A Model-Driven Method for Fast Building Consistent Web Services from OpenAPI-Compatible Models

Lots of software companies rely on web technologies to test market hypotheses in order to develop viable businesses. They often need to quickly build web services that are at the core of their Minimum Viable Products (MVPs). MVPs must be reliable whereas they are based on specifications and hypotheses that are likely to change. Web services need to be well documented, to make it easy to develop applications that consume them. Model Driven Engineering approaches have been proposed and used to develop and evolve web services on one hand, and document them on the other hand. However, these approaches lack the ability to be suitable for both (i) rapid prototyping, (ii) model verification, (iii) compatibility with common programming languages and (iv) alignment between documentation and implementation. Here we propose a meta-model to express web services, the related tool to verify models consistency and an integration of this approach into the OpenAPI Specification. We adopt a shallow verification process to allow rapid prototyping by developers who are not formal methods experts, while still offering design-time guarantees that improve product quality and development efficiency. Web services are defined using parametric components which enable to express and formally verify web service patterns and to safely reuse them in other contexts. We built a tool to check consistency of extended OpenAPI 3.0 models and associated components implementations in order to generate corresponding web services. This allows us to give flexibility and verification support to developers, even in the context of an incremental development, as illustrated by a case study.