init/result_test.cpp - android-core - Git at Google

 /*
  * 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
	/*
	* 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