Tom Cherry | 11a3aee | 2017-08-03 12:54:07 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2017 The Android Open Source Project |
| 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 "result.h" |
| 18 | |
| 19 | #include "errno.h" |
| 20 | |
| 21 | #include <string> |
| 22 | |
| 23 | #include <gtest/gtest.h> |
| 24 | |
| 25 | using namespace std::string_literals; |
| 26 | |
| 27 | namespace android { |
| 28 | namespace init { |
| 29 | |
| 30 | TEST(result, result_accessors) { |
| 31 | Result<std::string> result = "success"; |
| 32 | ASSERT_TRUE(result); |
| 33 | ASSERT_TRUE(result.has_value()); |
| 34 | |
| 35 | EXPECT_EQ("success", *result); |
| 36 | EXPECT_EQ("success", result.value()); |
| 37 | |
| 38 | EXPECT_EQ('s', result->data()[0]); |
| 39 | } |
| 40 | |
| 41 | TEST(result, result_accessors_rvalue) { |
| 42 | ASSERT_TRUE(Result<std::string>("success")); |
| 43 | ASSERT_TRUE(Result<std::string>("success").has_value()); |
| 44 | |
| 45 | EXPECT_EQ("success", *Result<std::string>("success")); |
| 46 | EXPECT_EQ("success", Result<std::string>("success").value()); |
| 47 | |
| 48 | EXPECT_EQ('s', Result<std::string>("success")->data()[0]); |
| 49 | } |
| 50 | |
| 51 | TEST(result, result_success) { |
| 52 | Result<Success> result = Success(); |
| 53 | ASSERT_TRUE(result); |
| 54 | ASSERT_TRUE(result.has_value()); |
| 55 | |
| 56 | EXPECT_EQ(Success(), *result); |
| 57 | EXPECT_EQ(Success(), result.value()); |
| 58 | } |
| 59 | |
| 60 | TEST(result, result_success_rvalue) { |
| 61 | // Success() doesn't actually create a Result<Success> object, but rather an object that can be |
| 62 | // implicitly constructed into a Result<Success> object. |
| 63 | |
| 64 | auto MakeRvalueSuccessResult = []() -> Result<Success> { return Success(); }; |
| 65 | ASSERT_TRUE(MakeRvalueSuccessResult()); |
| 66 | ASSERT_TRUE(MakeRvalueSuccessResult().has_value()); |
| 67 | |
| 68 | EXPECT_EQ(Success(), *MakeRvalueSuccessResult()); |
| 69 | EXPECT_EQ(Success(), MakeRvalueSuccessResult().value()); |
| 70 | } |
| 71 | |
| 72 | TEST(result, result_error) { |
| 73 | Result<Success> result = Error() << "failure" << 1; |
| 74 | ASSERT_FALSE(result); |
| 75 | ASSERT_FALSE(result.has_value()); |
| 76 | |
Tom Cherry | 130e3d7 | 2017-08-22 16:07:15 -0700 | [diff] [blame] | 77 | EXPECT_EQ(0, result.error_errno()); |
| 78 | EXPECT_EQ("failure1", result.error_string()); |
Tom Cherry | 11a3aee | 2017-08-03 12:54:07 -0700 | [diff] [blame] | 79 | } |
| 80 | |
| 81 | TEST(result, result_error_empty) { |
| 82 | Result<Success> result = Error(); |
| 83 | ASSERT_FALSE(result); |
| 84 | ASSERT_FALSE(result.has_value()); |
| 85 | |
Tom Cherry | 130e3d7 | 2017-08-22 16:07:15 -0700 | [diff] [blame] | 86 | EXPECT_EQ(0, result.error_errno()); |
| 87 | EXPECT_EQ("", result.error_string()); |
Tom Cherry | 11a3aee | 2017-08-03 12:54:07 -0700 | [diff] [blame] | 88 | } |
| 89 | |
| 90 | TEST(result, result_error_rvalue) { |
| 91 | // Error() and ErrnoError() aren't actually used to create a Result<T> object. |
| 92 | // Under the hood, they are an intermediate class that can be implicitly constructed into a |
| 93 | // Result<T>. This is needed both to create the ostream and because Error() itself, by |
| 94 | // definition will not know what the type, T, of the underlying Result<T> object that it would |
| 95 | // create is. |
| 96 | |
| 97 | auto MakeRvalueErrorResult = []() -> Result<Success> { return Error() << "failure" << 1; }; |
| 98 | ASSERT_FALSE(MakeRvalueErrorResult()); |
| 99 | ASSERT_FALSE(MakeRvalueErrorResult().has_value()); |
| 100 | |
Tom Cherry | 130e3d7 | 2017-08-22 16:07:15 -0700 | [diff] [blame] | 101 | EXPECT_EQ(0, MakeRvalueErrorResult().error_errno()); |
| 102 | EXPECT_EQ("failure1", MakeRvalueErrorResult().error_string()); |
Tom Cherry | 11a3aee | 2017-08-03 12:54:07 -0700 | [diff] [blame] | 103 | } |
| 104 | |
| 105 | TEST(result, result_errno_error) { |
| 106 | constexpr int test_errno = 6; |
| 107 | errno = test_errno; |
| 108 | Result<Success> result = ErrnoError() << "failure" << 1; |
| 109 | |
| 110 | ASSERT_FALSE(result); |
| 111 | ASSERT_FALSE(result.has_value()); |
| 112 | |
Tom Cherry | 130e3d7 | 2017-08-22 16:07:15 -0700 | [diff] [blame] | 113 | EXPECT_EQ(test_errno, result.error_errno()); |
| 114 | EXPECT_EQ("failure1: "s + strerror(test_errno), result.error_string()); |
| 115 | } |
| 116 | |
| 117 | TEST(result, result_errno_error_no_text) { |
| 118 | constexpr int test_errno = 6; |
| 119 | errno = test_errno; |
| 120 | Result<Success> result = ErrnoError(); |
| 121 | |
| 122 | ASSERT_FALSE(result); |
| 123 | ASSERT_FALSE(result.has_value()); |
| 124 | |
| 125 | EXPECT_EQ(test_errno, result.error_errno()); |
| 126 | EXPECT_EQ(strerror(test_errno), result.error_string()); |
| 127 | } |
| 128 | |
| 129 | TEST(result, result_error_from_other_result) { |
| 130 | auto error_text = "test error"s; |
| 131 | Result<Success> result = Error() << error_text; |
| 132 | |
| 133 | ASSERT_FALSE(result); |
| 134 | ASSERT_FALSE(result.has_value()); |
| 135 | |
| 136 | Result<std::string> result2 = result.error(); |
| 137 | |
| 138 | ASSERT_FALSE(result2); |
| 139 | ASSERT_FALSE(result2.has_value()); |
| 140 | |
| 141 | EXPECT_EQ(0, result.error_errno()); |
| 142 | EXPECT_EQ(error_text, result.error_string()); |
| 143 | } |
| 144 | |
| 145 | TEST(result, result_error_through_ostream) { |
| 146 | auto error_text = "test error"s; |
| 147 | Result<Success> result = Error() << error_text; |
| 148 | |
| 149 | ASSERT_FALSE(result); |
| 150 | ASSERT_FALSE(result.has_value()); |
| 151 | |
| 152 | Result<std::string> result2 = Error() << result.error(); |
| 153 | |
| 154 | ASSERT_FALSE(result2); |
| 155 | ASSERT_FALSE(result2.has_value()); |
| 156 | |
| 157 | EXPECT_EQ(0, result.error_errno()); |
| 158 | EXPECT_EQ(error_text, result.error_string()); |
| 159 | } |
| 160 | |
| 161 | TEST(result, result_errno_error_through_ostream) { |
| 162 | auto error_text = "test error"s; |
| 163 | constexpr int test_errno = 6; |
| 164 | errno = 6; |
| 165 | Result<Success> result = ErrnoError() << error_text; |
| 166 | |
| 167 | errno = 0; |
| 168 | |
| 169 | ASSERT_FALSE(result); |
| 170 | ASSERT_FALSE(result.has_value()); |
| 171 | |
| 172 | Result<std::string> result2 = Error() << result.error(); |
| 173 | |
| 174 | ASSERT_FALSE(result2); |
| 175 | ASSERT_FALSE(result2.has_value()); |
| 176 | |
| 177 | EXPECT_EQ(test_errno, result.error_errno()); |
| 178 | EXPECT_EQ(error_text + ": " + strerror(test_errno), result.error_string()); |
Tom Cherry | 11a3aee | 2017-08-03 12:54:07 -0700 | [diff] [blame] | 179 | } |
| 180 | |
| 181 | TEST(result, constructor_forwarding) { |
| 182 | auto result = Result<std::string>(5, 'a'); |
| 183 | |
| 184 | ASSERT_TRUE(result); |
| 185 | ASSERT_TRUE(result.has_value()); |
| 186 | |
| 187 | EXPECT_EQ("aaaaa", *result); |
| 188 | } |
| 189 | |
| 190 | struct ConstructorTracker { |
| 191 | static size_t constructor_called; |
| 192 | static size_t copy_constructor_called; |
| 193 | static size_t move_constructor_called; |
| 194 | static size_t copy_assignment_called; |
| 195 | static size_t move_assignment_called; |
| 196 | |
| 197 | template <typename T> |
| 198 | ConstructorTracker(T&& string) : string(string) { |
| 199 | ++constructor_called; |
| 200 | } |
| 201 | |
| 202 | ConstructorTracker(const ConstructorTracker& ct) { |
| 203 | ++copy_constructor_called; |
| 204 | string = ct.string; |
| 205 | } |
| 206 | ConstructorTracker(ConstructorTracker&& ct) noexcept { |
| 207 | ++move_constructor_called; |
| 208 | string = std::move(ct.string); |
| 209 | } |
| 210 | ConstructorTracker& operator=(const ConstructorTracker& ct) { |
| 211 | ++copy_assignment_called; |
| 212 | string = ct.string; |
| 213 | return *this; |
| 214 | } |
| 215 | ConstructorTracker& operator=(ConstructorTracker&& ct) noexcept { |
| 216 | ++move_assignment_called; |
| 217 | string = std::move(ct.string); |
| 218 | return *this; |
| 219 | } |
| 220 | |
| 221 | std::string string; |
| 222 | }; |
| 223 | |
| 224 | size_t ConstructorTracker::constructor_called = 0; |
| 225 | size_t ConstructorTracker::copy_constructor_called = 0; |
| 226 | size_t ConstructorTracker::move_constructor_called = 0; |
| 227 | size_t ConstructorTracker::copy_assignment_called = 0; |
| 228 | size_t ConstructorTracker::move_assignment_called = 0; |
| 229 | |
| 230 | Result<ConstructorTracker> ReturnConstructorTracker(const std::string& in) { |
| 231 | if (in.empty()) { |
| 232 | return "literal string"; |
| 233 | } |
| 234 | if (in == "test2") { |
| 235 | return ConstructorTracker(in + in + "2"); |
| 236 | } |
| 237 | ConstructorTracker result(in + " " + in); |
| 238 | return result; |
| 239 | }; |
| 240 | |
| 241 | TEST(result, no_copy_on_return) { |
| 242 | // If returning parameters that may be used to implicitly construct the type T of Result<T>, |
| 243 | // then those parameters are forwarded to the construction of Result<T>. |
| 244 | |
| 245 | // If returning an prvalue or xvalue, it will be move constructed during the construction of |
| 246 | // Result<T>. |
| 247 | |
| 248 | // This check ensures that that is the case, and particularly that no copy constructors |
| 249 | // are called. |
| 250 | |
| 251 | auto result1 = ReturnConstructorTracker(""); |
| 252 | ASSERT_TRUE(result1); |
| 253 | EXPECT_EQ("literal string", result1->string); |
| 254 | EXPECT_EQ(1U, ConstructorTracker::constructor_called); |
| 255 | EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called); |
| 256 | EXPECT_EQ(0U, ConstructorTracker::move_constructor_called); |
| 257 | EXPECT_EQ(0U, ConstructorTracker::copy_assignment_called); |
| 258 | EXPECT_EQ(0U, ConstructorTracker::move_assignment_called); |
| 259 | |
| 260 | auto result2 = ReturnConstructorTracker("test2"); |
| 261 | ASSERT_TRUE(result2); |
| 262 | EXPECT_EQ("test2test22", result2->string); |
| 263 | EXPECT_EQ(2U, ConstructorTracker::constructor_called); |
| 264 | EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called); |
| 265 | EXPECT_EQ(1U, ConstructorTracker::move_constructor_called); |
| 266 | EXPECT_EQ(0U, ConstructorTracker::copy_assignment_called); |
| 267 | EXPECT_EQ(0U, ConstructorTracker::move_assignment_called); |
| 268 | |
| 269 | auto result3 = ReturnConstructorTracker("test3"); |
| 270 | ASSERT_TRUE(result3); |
| 271 | EXPECT_EQ("test3 test3", result3->string); |
| 272 | EXPECT_EQ(3U, ConstructorTracker::constructor_called); |
| 273 | EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called); |
| 274 | EXPECT_EQ(2U, ConstructorTracker::move_constructor_called); |
| 275 | EXPECT_EQ(0U, ConstructorTracker::copy_assignment_called); |
| 276 | EXPECT_EQ(0U, ConstructorTracker::move_assignment_called); |
| 277 | } |
| 278 | |
Tom Cherry | d1c9cd0 | 2017-09-12 14:44:56 -0700 | [diff] [blame] | 279 | // Below two tests require that we do not hide the move constructor with our forwarding reference |
| 280 | // constructor. This is done with by disabling the forwarding reference constructor if its first |
| 281 | // and only type is Result<T>. |
| 282 | TEST(result, result_result_with_success) { |
| 283 | auto return_result_result_with_success = []() -> Result<Result<Success>> { |
| 284 | return Result<Success>(); |
| 285 | }; |
| 286 | auto result = return_result_result_with_success(); |
| 287 | ASSERT_TRUE(result); |
| 288 | ASSERT_TRUE(*result); |
| 289 | |
| 290 | auto inner_result = result.value(); |
| 291 | ASSERT_TRUE(inner_result); |
| 292 | } |
| 293 | |
| 294 | TEST(result, result_result_with_failure) { |
| 295 | auto return_result_result_with_error = []() -> Result<Result<Success>> { |
| 296 | return Result<Success>(ResultError("failure string", 6)); |
| 297 | }; |
| 298 | auto result = return_result_result_with_error(); |
| 299 | ASSERT_TRUE(result); |
| 300 | ASSERT_FALSE(*result); |
| 301 | EXPECT_EQ("failure string", result->error_string()); |
| 302 | EXPECT_EQ(6, result->error_errno()); |
| 303 | } |
| 304 | |
| 305 | // This test requires that we disable the forwarding reference constructor if Result<T> is the |
| 306 | // *only* type that we are forwarding. In otherwords, if we are forwarding Result<T>, int to |
| 307 | // construct a Result<T>, then we still need the constructor. |
| 308 | TEST(result, result_two_parameter_constructor_same_type) { |
| 309 | struct TestStruct { |
| 310 | TestStruct(int value) : value_(value) {} |
| 311 | TestStruct(Result<TestStruct> result, int value) : value_(result->value_ * value) {} |
| 312 | int value_; |
| 313 | }; |
| 314 | |
| 315 | auto return_test_struct = []() -> Result<TestStruct> { return {Result<TestStruct>(6), 6}; }; |
| 316 | |
| 317 | auto result = return_test_struct(); |
| 318 | ASSERT_TRUE(result); |
| 319 | EXPECT_EQ(36, result->value_); |
| 320 | } |
| 321 | |
Tom Cherry | 11a3aee | 2017-08-03 12:54:07 -0700 | [diff] [blame] | 322 | TEST(result, die_on_access_failed_result) { |
| 323 | Result<std::string> result = Error(); |
| 324 | ASSERT_DEATH(*result, ""); |
| 325 | } |
| 326 | |
| 327 | TEST(result, die_on_get_error_succesful_result) { |
| 328 | Result<std::string> result = "success"; |
Tom Cherry | 130e3d7 | 2017-08-22 16:07:15 -0700 | [diff] [blame] | 329 | ASSERT_DEATH(result.error_string(), ""); |
Tom Cherry | 11a3aee | 2017-08-03 12:54:07 -0700 | [diff] [blame] | 330 | } |
| 331 | |
| 332 | } // namespace init |
| 333 | } // namespace android |