A federated society of bots for smart contract testing

Smart contracts are a new type of software that allows its users to perform irreversible transactions on a distributed persistent data storage called the blockchain. The nature of such contracts and the technical details of the blockchain architecture give raise to new kinds of faults, which require specific test behaviours to be exposed. In this paper we present SoCRATES, a generic and extensible framework to test smart contracts running in a blockchain. The key properties of SoCRATES are: (1) it comprises bots that interact with the blockchain according to a set of composable behaviours; (2) it can instantiate a society of bots, which can trigger faults due to multi-user interactions that are impossible to expose with a single bot. Our experimental results show that SoCRATES can expose known faults and detect previously unknown faults in contracts currently published in the Ethereum blockchain. They also show that a society of bots is often more effective than a single bot in fault exposure. (C) 2020 Elsevier Inc. All rights reserved.