Can I copy a google mock object after setting expectations?

Question

I want to add a utility function in my test fixture class that will return a mock with particular expectations/actions set.

E.g.:

class MockListener: public Listener
{
    // Google mock method.
};

class MyTest: public testing::Test
{
public:
    MockListener getSpecialListener()
    {
        MockListener special;
        EXPECT_CALL(special, /** Some special behaviour e.g. WillRepeatedly(Invoke( */ );
        return special;
    }
};

TEST_F(MyTest, MyTestUsingSpecialListener)
{
    MockListener special = getSpecialListener();

    // Do something with special.
}

Unfortunately I get:

error: use of deleted function ‘MockListener ::MockListener (MockListener &&)’

So I assume mocks can't be copied? Why, and if so is there another elegant way to get a function to manufacture a ready-made mock with expectations/actions already set?

Obviously I can make the getSpecialListener return a MockListener&, but then it would unnecessarily need to be a member of MyTest, and since only some of the tests use that particular mock (and I should only populate the mock behaviour if the test is using it) it would be less clean.

Answer 1

Mock objects are non-copyable, but you can write a factory method that returns a pointer to a newly created mock object. To simplify the object ownership, you can use std::unique_ptr.

std::unique_ptr<MockListener> getSpecialListener() {
  MockListener* special = new MockListener();
  EXPECT_CALL(*special, SomeMethod()).WillRepeatedly(DoStuff());
  return std::unique_ptr<MockListener>(special);
}

TEST_F(MyTest, MyTestUsingSpecialListener) {
  std::unique_ptr<MockListener> special = getSpecialListener();

  // Do something with *special.
}