1/*
2 * Copyright 2015-present Facebook, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <folly/futures/Future.h>
18#include <folly/portability/GTest.h>
19
20#include <thread>
21
22using namespace folly;
23
24namespace {
25struct Widget {
26 int v_, copied_, moved_;
27 /* implicit */ Widget(int v) : v_(v), copied_(0), moved_(0) {}
28 Widget(const Widget& other)
29 : v_(other.v_), copied_(other.copied_ + 1), moved_(other.moved_) {}
30 Widget(Widget&& other) noexcept
31 : v_(other.v_), copied_(other.copied_), moved_(other.moved_ + 1) {}
32 Widget& operator=(const Widget& /* other */) {
33 throw std::logic_error("unexpected copy assignment");
34 }
35 Widget& operator=(Widget&& /* other */) {
36 throw std::logic_error("unexpected move assignment");
37 }
38};
39
40struct CountedWidget : Widget {
41 static std::vector<Widget*> instances_;
42 bool alive = true;
43 /* implicit */ CountedWidget(int v) : Widget(v) {
44 instances_.push_back(this);
45 }
46 CountedWidget(const CountedWidget& other) : Widget(other) {
47 instances_.push_back(this);
48 }
49 CountedWidget(CountedWidget&& other) noexcept(false)
50 : Widget(std::move(other)) {
51 other.alive = false;
52 other.remove();
53 instances_.push_back(this);
54 }
55 ~CountedWidget() {
56 if (alive) {
57 remove();
58 }
59 }
60
61 private:
62 CountedWidget& operator=(const CountedWidget&) = delete;
63 CountedWidget& operator=(CountedWidget&&) = delete;
64
65 void remove() {
66 auto iter = std::find(instances_.begin(), instances_.end(), this);
67 EXPECT_TRUE(iter != instances_.end());
68 instances_.erase(iter);
69 }
70};
71
72std::vector<Widget*> CountedWidget::instances_;
73} // namespace
74
75TEST(Then, tryConstructor) {
76 auto t = Try<Widget>(23);
77 EXPECT_EQ(t.value().v_, 23);
78 EXPECT_EQ(t.value().copied_, 0);
79 EXPECT_EQ(t.value().moved_, 1);
80}
81
82TEST(Then, makeFuture) {
83 auto future = makeFuture<Widget>(23);
84 EXPECT_EQ(future.value().v_, 23);
85 EXPECT_EQ(future.value().copied_, 0);
86 EXPECT_EQ(future.value().moved_, 2);
87}
88
89TEST(Then, tryConstRValueReference) {
90 auto future = makeFuture<Widget>(23).then([](const Try<Widget>&& t) {
91 EXPECT_EQ(t.value().copied_, 0);
92 EXPECT_EQ(t.value().moved_, 2);
93 return t.value().v_;
94 });
95 EXPECT_EQ(future.value(), 23);
96}
97
98TEST(Then, tryRValueReference) {
99 auto future = makeFuture<Widget>(23).then([](Try<Widget>&& t) {
100 EXPECT_EQ(t.value().copied_, 0);
101 EXPECT_EQ(t.value().moved_, 2);
102 return t.value().v_;
103 });
104 EXPECT_EQ(future.value(), 23);
105}
106
107TEST(Then, tryConstLValueReference) {
108 auto future = makeFuture<Widget>(23).then([](const Try<Widget>& t) {
109 EXPECT_EQ(t.value().copied_, 0);
110 EXPECT_EQ(t.value().moved_, 2);
111 return t.value().v_;
112 });
113 EXPECT_EQ(future.value(), 23);
114}
115
116TEST(Then, tryValue) {
117 auto future = makeFuture<Widget>(23).then([](Try<Widget> t) {
118 EXPECT_EQ(t.value().copied_, 0);
119 EXPECT_EQ(t.value().moved_, 3);
120 return t.value().v_;
121 });
122 EXPECT_EQ(future.value(), 23);
123}
124
125TEST(Then, tryConstValue) {
126 auto future = makeFuture<Widget>(23).then([](const Try<Widget> t) {
127 EXPECT_EQ(t.value().copied_, 0);
128 EXPECT_EQ(t.value().moved_, 3);
129 return t.value().v_;
130 });
131 EXPECT_EQ(future.value(), 23);
132}
133
134TEST(Then, constRValueReference) {
135 auto future = makeFuture<Widget>(23).thenValue([](const Widget&& w) {
136 EXPECT_EQ(w.copied_, 0);
137 EXPECT_EQ(w.moved_, 2);
138 return w.v_;
139 });
140 EXPECT_EQ(future.value(), 23);
141}
142
143TEST(Then, rValueReference) {
144 auto future = makeFuture<Widget>(23).thenValue([](Widget&& w) {
145 EXPECT_EQ(w.copied_, 0);
146 EXPECT_EQ(w.moved_, 2);
147 return w.v_;
148 });
149 EXPECT_EQ(future.value(), 23);
150}
151
152TEST(Then, constLValueReference) {
153 auto future = makeFuture<Widget>(23).thenValue([](const Widget& w) {
154 EXPECT_EQ(w.copied_, 0);
155 EXPECT_EQ(w.moved_, 2);
156 return w.v_;
157 });
158 EXPECT_EQ(future.value(), 23);
159}
160
161TEST(Then, value) {
162 auto future = makeFuture<Widget>(23).thenValue([](Widget w) {
163 EXPECT_EQ(w.copied_, 0);
164 EXPECT_EQ(w.moved_, 3);
165 return w.v_;
166 });
167 EXPECT_EQ(future.value(), 23);
168}
169
170TEST(Then, constValue) {
171 auto future = makeFuture<Widget>(23).thenValue([](const Widget w) {
172 EXPECT_EQ(w.copied_, 0);
173 EXPECT_EQ(w.moved_, 3);
174 return w.v_;
175 });
176 EXPECT_EQ(future.value(), 23);
177}
178
179TEST(Then, objectAliveDuringImmediateNoParamContinuation) {
180 auto f = makeFuture<CountedWidget>(23);
181 auto called = false;
182 std::move(f).thenValue([&](auto&&) {
183 EXPECT_EQ(CountedWidget::instances_.size(), 1u);
184 EXPECT_EQ(CountedWidget::instances_[0]->v_, 23);
185 called = true;
186 });
187 EXPECT_EQ(true, called);
188}
189
190TEST(Then, objectAliveDuringDeferredNoParamContinuation) {
191 auto p = Promise<CountedWidget>{};
192 bool called = false;
193 p.getFuture().thenValue([&](auto&&) {
194 EXPECT_EQ(CountedWidget::instances_.size(), 1u);
195 EXPECT_EQ(CountedWidget::instances_[0]->v_, 23);
196 called = true;
197 });
198 p.setValue(CountedWidget{23});
199 EXPECT_EQ(true, called);
200}
201
202TEST(Then, voidThenShouldPropagateExceptions) {
203 EXPECT_FALSE(makeFuture(42).then().hasException());
204 EXPECT_TRUE(makeFuture<int>(std::runtime_error("err")).then().hasException());
205}
206