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, try_and_catch_test) {
49 std::string expected = "payload";
51 // Catch rightmost matching exception type
52 exception_wrapper ew = try_and_catch<std::exception, std::runtime_error>(
54 throw std::runtime_error(expected);
56 EXPECT_TRUE(bool(ew));
57 EXPECT_TRUE(ew.getCopied());
58 EXPECT_EQ(ew.what(), "std::runtime_error: payload");
59 auto rep = ew.is_compatible_with<std::runtime_error>();
62 // Changing order is like catching in wrong order. Beware of this in your
64 auto ew2 = try_and_catch<std::runtime_error, std::exception>([=]() {
65 throw std::runtime_error(expected);
67 EXPECT_TRUE(bool(ew2));
68 // We are catching a std::exception, not std::runtime_error.
69 EXPECT_FALSE(ew2.getCopied());
70 // But, we can still get the actual type if we want it.
71 rep = ew2.is_compatible_with<std::runtime_error>();
74 // Catches even if not rightmost.
75 auto ew3 = try_and_catch<std::exception, std::runtime_error>([]() {
76 throw std::exception();
78 EXPECT_TRUE(bool(ew3));
79 EXPECT_NE(ew3.what(), expected);
80 rep = ew3.is_compatible_with<std::runtime_error>();
83 // If does not catch, throws.
85 try_and_catch<std::runtime_error>([]() {
86 throw std::exception();
91 class AbstractIntException : public std::exception {
93 virtual int getInt() const = 0;
96 class IntException : public AbstractIntException {
98 explicit IntException(int i)
101 virtual int getInt() const { return i_; }
102 virtual const char* what() const noexcept override {
103 what_ = folly::to<std::string>("int == ", i_);
104 return what_.c_str();
109 mutable std::string what_;
112 TEST(ExceptionWrapper, with_exception_test) {
115 // This works, and doesn't slice.
116 exception_wrapper ew = try_and_catch<std::exception, std::runtime_error>(
118 throw IntException(expected);
120 EXPECT_TRUE(bool(ew));
121 EXPECT_EQ(ew.what(), "IntException: int == 23");
122 ew.with_exception<IntException>([&](const IntException& ie) {
123 EXPECT_EQ(ie.getInt(), expected);
126 // I can try_and_catch a non-copyable base class. This will use
127 // std::exception_ptr internally.
128 exception_wrapper ew2 = try_and_catch<AbstractIntException>(
130 throw IntException(expected);
132 EXPECT_TRUE(bool(ew2));
133 EXPECT_EQ(ew2.what(), "IntException: int == 23");
134 ew2.with_exception<AbstractIntException>([&](AbstractIntException& ie) {
135 EXPECT_EQ(ie.getInt(), expected);
136 EXPECT_EQ(typeid(ie), typeid(IntException));
140 TEST(ExceptionWrapper, non_std_exception_test) {
143 exception_wrapper ew = try_and_catch<std::exception, int>(
147 EXPECT_TRUE(bool(ew));
148 EXPECT_FALSE(ew.is_compatible_with<std::exception>());
149 EXPECT_EQ(ew.what(), "int");
150 // non-std::exception types are supported, but the only way to
151 // access their value is to explicity rethrow and catch it.
155 EXPECT_EQ(i, expected);