Consumer-Driven Contract Tests for Microservices: A Case Study

Design by contract is a paradigm that aims at capturing the interactions of different software components, and formalizing them so that they can be relied upon in other phases of the design. Such a characteristic is especially helpful in the context of microservice architecture, where each service is an independent entity that can be individually (re)deployed. With contracts, testing of microservice based systems can be improved so that also the integration of different microservices can be tested in isolation by the developers working on the system. In this paper, we study how systems based on microservice architecture and their integrations can be tested more effectively by extending the testing approach with consumer-driven contract tests. Furthermore, we study how the responsibilities and purposes of each testing method are affected when introducing the consumer-driven contract tests to the system.