I would like to know how others have solved the Problem of Unit Testing an app that uses the Dropbox API without going on the network. I am using the swift, .net and PHP sdk's.
Can I run a local Dropbox server and get the API's to use that endpoint?
You should be swapping out the Dropbox parts for mocks, which return ideal responses - you shouldnt ever test more code than absolutely necessary in a unit test, and that includes third party libraries or integrations.
If the Dropbox part fails, thats an entirely different ball game, but you should be assuming the response your unit tests requires, which means successes and failures as you test those parts of your code.