How to change the type of an assigned object with Google Mock?

Question

I want to check the behaviour of a method by testing a protected variable of an assigned object. Therefore, I want to inject a mock object for this assigned object. My problem is that this object is created during this method and is not given trough a parameter.

bool MappingConfigurationBuilder::buildMappingConfiguration(MappingConfiguration*& mappingConfiguration)
{
  ...
  ConfigurationForColor configurationForColor;
  buildConfigurationForColor(configurationForColor);
  mappingConfiguration = new MappingConfiguration(configurationForHeight, configurationForColor);
  ...
  return true;
}

This method should create a ConfigurationForColor, change a protected variable on it in the protected method buildConfigurationForColor(...) and assign the object to a MappingConfiguration. I want to check the protected variable on configurationForColor.

Can I use Google Mock to change the type of configurationForColor to a mock object? Or is their another possibility to test the protected variable?

Answer 1

It sounds like you need some kind of inversion of control.

For that, it would be good to create a factory, which returns MappingConfiguration type objects (either mocks or real objects).