I've always been dubious of using mock for tests which involve external API calls; at best they require you to reimplement the API according to the documentation (which there may be none, or that the API doesn't follow exactly for edge cases (i.e. the things you're meant to be testing)). At worst you're implementing a very small subset of the behaviour of the API and not testing how your code responds to the other behaviour. But I haven't come across other solutions (not that I have that a heap of experience here, just contributions to a couple of oss projects).