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 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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 * 2 along with this work; if not, write to the Free Software Foundation,

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/**

 * @test

 * @run testng UnmodifiableMapEntrySet

 * @summary Unit tests for wrapping classes should delegate to default methods

 */

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.Spliterator;

import java.util.TreeMap;

import java.util.function.Consumer;

import java.util.function.Function;

import java.util.function.Supplier;

import org.testng.annotations.Test;

import org.testng.annotations.DataProvider;

import static org.testng.Assert.assertEquals;

@Test(groups = "unit")

public class UnmodifiableMapEntrySet {

    static Object[][] collections;

    static <M extends Map<Integer, Integer>> M fillMap(int size, M m) {

        for (int i = 0; i < size; i++) {

            m.put(i, i);

        }

        return m;

    }

    @DataProvider(name="maps")

    static Object[][] mapCases() {

        if (collections != null) {

            return collections;

        }

        List<Object[]> cases = new ArrayList<>();

        for (int size : new int[] {1, 2, 16}) {

            cases.add(new Object[] {

                    String.format("new HashMap(%d)", size),

                    (Supplier<Map<Integer, Integer>>)

                    () -> Collections.unmodifiableMap(fillMap(size, new HashMap<>())) });

            cases.add(new Object[] {

                    String.format("new TreeMap(%d)", size),

                    (Supplier<Map<Integer, Integer>>)

                    () -> Collections.unmodifiableSortedMap(fillMap(size, new TreeMap<>())) });

        }

        return cases.toArray(new Object[0][]);

    }

    static class EntryConsumer implements Consumer<Map.Entry<Integer, Integer>> {

        int updates;

        @Override

        public void accept(Map.Entry<Integer, Integer> me) {

            try {

                me.setValue(Integer.MAX_VALUE);

                updates++;

            } catch (UnsupportedOperationException e) {

            }

        }

        void assertNoUpdates() {

            assertEquals(updates, 0, "Updates to entries");

        }

    }

    void testWithEntryConsumer(Consumer<EntryConsumer> c) {

        EntryConsumer ec = new EntryConsumer();

        c.accept(ec);

        ec.assertNoUpdates();

    }

    @Test(dataProvider = "maps")

    public void testForEach(String d, Supplier<Map<Integer, Integer>> ms) {

        testWithEntryConsumer(

                ec -> ms.get().entrySet().forEach(ec));

    }

    @Test(dataProvider = "maps")

    public void testIteratorForEachRemaining(String d, Supplier<Map<Integer, Integer>> ms) {

        testWithEntryConsumer(

                ec -> ms.get().entrySet().iterator().forEachRemaining(ec));

    }

    @Test(dataProvider = "maps")

    public void testIteratorNext(String d, Supplier<Map<Integer, Integer>> ms) {

        testWithEntryConsumer(ec -> {

            for (Map.Entry<Integer, Integer> me : ms.get().entrySet()) {

                ec.accept(me);

            }

        });

    }

    @Test(dataProvider = "maps")

    public void testSpliteratorForEachRemaining(String d, Supplier<Map<Integer, Integer>> ms) {

        testSpliterator(

                ms.get().entrySet()::spliterator,

                // Higher order function returning a consumer that

                // traverses all spliterator elements using an EntryConsumer

                s -> ec -> s.forEachRemaining(ec));

    }

    @Test(dataProvider = "maps")

    public void testSpliteratorTryAdvance(String d, Supplier<Map<Integer, Integer>> ms) {

        testSpliterator(

                ms.get().entrySet()::spliterator,

                // Higher order function returning a consumer that

                // traverses all spliterator elements using an EntryConsumer

                s -> ec -> { while (s.tryAdvance(ec)); });

    }

    void testSpliterator(Supplier<Spliterator<Map.Entry<Integer, Integer>>> ss,

                         // Higher order function that given a spliterator returns a

                         // consumer for that spliterator which traverses elements

                         // using an EntryConsumer

                         Function<Spliterator<Map.Entry<Integer, Integer>>, Consumer<EntryConsumer>> sc) {

        testWithEntryConsumer(sc.apply(ss.get()));

        Spliterator<Map.Entry<Integer, Integer>> s = ss.get();

        Spliterator<Map.Entry<Integer, Integer>> split = s.trySplit();

        if (split != null) {

            testWithEntryConsumer(sc.apply(split));

            testWithEntryConsumer(sc.apply(s));

        }

    }

    @Test(dataProvider = "maps")

    public void testStreamForEach(String d, Supplier<Map<Integer, Integer>> ms) {

        testWithEntryConsumer(ec -> ms.get().entrySet().stream().forEach(ec));

    }

    @Test(dataProvider = "maps")

    public void testParallelStreamForEach(String d, Supplier<Map<Integer, Integer>> ms) {

        testWithEntryConsumer(ec -> ms.get().entrySet().parallelStream().forEach(ec));

    }

}