调用另一个模拟函数时更改模拟函数的 return 值

Question

假设我有以下模拟

enum class State
{
    IDLE,
    BUSY,
    ERROR1,
    ERROR2
};

class MockActuator : public ActuatorInterface
{
    public:
        MOCK_METHOD0(doAction, void());
        MOCK_METHOD0(getState, State());
};

我正在测试的模块假设如果调用 doAction()，getState() 应该 return BUSY.

如何在 GMock 下对这个假设进行编码？我想将 getState() 保留为模拟函数，因为我需要测试其他 return 值。

我的第一次尝试如下：

    EXPECT_CALL(actuator, doAction()).Times(1).WillOnce(InvokeWithoutArgs(
                [&](){
                    ON_CALL(actuator, getState()).WillByDefault(Return(State::BUSY));
                }));

但这会产生以下神秘错误：

/usr/src/googletest/googlemock/include/gmock/gmock-actions.h:861:64: error: void value not ignored as it ought to be
   Result Perform(const ArgumentTuple&) { return function_impl_(); }

Answer 1

您可以在 docs.

中查看如何执行此操作的示例

关注你的 classes.

首先是模仿原作的假 class：

enum class State
{
    IDLE,
    BUSY,
    ERROR1,
    ERROR2
};

class FakeActuator : public ActuatorInterface
{
    public:
        virtual void doAction () { _state = BUSY; }
        virtual State getState () { return _state; }
    private:
        State _state;
};

之后，模拟 class:

class MockActuator : public ActuatorInterface {
 public:
  // Normal mock method definitions using gMock.
  MOCK_METHOD(void, doAction, (), (override));
  MOCK_METHOD(State, getState, (), (override));

  // Delegates the default actions of the methods to a FakeActuator object.
  // This must be called *before* the custom ON_CALL() statements.
  void DelegateToFake() {
    ON_CALL(*this, doAction).WillByDefault([this]() {
      fake_.doAction();
    });
    ON_CALL(*this, getState).WillByDefault([this]() {
      return fake_.getState();
    });
  }

 private:
  FakeActuator fake_;  // Keeps an instance of the fake in the mock.
};

正是这个“假”对象可以在调用之间保持状态。您还可以根据需要创建尽可能多的“假”classes。

测试：

TEST(AbcTest, Xyz) {
  MockFoo foo;

  foo.DelegateToFake();  // Enables the fake for delegation.

  // Put your ON_CALL(foo, ...)s here, if any.

  // No action specified, meaning to use the default action.
  EXPECT_CALL(foo, doAction());
  EXPECT_CALL(foo, getState());

  foo.doAction();  // FakeActuator::doAction() is invoked.

  EXPECT_EQ(BUSY, foo.getState());  // FakeActuator::getState() is invoked.
}

调用另一个模拟函数时更改模拟函数的 return 值

Change return value of a mock function when another mock function is called

c++

googletest

googlemock