iterator = Iterators.forArray(array, 1, 2);
assertTrue(iterator.hasNext());
assertEquals("bar", iterator.next());
assertTrue(iterator.hasNext());
assertEquals("cat", iterator.next());
assertFalse(iterator.hasNext());
try {
Iterators.forArray(array, 2, 3);
fail();
} catch (IndexOutOfBoundsException expected) {}
}
public void testForArrayLength0() {
String[] array = {"foo", "bar"};
assertFalse(Iterators.forArray(array, 0, 0).hasNext());
assertFalse(Iterators.forArray(array, 1, 0).hasNext());
assertFalse(Iterators.forArray(array, 2, 0).hasNext());
try {
Iterators.forArray(array, -1, 0);
fail();
} catch (IndexOutOfBoundsException expected) {}
try {
Iterators.forArray(array, 3, 0);
fail();
} catch (IndexOutOfBoundsException expected) {}
}
public void testForArrayUsingTester() throws Exception {
new IteratorTester<Integer>(6, UNMODIFIABLE, asList(1, 2, 3),
IteratorTester.KnownOrder.KNOWN_ORDER) {
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.forArray(1, 2, 3);
}
}.test();
}
public void testForArrayWithOffsetUsingTester() throws Exception {
new IteratorTester<Integer>(6, UNMODIFIABLE, asList(1, 2, 3),
IteratorTester.KnownOrder.KNOWN_ORDER) {
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.forArray(new Integer[] { 0, 1, 2, 3, 4 }, 1, 3);
}
}.test();
}
public void testForEnumerationEmpty() {
Enumeration<Integer> enumer = enumerate();
Iterator<Integer> iter = Iterators.forEnumeration(enumer);
assertFalse(iter.hasNext());
try {
iter.next();
fail();
} catch (NoSuchElementException expected) {
}
}
public void testForEnumerationSingleton() {
Enumeration<Integer> enumer = enumerate(1);
Iterator<Integer> iter = Iterators.forEnumeration(enumer);
assertTrue(iter.hasNext());
assertTrue(iter.hasNext());
assertEquals(1, (int) iter.next());
try {
iter.remove();
fail();
} catch (UnsupportedOperationException expected) {
}
assertFalse(iter.hasNext());
try {
iter.next();
fail();
} catch (NoSuchElementException expected) {
}
}
public void testForEnumerationTypical() {
Enumeration<Integer> enumer = enumerate(1, 2, 3);
Iterator<Integer> iter = Iterators.forEnumeration(enumer);
assertTrue(iter.hasNext());
assertEquals(1, (int) iter.next());
assertTrue(iter.hasNext());
assertEquals(2, (int) iter.next());
assertTrue(iter.hasNext());
assertEquals(3, (int) iter.next());
assertFalse(iter.hasNext());
}
public void testAsEnumerationEmpty() {
Iterator<Integer> iter = Iterators.emptyIterator();
Enumeration<Integer> enumer = Iterators.asEnumeration(iter);
assertFalse(enumer.hasMoreElements());
try {
enumer.nextElement();
fail();
} catch (NoSuchElementException expected) {
}
}
public void testAsEnumerationSingleton() {
Iterator<Integer> iter = ImmutableList.of(1).iterator();
Enumeration<Integer> enumer = Iterators.asEnumeration(iter);
assertTrue(enumer.hasMoreElements());
assertTrue(enumer.hasMoreElements());
assertEquals(1, (int) enumer.nextElement());
assertFalse(enumer.hasMoreElements());
try {
enumer.nextElement();
fail();
} catch (NoSuchElementException expected) {
}
}
public void testAsEnumerationTypical() {
Iterator<Integer> iter = ImmutableList.of(1, 2, 3).iterator();
Enumeration<Integer> enumer = Iterators.asEnumeration(iter);
assertTrue(enumer.hasMoreElements());
assertEquals(1, (int) enumer.nextElement());
assertTrue(enumer.hasMoreElements());
assertEquals(2, (int) enumer.nextElement());
assertTrue(enumer.hasMoreElements());
assertEquals(3, (int) enumer.nextElement());
assertFalse(enumer.hasMoreElements());
}
private static Enumeration<Integer> enumerate(Integer... ints) {
Vector<Integer> vector = new Vector<Integer>();
vector.addAll(asList(ints));
return vector.elements();
}
public void testToString() {
List<String> list = Collections.emptyList();
assertEquals("[]", Iterators.toString(list.iterator()));
list = Lists.newArrayList("yam", "bam", "jam", "ham");
assertEquals("[yam, bam, jam, ham]", Iterators.toString(list.iterator()));
}
public void testGetLast_basic() {
List<String> list = newArrayList();
list.add("a");
list.add("b");
assertEquals("b", getLast(list.iterator()));
}
public void testGetLast_exception() {
List<String> list = newArrayList();
try {
getLast(list.iterator());
fail();
} catch (NoSuchElementException expected) {
}
}
public void testGet_basic() {
List<String> list = newArrayList();
list.add("a");
list.add("b");
Iterator<String> iterator = list.iterator();
assertEquals("b", get(iterator, 1));
assertFalse(iterator.hasNext());
}
public void testGet_atSize() {
List<String> list = newArrayList();
list.add("a");
list.add("b");
Iterator<String> iterator = list.iterator();
try {
get(iterator, 2);
fail();
} catch (IndexOutOfBoundsException expected) {}
assertFalse(iterator.hasNext());
}
public void testGet_pastEnd() {
List<String> list = newArrayList();
list.add("a");
list.add("b");
Iterator<String> iterator = list.iterator();
try {
get(iterator, 5);
fail();
} catch (IndexOutOfBoundsException expected) {}
assertFalse(iterator.hasNext());
}
public void testGet_empty() {
List<String> list = newArrayList();
Iterator<String> iterator = list.iterator();
try {
get(iterator, 0);
fail();
} catch (IndexOutOfBoundsException expected) {}
assertFalse(iterator.hasNext());
}
public void testGet_negativeIndex() {
List<String> list = newArrayList("a", "b", "c");
Iterator<String> iterator = list.iterator();
try {
get(iterator, -1);
fail();
} catch (IndexOutOfBoundsException expected) {}
}
public void testFrequency() {
List<String> list = newArrayList("a", null, "b", null, "a", null);
assertEquals(2, Iterators.frequency(list.iterator(), "a"));
assertEquals(1, Iterators.frequency(list.iterator(), "b"));
assertEquals(0, Iterators.frequency(list.iterator(), "c"));
assertEquals(0, Iterators.frequency(list.iterator(), 4.2));
assertEquals(3, Iterators.frequency(list.iterator(), null));
}
public void testSingletonIterator() throws Exception {
new IteratorTester<Integer>(
3, UNMODIFIABLE, singleton(1), IteratorTester.KnownOrder.KNOWN_ORDER) {
@Override protected Iterator<Integer> newTargetIterator() {
return Iterators.singletonIterator(1);
}
}.test();
}
public void testRemoveAll() {
List<String> list = newArrayList("a", "b", "c", "d", "e");
assertTrue(Iterators.removeAll(
list.iterator(), newArrayList("b", "d", "f")));
assertEquals(newArrayList("a", "c", "e"), list);
assertFalse(Iterators.removeAll(
list.iterator(), newArrayList("x", "y", "z")));
assertEquals(newArrayList("a", "c", "e"), list);
}
public void testRemoveIf() {
List<String> list = newArrayList("a", "b", "c", "d", "e");
assertTrue(Iterators.removeIf(
list.iterator(),
new Predicate<String>() {
public boolean apply(String s) {
return s.equals("b") || s.equals("d") || s.equals("f");
}
}));
assertEquals(newArrayList("a", "c", "e"), list);
assertFalse(Iterators.removeIf(
list.iterator(),
new Predicate<String>() {
public boolean apply(String s) {
return s.equals("x") || s.equals("y") || s.equals("z");
}
}));
assertEquals(newArrayList("a", "c", "e"), list);
}
public void testRetainAll() {
List<String> list = newArrayList("a", "b", "c", "d", "e");
assertTrue(Iterators.retainAll(
list.iterator(), newArrayList("b", "d", "f")));
assertEquals(newArrayList("b", "d"), list);
assertFalse(Iterators.retainAll(
list.iterator(), newArrayList("b", "e", "d")));
assertEquals(newArrayList("b", "d"), list);
}
private static Test testsForRemoveAllAndRetainAll() {
return ListTestSuiteBuilder.using(new TestStringListGenerator() {
@Override public List<String> create(final String[] elements) {
final List<String> delegate = newArrayList(elements);
return new ForwardingList<String>() {
@Override protected List<String> delegate() {
return delegate;
}
@Override public boolean removeAll(Collection<?> c) {
return Iterators.removeAll(iterator(), c);
}
@Override public boolean retainAll(Collection<?> c) {
return Iterators.retainAll(iterator(), c);
}
};
}
})
.named("ArrayList with Iterators.removeAll and retainAll")
.withFeatures(
ListFeature.GENERAL_PURPOSE,
CollectionFeature.ALLOWS_NULL_VALUES,
CollectionSize.ANY)
.createTestSuite();
}
public void testRecursiveCallsToPeekingIteratorShouldAvoidRewrapping() {
Iterator<Integer> iterator = newArrayList(1, 2, 3).iterator();
// Should be able to make a PeekingIterator<T> from an Iterator<? extends T>
PeekingIterator<Number> first = Iterators.<Number>peekingIterator(iterator);
PeekingIterator<Number> second = Iterators.peekingIterator(first);
assertSame("Should not rewrap iterator returned by peekingIterator()",
first, second);
}
}