FilterTest.java

package com.annimon.stream.streamtests;

import com.annimon.stream.Functions;
import com.annimon.stream.Stream;
import com.annimon.stream.function.Predicate;
import java.util.NoSuchElementException;
import org.junit.Test;
import static com.annimon.stream.test.hamcrest.StreamMatcher.assertElements;
import static org.hamcrest.Matchers.contains;

public final class FilterTest {

    @Test
    public void testFilter() {
        Stream.range(0, 10)
                .filter(Functions.remainder(2))
                .custom(assertElements(contains(
                      0, 2, 4, 6, 8
                )));
    }
    
    @Test(expected = NoSuchElementException.class)
    public void testFilterIteratorNextOnEmpty() {
        Stream.<Integer>empty()
                .filter(Functions.remainder(2))
                .iterator()
                .next();
    }
    
    @Test(expected = UnsupportedOperationException.class)
    public void testFilterIteratorRemove() {
        Stream.range(0, 10)
                .filter(Functions.remainder(2))
                .iterator()
                .remove();
    }
    
    @Test
    public void testFilterWithOrPredicate() {
        Predicate<Integer> predicate = Predicate.Util.or(Functions.remainder(2), Functions.remainder(3));
        Stream.range(0, 10)
                .filter(predicate)
                .custom(assertElements(contains(
                      0, 2, 3, 4, 6, 8, 9
                )));
    }

    @Test
    public void testFilterWithAndPredicate() {
        Predicate<Integer> predicate = Predicate.Util.and(Functions.remainder(2), Functions.remainder(3));
        Stream.range(0, 10)
                .filter(predicate)
                .custom(assertElements(contains(
                      0, 6
                )));
    }

    @Test
    public void testFilterWithXorPredicate() {
        Predicate<Integer> predicate = Predicate.Util.xor(Functions.remainder(2), Functions.remainder(3));
        Stream.range(0, 10)
                .filter(predicate)
                .custom(assertElements(contains(
                      2, 3, 4, 8, 9
                )));
    }
}