Writing Android acceptance tests with robolectric:

Can Android acceptance tests be written using Robolectric? It seems to be classed only as a unit-testing framework.

Why can it not be classed as acceptance or "end-to-end" testing framework? (Can it be adapted for that purpose?)

I think this may be a bit subjective, but I feel it's answerable, so here's my take on it.

Is it an e2e testing framework?

It cannot be "end-to-end" because the application doesn't actually run on a device, the dependencies may be mocked out, network is usually mocked out and the tests don't simulate exactly how a user would work with the app. The lifecycle is simulated and controlled by you in the tests. It doesn't even run on the dalvik-VM and there are difference between dalvik and the JVM (here's a simple but relevant example: British Summer Time - BST not recognised by SimpleDateFormat timezone)

For me, an end-to-end test can only be achieved with a deployed application, using the network, connecting to the server it needs to, getting the information, showing it correctly on screen and the test verifying what can be seen on screen. Again, this may be subjective, but that's what e2e means to me.

Can it be used to write acceptance tests?

That depends on what you want from your acceptance tests, as I've seen people use this term differently, but I would say the answer is a definite yes. We use robolectric to test most of our business logic as we have found UI tests to not be reliable.

You can instantiate your UI elements with the right data, interact with UI elements, check what they show on screen. I would say this covers a lot of ground.

That said, sometimes these tests were very difficult to write, and we got a lot out of architecting our code differently (Model-View-Presenter is most commonly suggested for that) The key for us was to have pretty "dumb" views and to let the presenter determine what will be shown on screen. Then you test that presenter heavily with robolectric tests and you can definitely write tests of the type "given this series of inputs, I expect to see these outputs on screen". Testing the view further adds little value because it's just a shell for what your presenter serves it.

I think describing how to apply MVP to your project is outside the scope of a SO answer, but I hope this helps.