ThenComposeExceptionTest.java revision 12677:a4299d47bd00 
1/*
2 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24import org.testng.Assert;
25import org.testng.annotations.DataProvider;
26import org.testng.annotations.Test;
27
28import java.util.ArrayList;
29import java.util.List;
30import java.util.concurrent.CompletableFuture;
31import java.util.concurrent.CompletionException;
32import java.util.concurrent.atomic.AtomicReference;
33import java.util.function.BiFunction;
34import java.util.function.Consumer;
35
36
37/**
38 * @test
39 * @bug 8068432 8072030
40 * @run testng ThenComposeExceptionTest
41 * @summary Test that CompletableFuture.thenCompose works correctly if the
42 * composing future completes exceptionally
43 */
44@Test
45public class ThenComposeExceptionTest {
46
47    static final BiFunction<CompletableFuture<String>, CompletableFuture<String>, CompletableFuture<String>>
48            THEN_COMPOSE = (f, fe) -> f.thenCompose(s -> fe);
49
50    static final BiFunction<CompletableFuture<String>, CompletableFuture<String>, CompletableFuture<String>>
51            THEN_COMPOSE_ASYNC = (f, fe) -> f.thenComposeAsync(s -> fe);
52
53    static final Consumer<CompletableFuture<String>>
54            COMPLETE_EXCEPTIONALLY = f -> f.completeExceptionally(new RuntimeException());
55
56    static final Consumer<CompletableFuture<String>>
57            NOP = f -> { };
58
59    static Object[][] actionsDataProvider;
60
61    @DataProvider(name = "actions")
62    static Object[][] actionsDataProvider() {
63        if (actionsDataProvider != null) {
64            return actionsDataProvider;
65        }
66
67        List<Object[]> data = new ArrayList<>();
68        data.add(new Object[]{"thenCompose and completeExceptionally", NOP, THEN_COMPOSE, COMPLETE_EXCEPTIONALLY});
69        data.add(new Object[]{"thenComposeAsync and completeExceptionally", NOP, THEN_COMPOSE_ASYNC, COMPLETE_EXCEPTIONALLY});
70        data.add(new Object[]{"completeExceptionally and thenCompose", COMPLETE_EXCEPTIONALLY, THEN_COMPOSE, NOP});
71        data.add(new Object[]{"completeExceptionally and thenComposeAsync", COMPLETE_EXCEPTIONALLY, THEN_COMPOSE_ASYNC, NOP});
72
73        return actionsDataProvider = data.toArray(new Object[0][]);
74    }
75
76    @Test(dataProvider = "actions")
77    public void testThenCompose(
78            String description,
79            Consumer<CompletableFuture<String>> beforeAction,
80            BiFunction<CompletableFuture<String>, CompletableFuture<String>, CompletableFuture<String>> composeFunction,
81            Consumer<CompletableFuture<String>> afterAction) throws Exception {
82        CompletableFuture<String> f = new CompletableFuture<>();
83        CompletableFuture<String> fe = new CompletableFuture<>();
84
85        // Ensure pre-composed stage is completed to trigger
86        // processing the composing future
87        f.complete("");
88
89        beforeAction.accept(fe);
90
91        CompletableFuture<String> f_thenCompose = composeFunction.apply(f, fe);
92        Assert.assertNotSame(f_thenCompose, fe, "Composed CompletableFuture returned directly");
93
94        AtomicReference<Throwable> eOnWhenComplete = new AtomicReference<>();
95        CompletableFuture<String> f_whenComplete = f_thenCompose.
96                whenComplete((r, e) -> eOnWhenComplete.set(e));
97
98        afterAction.accept(fe);
99
100        Throwable eOnJoined = null;
101        try {
102            f_thenCompose.join();
103        }
104        catch (Throwable t) {
105            eOnJoined = t;
106        }
107        Assert.assertTrue(eOnJoined instanceof CompletionException,
108                          "Incorrect exception reported when joined on thenCompose: " + eOnJoined);
109
110        // Need to wait for f_whenComplete to complete to avoid
111        // race condition when updating eOnWhenComplete
112        eOnJoined = null;
113        try {
114            f_whenComplete.join();
115        } catch (Throwable t) {
116            eOnJoined = t;
117        }
118        Assert.assertTrue(eOnJoined instanceof CompletionException,
119                          "Incorrect exception reported when joined on whenComplete: " + eOnJoined);
120        Assert.assertTrue(eOnWhenComplete.get() instanceof CompletionException,
121                          "Incorrect exception passed to whenComplete: " + eOnWhenComplete.get());
122    }
123}
124