A Framework for Automated Test Mocking of Mobile Apps

Mobile apps interact with their environment extensively, and these interactions can complicate testing activities because test cases may need a complete environment to be executed. Interactions with the environment can also introduce test flakiness, for instance when the environment behaves in non-deterministic ways. For these reasons, it is common to create test mocks that can eliminate the need for (part of) the environment to be present during testing. Manual mock creation, however, can be extremely time consuming and error-prone. Moreover, the generated mocks can typically only be used in the context of the specific tests for which they were created. To address these issues, we propose MOKA, a general framework for collecting and generating reusable test mocks in an automated way. MOKA leverages the ability to observe a large number of interactions between an application and its environment and uses an iterative approach to generate two possible, alternative types of mocks with different reusability characteristics: advanced mocks generated through program synthesis (ideally) and basic record-replay-based mocks (as a fallback solution). In this paper, we describe the new ideas behind MOKA, its main characteristics, a preliminary empirical study, and a set of possible applications that could benefit from our framework.