Indeed, plus using a mock adds a whole new class of bugs, arising from the mock not precisely mimicking the real component or subsystem. As the sorts of bugs yo

Indeed, plus using a mock adds a whole new class of bugs, arising from the mock not precisely mimicking the real component or subsystem. As the sorts of bugs you are trying flush out in integration testing generally result from unforeseen interactions between components, it is more likely than chance that the mock will not behave in a way that will reveal the presence of the error.