Supporting Round-Trip Data Migration for Web APIs: A Henshin Solution

We present a solution to the Round-Trip Migration case of the Transformation Tool Contest 2020, based on the Henshin model transformation language. The task is to support four scenarios of transformations between two versions of the same data metamodel, a problem inspired by the application scenario of Web API migration, where such a round-trip migration methodology might mitigate drawbacks of the conventional "instant" migration style. Our solution relies on Henshin's visual syntax, which seems well-suited to capture the problem on an intuitive level, since the syntax is already similar to the scenario illustrations in the case description. We discuss the five evaluation criteria expressiveness, comprehensibility, bidirectionality, performance, and reusability.