Declarative smart contract testing by domain experts

We present a novel approach to testing Answer Set Programs (ASPs) in the context of a system designed to enable a domain expert to write, test and deploy legal smart contracts. Common practice is to use compiled imperative languages to write smart contracts which limits what can be achieved, and provides a clear opportunity for an approach that empowers domain experts. Our system supports the construction of declarative smart contracts by domain experts with the help of a smart user interface that communicates visually and verbally using domain expert level concepts. It captures the ontology and legal logic of a legal document in a model automatically constructed as an ASP program. This paper discusses a complementary approach to testing, achieved by structuring ASP rules and splitting testing into model validation and program verification. Holding ontology information about the application domain allows the approach to be highly automated, so that we achieve automatic discovery of all hypothetical scenarios and exhaustive testing for each rule. Our approach places the domain expert in a tight learning loop where the behaviour of each rule scenario can be understood from the visual and verbal feedback, and rule corrections can be made immediately as required.