DistinctSpliteratorTest.java

/*
 * Copyright 2015, 2016 Tagir Valeev
 * 
 * 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 one.util.streamex;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import java.util.Spliterator;
import java.util.stream.IntStream;

import one.util.streamex.DistinctSpliterator;

import org.junit.Test;

import static one.util.streamex.TestHelpers.*;
import static org.junit.Assert.*;

/**
 * @author Tagir Valeev
 */
public class DistinctSpliteratorTest {

    @Test
    public void testSpliterator() {
        checkSpliterator("Distinct2", Arrays.asList("b"), () -> new DistinctSpliterator<>(Arrays.asList("a", null, "b",
            "c", "b", null, "c", "b").spliterator(), 3));
        checkSpliterator("Distinct34", Arrays.asList(0), () -> new DistinctSpliterator<>(IntStream.range(0, 100).map(
            x -> x % 3).boxed().spliterator(), 34));

        assertEquals(Spliterator.DISTINCT | Spliterator.ORDERED, new DistinctSpliterator<>(Arrays.asList("a", null,
            "b", "c", "b", null, "c", "b").spliterator(), 3).characteristics());
        assertEquals(Spliterator.DISTINCT | Spliterator.ORDERED | Spliterator.IMMUTABLE | Spliterator.SORTED
            | Spliterator.NONNULL, new DistinctSpliterator<>(IntStream.range(0, 100).spliterator(), 3)
                .characteristics());
        assertEquals(100, new DistinctSpliterator<>(IntStream.range(0, 100).spliterator(), 3).estimateSize());
    }
    
    @Test
    public void testAdvanceSplit() {
        DistinctSpliterator<String> ds = new DistinctSpliterator<>(Arrays.asList("a", null, "b", "c", "b", null, "c",
            "b").spliterator(), 2);
        Set<String> result = new HashSet<>();
        assertTrue(ds.tryAdvance(result::add));
        assertTrue(ds.tryAdvance(result::add));
        Spliterator<String> prefix = ds.trySplit();
        prefix.forEachRemaining(result::add);
        ds.forEachRemaining(result::add);
        assertEquals(StreamEx.of(null, "b", "c").toSet(), result);
    }
}