2 * Copyright 2014 Facebook, Inc.
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 #include <gtest/gtest.h>
19 #include <folly/ExceptionWrapper.h>
20 #include <folly/Conv.h>
22 using namespace folly;
24 // Tests that when we call throwException, the proper type is thrown (derived)
25 TEST(ExceptionWrapper, throw_test) {
26 std::runtime_error e("payload");
27 auto ew = make_exception_wrapper<std::runtime_error>(e);
29 std::vector<exception_wrapper> container;
30 container.push_back(ew);
33 container[0].throwException();
34 } catch (std::runtime_error& e) {
35 std::string expected = "payload";
36 std::string actual = e.what();
37 EXPECT_EQ(expected, actual);
41 TEST(ExceptionWrapper, boolean) {
42 auto ew = exception_wrapper();
43 EXPECT_FALSE(bool(ew));
44 ew = make_exception_wrapper<std::runtime_error>("payload");
45 EXPECT_TRUE(bool(ew));
48 TEST(ExceptionWrapper, equals) {
49 std::runtime_error e("payload");
50 auto ew1 = make_exception_wrapper<std::runtime_error>(e);
54 auto ew3 = try_and_catch<std::exception>([&]() {
55 throw std::runtime_error("payload");
57 auto ew4 = try_and_catch<std::exception>([&]() {
63 TEST(ExceptionWrapper, not_equals) {
64 std::runtime_error e1("payload");
65 std::runtime_error e2("payload");
66 auto ew1 = make_exception_wrapper<std::runtime_error>(e1);
67 auto ew2 = make_exception_wrapper<std::runtime_error>(e2);
70 auto ew3 = make_exception_wrapper<std::runtime_error>(e1);
71 auto ew4 = make_exception_wrapper<std::runtime_error>(e1);
74 auto ew5 = try_and_catch<std::exception>([&]() {
77 auto ew6 = try_and_catch<std::exception>([&]() {
83 TEST(ExceptionWrapper, try_and_catch_test) {
84 std::string expected = "payload";
86 // Catch rightmost matching exception type
87 exception_wrapper ew = try_and_catch<std::exception, std::runtime_error>(
89 throw std::runtime_error(expected);
91 EXPECT_TRUE(bool(ew));
92 EXPECT_TRUE(ew.getCopied());
93 EXPECT_EQ(ew.what(), "std::runtime_error: payload");
94 auto rep = ew.is_compatible_with<std::runtime_error>();
97 // Changing order is like catching in wrong order. Beware of this in your
99 auto ew2 = try_and_catch<std::runtime_error, std::exception>([=]() {
100 throw std::runtime_error(expected);
102 EXPECT_TRUE(bool(ew2));
103 // We are catching a std::exception, not std::runtime_error.
104 EXPECT_FALSE(ew2.getCopied());
105 // But, we can still get the actual type if we want it.
106 rep = ew2.is_compatible_with<std::runtime_error>();
109 // Catches even if not rightmost.
110 auto ew3 = try_and_catch<std::exception, std::runtime_error>([]() {
111 throw std::exception();
113 EXPECT_TRUE(bool(ew3));
114 EXPECT_NE(ew3.what(), expected);
115 rep = ew3.is_compatible_with<std::runtime_error>();
118 // If does not catch, throws.
120 try_and_catch<std::runtime_error>([]() {
121 throw std::exception();
126 class AbstractIntException : public std::exception {
128 virtual int getInt() const = 0;
131 class IntException : public AbstractIntException {
133 explicit IntException(int i)
136 virtual int getInt() const { return i_; }
137 virtual const char* what() const noexcept override {
138 what_ = folly::to<std::string>("int == ", i_);
139 return what_.c_str();
144 mutable std::string what_;
147 TEST(ExceptionWrapper, with_exception_test) {
150 // This works, and doesn't slice.
151 exception_wrapper ew = try_and_catch<std::exception, std::runtime_error>(
153 throw IntException(expected);
155 EXPECT_TRUE(bool(ew));
156 EXPECT_EQ(ew.what(), "IntException: int == 23");
157 ew.with_exception<IntException>([&](const IntException& ie) {
158 EXPECT_EQ(ie.getInt(), expected);
161 // I can try_and_catch a non-copyable base class. This will use
162 // std::exception_ptr internally.
163 exception_wrapper ew2 = try_and_catch<AbstractIntException>(
165 throw IntException(expected);
167 EXPECT_TRUE(bool(ew2));
168 EXPECT_EQ(ew2.what(), "IntException: int == 23");
169 ew2.with_exception<AbstractIntException>([&](AbstractIntException& ie) {
170 EXPECT_EQ(ie.getInt(), expected);
171 EXPECT_EQ(typeid(ie), typeid(IntException));
174 // Test with const this. If this compiles and does not crash due to
175 // infinite loop when it runs, it succeeds.
176 const exception_wrapper& cew = ew;
177 cew.with_exception<IntException>([&](const IntException& ie) {
181 // This won't even compile. You can't use a function which takes a
182 // non-const reference with a const exception_wrapper.
184 cew.with_exception<IntException>([&](IntException& ie) {
190 TEST(ExceptionWrapper, non_std_exception_test) {
193 exception_wrapper ew = try_and_catch<std::exception, int>(
197 EXPECT_TRUE(bool(ew));
198 EXPECT_FALSE(ew.is_compatible_with<std::exception>());
199 EXPECT_EQ(ew.what(), "int");
200 // non-std::exception types are supported, but the only way to
201 // access their value is to explicity rethrow and catch it.
205 EXPECT_EQ(i, expected);