jdk-24/test/jdk/java/util/stream/GatherersWindowFixedTest.java
Viktor Klang ef0dc2518e 8342707: Prepare Gatherers for graduation from Preview
Reviewed-by: alanb, liach
2024-11-11 19:57:26 +00:00

134 lines
4.8 KiB
Java

/*
* Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
import java.util.Arrays;
import java.util.List;
import java.util.stream.Gatherers;
import java.util.stream.Stream;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.MethodSource;
import org.junit.jupiter.params.provider.ValueSource;
import static org.junit.jupiter.api.Assertions.*;
import static org.junit.jupiter.api.Assumptions.*;
/**
* @test
* @summary Tests the API and contract of Gatherers.windowFixed
* @run junit GatherersWindowFixedTest
*/
public class GatherersWindowFixedTest {
record Config(int streamSize, boolean parallel) {
Stream<Integer> stream() {
var stream = Stream.iterate(1, i -> i + 1).limit(streamSize);
stream = parallel ? stream.parallel() : stream.sequential();
return stream;
}
}
static final Stream<Integer> sizes(){
return Stream.of(0,1,10,33,99,9999);
}
static final Stream<Config> sequentialAndParallel(int size) {
return Stream.of(false, true)
.map(parallel ->
new Config(size, parallel));
}
static final Stream<Config> configurations() {
return sizes().flatMap(i -> sequentialAndParallel(i));
}
static final Stream<Config> nonempty_configurations() {
return sizes().filter(i -> i > 0).flatMap(i -> sequentialAndParallel(i));
}
@ParameterizedTest
@ValueSource(ints = { Integer.MIN_VALUE, -999, -1, 0})
public void throwsIAEWhenWindowSizeIsSmallerThanOne(int windowSize) {
assertThrows(IllegalArgumentException.class,
() -> Gatherers.windowFixed(windowSize));
}
@ParameterizedTest
@MethodSource("nonempty_configurations")
public void behavesAsExpectedWhenWindowSizeIsSizeOfStream(Config config) {
final var streamSize = config.streamSize();
final var result = config.stream()
.gather(Gatherers.windowFixed(streamSize))
.toList();
assertEquals(1, result.size());
assertEquals(config.stream().toList(), result.get(0));
}
@Test
public void toleratesNullElements() {
assertEquals(
List.of(Arrays.asList(null, null)),
Stream.of(null, null)
.gather(Gatherers.windowFixed(2))
.toList());
}
@Test
public void throwsUOEWhenWindowsAreAttemptedToBeModified() {
var window = Stream.of(1)
.gather(Gatherers.windowFixed(1))
.findFirst()
.get();
assertThrows(UnsupportedOperationException.class,
() -> window.add(2));
}
@ParameterizedTest
@MethodSource("configurations")
public void behavesAsExpected(Config config) {
final var streamSize = config.streamSize();
// Tests that the layout of the returned data is as expected
for (var windowSize : List.of(1, 2, 3, 10)) {
final var expectLastWindowSize = streamSize % windowSize == 0 ? windowSize : streamSize % windowSize;
final var expectedSize = (streamSize / windowSize) + ((streamSize % windowSize == 0) ? 0 : 1);
final var expected = config.stream().toList().iterator();
final var result = config.stream()
.gather(Gatherers.windowFixed(windowSize))
.toList();
int currentWindow = 0;
for (var window : result) {
++currentWindow;
assertEquals(currentWindow < expectedSize ? windowSize : expectLastWindowSize, window.size());
for (var element : window)
assertEquals(expected.next(), element);
}
assertEquals(expectedSize, currentWindow);
}
}
}