Square retrofit server mock for testing

Question

What's the best way to mock a server for testing when using the square retrofit framework.

Potential ways:

1. Create a new retrofit client and set it in the RestAdapter.Builder().setClient(). This involves parsing the Request object and returning the json as a Response object.

2. Implement this annotated interface as a mock class and use that in place of the version provided by RestAdapter.create() (wont test gson serialisation)

3. ?

Ideally I want to have the mocked server provide json responses so I can test the gson serialisation at the same time.

Any examples would be greatly appreciated.

Answer 1

I decided to try method 1 as follows

public class MockClient implements Client {

    @Override
    public Response execute(Request request) throws IOException {
        Uri uri = Uri.parse(request.getUrl());

        Log.d("MOCK SERVER", "fetching uri: " + uri.toString());

        String responseString = "";

        if(uri.getPath().equals("/path/of/interest")) {
            responseString = "JSON STRING HERE";
        } else {
            responseString = "OTHER JSON RESPONSE STRING";
        }

        return new Response(request.getUrl(), 200, "nothing", Collections.EMPTY_LIST, new TypedByteArray("application/json", responseString.getBytes()));
    }
}

And using it by:

RestAdapter.Builder builder = new RestAdapter.Builder();
builder.setClient(new MockClient());

It works well and allows you to test your json strings without having to contact the real server!