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package org.ruoxue.java_147.stream;

import static org.junit.Assert.*;

import java.util.Arrays;
import java.util.List;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

import org.junit.Test;

public class StreamInitializationTest {

	@Test
	public void empty() {
		int expectedCount = 0;
		Stream<String> stream = Stream.empty();
		System.out.println(stream);
		long count = stream.peek(System.out::println).count();
		assertEquals(expectedCount, count);

		Stream<Integer> intStream = Stream.empty();
		System.out.println(intStream);
		count = intStream.peek(System.out::println).count();
		assertEquals(expectedCount, count);
	}

	@Test
	public void iterate() {
		int expectedCount = 3;
		Stream<String> stream = Stream.iterate("Coconut", n -> n + 1).limit(3);
		System.out.println(stream);
		long count = stream.peek(System.out::println).count();
		assertEquals(expectedCount, count);

		Stream<Integer> intStream = Stream.iterate(2, n -> n * n).limit(3);
		System.out.println(intStream);
		count = intStream.peek(System.out::println).count();
		assertEquals(expectedCount, count);
	}

	@Test
	public void iterator() {
		int expectedCount = 3;
		List<String> list = Arrays.asList("Coconut", "Lichee", "Plum");
		Spliterator<String> spliterator = Spliterators.spliteratorUnknownSize(list.iterator(), Spliterator.NONNULL);
		Stream<String> stream = StreamSupport.stream(spliterator, false);
		System.out.println(stream);
		long count = stream.peek(System.out::println).count();
		assertEquals(expectedCount, count);

		List<Integer> intList = Arrays.asList(1, 2, 3);
		Spliterator<Integer> intSpliterator = Spliterators.spliteratorUnknownSize(intList.iterator(),
				Spliterator.NONNULL);
		Stream<Integer> intStream = StreamSupport.stream(intSpliterator, false);
		System.out.println(intStream);
		count = intStream.peek(System.out::println).count();
		assertEquals(expectedCount, count);
	}

	@Test
	public void iterable() {
		int expectedCount = 3;
		Iterable<String> iterable = Arrays.asList("Coconut", "Lichee", "Plum");
		Stream<String> stream = StreamSupport.stream(iterable.spliterator(), false);
		System.out.println(stream);
		long count = stream.peek(System.out::println).count();
		assertEquals(expectedCount, count);

		Iterable<Integer> intIterable = Arrays.asList(1, 2, 3);
		Stream<Integer> intStream = StreamSupport.stream(intIterable.spliterator(), false);
		System.out.println(intStream);
		count = intStream.peek(System.out::println).count();
		assertEquals(expectedCount, count);
	}

	@Test
	public void intStream() {
		int expectedCount = 3;
		IntStream intStream = IntStream.of(10, 20, 30);
		long count = intStream.peek(System.out::println).count();
		assertEquals(expectedCount, count);
	}

	@Test
	public void longStream() {
		int expectedCount = 3;
		LongStream stream = LongStream.of(40, 50, 60);
		long count = stream.peek(System.out::println).count();
		assertEquals(expectedCount, count);
	}

	@Test
	public void doubleStream() {
		int expectedCount = 3;
		DoubleStream stream = DoubleStream.of(70.0, 80.0, 90.0);
		long count = stream.peek(System.out::println).count();
		assertEquals(expectedCount, count);
	}
}