/*
* Copyright (C) 2017 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "result.h"
#include "errno.h"
#include <string>
#include <gtest/gtest.h>
using namespace std::string_literals;
namespace android {
namespace init {
TEST(result, result_accessors) {
Result<std::string> result = "success";
ASSERT_TRUE(result);
ASSERT_TRUE(result.has_value());
EXPECT_EQ("success", *result);
EXPECT_EQ("success", result.value());
EXPECT_EQ('s', result->data()[0]);
}
TEST(result, result_accessors_rvalue) {
ASSERT_TRUE(Result<std::string>("success"));
ASSERT_TRUE(Result<std::string>("success").has_value());
EXPECT_EQ("success", *Result<std::string>("success"));
EXPECT_EQ("success", Result<std::string>("success").value());
EXPECT_EQ('s', Result<std::string>("success")->data()[0]);
}
TEST(result, result_success) {
Result<Success> result = Success();
ASSERT_TRUE(result);
ASSERT_TRUE(result.has_value());
EXPECT_EQ(Success(), *result);
EXPECT_EQ(Success(), result.value());
}
TEST(result, result_success_rvalue) {
// Success() doesn't actually create a Result<Success> object, but rather an object that can be
// implicitly constructed into a Result<Success> object.
auto MakeRvalueSuccessResult = []() -> Result<Success> { return Success(); };
ASSERT_TRUE(MakeRvalueSuccessResult());
ASSERT_TRUE(MakeRvalueSuccessResult().has_value());
EXPECT_EQ(Success(), *MakeRvalueSuccessResult());
EXPECT_EQ(Success(), MakeRvalueSuccessResult().value());
}
TEST(result, result_error) {
Result<Success> result = Error() << "failure" << 1;
ASSERT_FALSE(result);
ASSERT_FALSE(result.has_value());
EXPECT_EQ(0, result.error_errno());
EXPECT_EQ("failure1", result.error_string());
}
TEST(result, result_error_empty) {
Result<Success> result = Error();
ASSERT_FALSE(result);
ASSERT_FALSE(result.has_value());
EXPECT_EQ(0, result.error_errno());
EXPECT_EQ("", result.error_string());
}
TEST(result, result_error_rvalue) {
// Error() and ErrnoError() aren't actually used to create a Result<T> object.
// Under the hood, they are an intermediate class that can be implicitly constructed into a
// Result<T>. This is needed both to create the ostream and because Error() itself, by
// definition will not know what the type, T, of the underlying Result<T> object that it would
// create is.
auto MakeRvalueErrorResult = []() -> Result<Success> { return Error() << "failure" << 1; };
ASSERT_FALSE(MakeRvalueErrorResult());
ASSERT_FALSE(MakeRvalueErrorResult().has_value());
EXPECT_EQ(0, MakeRvalueErrorResult().error_errno());
EXPECT_EQ("failure1", MakeRvalueErrorResult().error_string());
}
TEST(result, result_errno_error) {
constexpr int test_errno = 6;
errno = test_errno;
Result<Success> result = ErrnoError() << "failure" << 1;
ASSERT_FALSE(result);
ASSERT_FALSE(result.has_value());
EXPECT_EQ(test_errno, result.error_errno());
EXPECT_EQ("failure1: "s + strerror(test_errno), result.error_string());
}
TEST(result, result_errno_error_no_text) {
constexpr int test_errno = 6;
errno = test_errno;
Result<Success> result = ErrnoError();
ASSERT_FALSE(result);
ASSERT_FALSE(result.has_value());
EXPECT_EQ(test_errno, result.error_errno());
EXPECT_EQ(strerror(test_errno), result.error_string());
}
TEST(result, result_error_from_other_result) {
auto error_text = "test error"s;
Result<Success> result = Error() << error_text;
ASSERT_FALSE(result);
ASSERT_FALSE(result.has_value());
Result<std::string> result2 = result.error();
ASSERT_FALSE(result2);
ASSERT_FALSE(result2.has_value());
EXPECT_EQ(0, result.error_errno());
EXPECT_EQ(error_text, result.error_string());
}
TEST(result, result_error_through_ostream) {
auto error_text = "test error"s;
Result<Success> result = Error() << error_text;
ASSERT_FALSE(result);
ASSERT_FALSE(result.has_value());
Result<std::string> result2 = Error() << result.error();
ASSERT_FALSE(result2);
ASSERT_FALSE(result2.has_value());
EXPECT_EQ(0, result.error_errno());
EXPECT_EQ(error_text, result.error_string());
}
TEST(result, result_errno_error_through_ostream) {
auto error_text = "test error"s;
constexpr int test_errno = 6;
errno = 6;
Result<Success> result = ErrnoError() << error_text;
errno = 0;
ASSERT_FALSE(result);
ASSERT_FALSE(result.has_value());
Result<std::string> result2 = Error() << result.error();
ASSERT_FALSE(result2);
ASSERT_FALSE(result2.has_value());
EXPECT_EQ(test_errno, result.error_errno());
EXPECT_EQ(error_text + ": " + strerror(test_errno), result.error_string());
}
TEST(result, constructor_forwarding) {
auto result = Result<std::string>(5, 'a');
ASSERT_TRUE(result);
ASSERT_TRUE(result.has_value());
EXPECT_EQ("aaaaa", *result);
}
struct ConstructorTracker {
static size_t constructor_called;
static size_t copy_constructor_called;
static size_t move_constructor_called;
static size_t copy_assignment_called;
static size_t move_assignment_called;
template <typename T>
ConstructorTracker(T&& string) : string(string) {
++constructor_called;
}
ConstructorTracker(const ConstructorTracker& ct) {
++copy_constructor_called;
string = ct.string;
}
ConstructorTracker(ConstructorTracker&& ct) noexcept {
++move_constructor_called;
string = std::move(ct.string);
}
ConstructorTracker& operator=(const ConstructorTracker& ct) {
++copy_assignment_called;
string = ct.string;
return *this;
}
ConstructorTracker& operator=(ConstructorTracker&& ct) noexcept {
++move_assignment_called;
string = std::move(ct.string);
return *this;
}
std::string string;
};
size_t ConstructorTracker::constructor_called = 0;
size_t ConstructorTracker::copy_constructor_called = 0;
size_t ConstructorTracker::move_constructor_called = 0;
size_t ConstructorTracker::copy_assignment_called = 0;
size_t ConstructorTracker::move_assignment_called = 0;
Result<ConstructorTracker> ReturnConstructorTracker(const std::string& in) {
if (in.empty()) {
return "literal string";
}
if (in == "test2") {
return ConstructorTracker(in + in + "2");
}
ConstructorTracker result(in + " " + in);
return result;
};
TEST(result, no_copy_on_return) {
// If returning parameters that may be used to implicitly construct the type T of Result<T>,
// then those parameters are forwarded to the construction of Result<T>.
// If returning an prvalue or xvalue, it will be move constructed during the construction of
// Result<T>.
// This check ensures that that is the case, and particularly that no copy constructors
// are called.
auto result1 = ReturnConstructorTracker("");
ASSERT_TRUE(result1);
EXPECT_EQ("literal string", result1->string);
EXPECT_EQ(1U, ConstructorTracker::constructor_called);
EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called);
EXPECT_EQ(0U, ConstructorTracker::move_constructor_called);
EXPECT_EQ(0U, ConstructorTracker::copy_assignment_called);
EXPECT_EQ(0U, ConstructorTracker::move_assignment_called);
auto result2 = ReturnConstructorTracker("test2");
ASSERT_TRUE(result2);
EXPECT_EQ("test2test22", result2->string);
EXPECT_EQ(2U, ConstructorTracker::constructor_called);
EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called);
EXPECT_EQ(1U, ConstructorTracker::move_constructor_called);
EXPECT_EQ(0U, ConstructorTracker::copy_assignment_called);
EXPECT_EQ(0U, ConstructorTracker::move_assignment_called);
auto result3 = ReturnConstructorTracker("test3");
ASSERT_TRUE(result3);
EXPECT_EQ("test3 test3", result3->string);
EXPECT_EQ(3U, ConstructorTracker::constructor_called);
EXPECT_EQ(0U, ConstructorTracker::copy_constructor_called);
EXPECT_EQ(2U, ConstructorTracker::move_constructor_called);
EXPECT_EQ(0U, ConstructorTracker::copy_assignment_called);
EXPECT_EQ(0U, ConstructorTracker::move_assignment_called);
}
// Below two tests require that we do not hide the move constructor with our forwarding reference
// constructor. This is done with by disabling the forwarding reference constructor if its first
// and only type is Result<T>.
TEST(result, result_result_with_success) {
auto return_result_result_with_success = []() -> Result<Result<Success>> {
return Result<Success>();
};
auto result = return_result_result_with_success();
ASSERT_TRUE(result);
ASSERT_TRUE(*result);
auto inner_result = result.value();
ASSERT_TRUE(inner_result);
}
TEST(result, result_result_with_failure) {
auto return_result_result_with_error = []() -> Result<Result<Success>> {
return Result<Success>(ResultError("failure string", 6));
};
auto result = return_result_result_with_error();
ASSERT_TRUE(result);
ASSERT_FALSE(*result);
EXPECT_EQ("failure string", result->error_string());
EXPECT_EQ(6, result->error_errno());
}
// This test requires that we disable the forwarding reference constructor if Result<T> is the
// *only* type that we are forwarding. In otherwords, if we are forwarding Result<T>, int to
// construct a Result<T>, then we still need the constructor.
TEST(result, result_two_parameter_constructor_same_type) {
struct TestStruct {
TestStruct(int value) : value_(value) {}
TestStruct(Result<TestStruct> result, int value) : value_(result->value_ * value) {}
int value_;
};
auto return_test_struct = []() -> Result<TestStruct> { return {Result<TestStruct>(6), 6}; };
auto result = return_test_struct();
ASSERT_TRUE(result);
EXPECT_EQ(36, result->value_);
}
TEST(result, die_on_access_failed_result) {
Result<std::string> result = Error();
ASSERT_DEATH(*result, "");
}
TEST(result, die_on_get_error_succesful_result) {
Result<std::string> result = "success";
ASSERT_DEATH(result.error_string(), "");
}
} // namespace init
} // namespace android
