Exploring API Behaviours Through Generated Examples

TL;DR

This paper introduces a novel method for automatically generating relevant API behaviour examples without needing source code or formal specifications, aiding engineers in understanding third-party APIs.

Contribution

It presents a new approach to generate API examples in black-box scenarios, expanding capabilities beyond existing white-box or formal specification-based methods.

Findings

Produces small, relevant API examples

Helps engineers understand third-party APIs

Effective on industry-grade REST APIs

Abstract

Understanding the behaviour of a system's API can be hard. Giving users access to relevant examples of how an API behaves has been shown to make this easier for them. In addition, such examples can be used to verify expected behaviour or identify unwanted behaviours. Methods for automatically generating examples have existed for a long time. However, state-of-the-art methods rely on either white-box information, such as source code, or on formal specifications of the system behaviour. But what if you do not have access to either? e.g., when interacting with a third-party API. In this paper, we present an approach to automatically generate relevant examples of behaviours of an API, without requiring either source code or a formal specification of behaviour. Evaluation on an industry-grade REST API shows that our method can produce small and relevant examples that can help engineers to understand the system under exploration.