| // Copyright 2020 The Dawn 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 |
| // |
| // 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. |
| |
| #ifndef SRC_DAWN_TESTS_MOCKCALLBACK_H_ |
| #define SRC_DAWN_TESTS_MOCKCALLBACK_H_ |
| |
| #include <memory> |
| #include <set> |
| #include <tuple> |
| #include <utility> |
| |
| #include "dawn/common/Assert.h" |
| #include "gmock/gmock.h" |
| |
| namespace testing { |
| |
| template <typename F> |
| class MockCallback; |
| |
| // Helper class for mocking callbacks used for Dawn callbacks with |void* userdata| |
| // as the last callback argument. |
| // |
| // Example Usage: |
| // MockCallback<WGPUDeviceLostCallback> mock; |
| // |
| // void* foo = XYZ; // this is the callback userdata |
| // |
| // wgpuDeviceSetDeviceLostCallback(device, mock.Callback(), mock.MakeUserdata(foo)); |
| // EXPECT_CALL(mock, Call(_, foo)); |
| template <typename R, typename... Args> |
| class MockCallback<R (*)(Args...)> : public ::testing::MockFunction<R(Args...)> { |
| using CallbackType = R (*)(Args...); |
| |
| public: |
| // Helper function makes it easier to get the callback using |foo.Callback()| |
| // unstead of MockCallback<CallbackType>::Callback. |
| static CallbackType Callback() { return CallUnboundCallback; } |
| |
| void* MakeUserdata(void* userdata) { |
| auto mockAndUserdata = |
| std::unique_ptr<MockAndUserdata>(new MockAndUserdata{this, userdata}); |
| |
| // Add the userdata to a set of userdata for this mock. We never |
| // remove from this set even if a callback should only be called once so that |
| // repeated calls to the callback still forward the userdata correctly. |
| // Userdata will be destroyed when the mock is destroyed. |
| auto [result, inserted] = mUserdatas.insert(std::move(mockAndUserdata)); |
| ASSERT(inserted); |
| return result->get(); |
| } |
| |
| private: |
| struct MockAndUserdata { |
| MockCallback* mock; |
| void* userdata; |
| }; |
| |
| static R CallUnboundCallback(Args... args) { |
| std::tuple<Args...> tuple = std::make_tuple(args...); |
| |
| constexpr size_t ArgC = sizeof...(Args); |
| static_assert(ArgC >= 1, "Mock callback requires at least one argument (the userdata)"); |
| |
| // Get the userdata. It should be the last argument. |
| auto userdata = std::get<ArgC - 1>(tuple); |
| static_assert(std::is_same<decltype(userdata), void*>::value, |
| "Last callback argument must be void* userdata"); |
| |
| // Extract the mock. |
| ASSERT(userdata != nullptr); |
| auto* mockAndUserdata = reinterpret_cast<MockAndUserdata*>(userdata); |
| MockCallback* mock = mockAndUserdata->mock; |
| ASSERT(mock != nullptr); |
| |
| // Replace the userdata |
| std::get<ArgC - 1>(tuple) = mockAndUserdata->userdata; |
| |
| // Forward the callback to the mock. |
| return mock->CallImpl(std::make_index_sequence<ArgC>{}, std::move(tuple)); |
| } |
| |
| // This helper cannot be inlined because we dependent on the templated index sequence |
| // to unpack the tuple arguments. |
| template <size_t... Is> |
| R CallImpl(const std::index_sequence<Is...>&, std::tuple<Args...> args) { |
| return this->Call(std::get<Is>(args)...); |
| } |
| |
| std::set<std::unique_ptr<MockAndUserdata>> mUserdatas; |
| }; |
| |
| } // namespace testing |
| |
| #endif // SRC_DAWN_TESTS_MOCKCALLBACK_H_ |