tor-browser

cleanup_test.cc (8249B)

---

// Copyright 2021 The Abseil Authors.
//
// 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
//
//      https://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 "absl/cleanup/cleanup.h"

#include <functional>
#include <type_traits>
#include <utility>

#include "gtest/gtest.h"
#include "absl/base/config.h"
#include "absl/utility/utility.h"

namespace {

using Tag = absl::cleanup_internal::Tag;

template <typename Type1, typename Type2>
constexpr bool IsSame() {
 return (std::is_same<Type1, Type2>::value);
}

struct IdentityFactory {
 template <typename Callback>
 static Callback AsCallback(Callback callback) {
   return Callback(std::move(callback));
 }
};

// `FunctorClass` is a type used for testing `absl::Cleanup`. It is intended to
// represent users that make their own move-only callback types outside of
// `std::function` and lambda literals.
class FunctorClass {
 using Callback = std::function<void()>;

public:
 explicit FunctorClass(Callback callback) : callback_(std::move(callback)) {}

 FunctorClass(FunctorClass&& other)
     : callback_(std::exchange(other.callback_, Callback())) {}

 FunctorClass(const FunctorClass&) = delete;

 FunctorClass& operator=(const FunctorClass&) = delete;

 FunctorClass& operator=(FunctorClass&&) = delete;

 void operator()() const& = delete;

 void operator()() && {
   ASSERT_TRUE(callback_);
   callback_();
   callback_ = nullptr;
 }

private:
 Callback callback_;
};

struct FunctorClassFactory {
 template <typename Callback>
 static FunctorClass AsCallback(Callback callback) {
   return FunctorClass(std::move(callback));
 }
};

struct StdFunctionFactory {
 template <typename Callback>
 static std::function<void()> AsCallback(Callback callback) {
   return std::function<void()>(std::move(callback));
 }
};

using CleanupTestParams =
   ::testing::Types<IdentityFactory, FunctorClassFactory, StdFunctionFactory>;
template <typename>
struct CleanupTest : public ::testing::Test {};
TYPED_TEST_SUITE(CleanupTest, CleanupTestParams);

bool fn_ptr_called = false;
void FnPtrFunction() { fn_ptr_called = true; }

TYPED_TEST(CleanupTest, FactoryProducesCorrectType) {
 {
   auto callback = TypeParam::AsCallback([] {});
   auto cleanup = absl::MakeCleanup(std::move(callback));

   static_assert(
       IsSame<absl::Cleanup<Tag, decltype(callback)>, decltype(cleanup)>(),
       "");
 }

 {
   auto cleanup = absl::MakeCleanup(&FnPtrFunction);

   static_assert(IsSame<absl::Cleanup<Tag, void (*)()>, decltype(cleanup)>(),
                 "");
 }

 {
   auto cleanup = absl::MakeCleanup(FnPtrFunction);

   static_assert(IsSame<absl::Cleanup<Tag, void (*)()>, decltype(cleanup)>(),
                 "");
 }
}

TYPED_TEST(CleanupTest, CTADProducesCorrectType) {
 {
   auto callback = TypeParam::AsCallback([] {});
   absl::Cleanup cleanup = std::move(callback);

   static_assert(
       IsSame<absl::Cleanup<Tag, decltype(callback)>, decltype(cleanup)>(),
       "");
 }

 {
   absl::Cleanup cleanup = &FnPtrFunction;

   static_assert(IsSame<absl::Cleanup<Tag, void (*)()>, decltype(cleanup)>(),
                 "");
 }

 {
   absl::Cleanup cleanup = FnPtrFunction;

   static_assert(IsSame<absl::Cleanup<Tag, void (*)()>, decltype(cleanup)>(),
                 "");
 }
}

TYPED_TEST(CleanupTest, FactoryAndCTADProduceSameType) {
 {
   auto callback = IdentityFactory::AsCallback([] {});
   auto factory_cleanup = absl::MakeCleanup(callback);
   absl::Cleanup deduction_cleanup = callback;

   static_assert(
       IsSame<decltype(factory_cleanup), decltype(deduction_cleanup)>(), "");
 }

 {
   auto factory_cleanup =
       absl::MakeCleanup(FunctorClassFactory::AsCallback([] {}));
   absl::Cleanup deduction_cleanup = FunctorClassFactory::AsCallback([] {});

   static_assert(
       IsSame<decltype(factory_cleanup), decltype(deduction_cleanup)>(), "");
 }

 {
   auto factory_cleanup =
       absl::MakeCleanup(StdFunctionFactory::AsCallback([] {}));
   absl::Cleanup deduction_cleanup = StdFunctionFactory::AsCallback([] {});

   static_assert(
       IsSame<decltype(factory_cleanup), decltype(deduction_cleanup)>(), "");
 }

 {
   auto factory_cleanup = absl::MakeCleanup(&FnPtrFunction);
   absl::Cleanup deduction_cleanup = &FnPtrFunction;

   static_assert(
       IsSame<decltype(factory_cleanup), decltype(deduction_cleanup)>(), "");
 }

 {
   auto factory_cleanup = absl::MakeCleanup(FnPtrFunction);
   absl::Cleanup deduction_cleanup = FnPtrFunction;

   static_assert(
       IsSame<decltype(factory_cleanup), decltype(deduction_cleanup)>(), "");
 }
}

TYPED_TEST(CleanupTest, BasicUsage) {
 bool called = false;

 {
   auto cleanup =
       absl::MakeCleanup(TypeParam::AsCallback([&called] { called = true; }));
   EXPECT_FALSE(called);  // Constructor shouldn't invoke the callback
 }

 EXPECT_TRUE(called);  // Destructor should invoke the callback
}

TYPED_TEST(CleanupTest, BasicUsageWithFunctionPointer) {
 fn_ptr_called = false;

 {
   auto cleanup = absl::MakeCleanup(TypeParam::AsCallback(&FnPtrFunction));
   EXPECT_FALSE(fn_ptr_called);  // Constructor shouldn't invoke the callback
 }

 EXPECT_TRUE(fn_ptr_called);  // Destructor should invoke the callback
}

TYPED_TEST(CleanupTest, Cancel) {
 bool called = false;

 {
   auto cleanup =
       absl::MakeCleanup(TypeParam::AsCallback([&called] { called = true; }));
   EXPECT_FALSE(called);  // Constructor shouldn't invoke the callback

   std::move(cleanup).Cancel();
   EXPECT_FALSE(called);  // Cancel shouldn't invoke the callback
 }

 EXPECT_FALSE(called);  // Destructor shouldn't invoke the callback
}

TYPED_TEST(CleanupTest, Invoke) {
 bool called = false;

 {
   auto cleanup =
       absl::MakeCleanup(TypeParam::AsCallback([&called] { called = true; }));
   EXPECT_FALSE(called);  // Constructor shouldn't invoke the callback

   std::move(cleanup).Invoke();
   EXPECT_TRUE(called);  // Invoke should invoke the callback

   called = false;  // Reset tracker before destructor runs
 }

 EXPECT_FALSE(called);  // Destructor shouldn't invoke the callback
}

TYPED_TEST(CleanupTest, Move) {
 bool called = false;

 {
   auto moved_from_cleanup =
       absl::MakeCleanup(TypeParam::AsCallback([&called] { called = true; }));
   EXPECT_FALSE(called);  // Constructor shouldn't invoke the callback

   {
     auto moved_to_cleanup = std::move(moved_from_cleanup);
     EXPECT_FALSE(called);  // Move shouldn't invoke the callback
   }

   EXPECT_TRUE(called);  // Destructor should invoke the callback

   called = false;  // Reset tracker before destructor runs
 }

 EXPECT_FALSE(called);  // Destructor shouldn't invoke the callback
}

int DestructionCount = 0;

struct DestructionCounter {
 void operator()() {}

 ~DestructionCounter() { ++DestructionCount; }
};

TYPED_TEST(CleanupTest, DestructorDestroys) {
 {
   auto cleanup =
       absl::MakeCleanup(TypeParam::AsCallback(DestructionCounter()));
   DestructionCount = 0;
 }

 EXPECT_EQ(DestructionCount, 1);  // Engaged cleanup destroys
}

TYPED_TEST(CleanupTest, CancelDestroys) {
 {
   auto cleanup =
       absl::MakeCleanup(TypeParam::AsCallback(DestructionCounter()));
   DestructionCount = 0;

   std::move(cleanup).Cancel();
   EXPECT_EQ(DestructionCount, 1);  // Cancel destroys
 }

 EXPECT_EQ(DestructionCount, 1);  // Canceled cleanup does not double destroy
}

TYPED_TEST(CleanupTest, InvokeDestroys) {
 {
   auto cleanup =
       absl::MakeCleanup(TypeParam::AsCallback(DestructionCounter()));
   DestructionCount = 0;

   std::move(cleanup).Invoke();
   EXPECT_EQ(DestructionCount, 1);  // Invoke destroys
 }

 EXPECT_EQ(DestructionCount, 1);  // Invoked cleanup does not double destroy
}

}  // namespace