Extensible Testing for Infrastructure as Code

Developers automate deployments with Programming Languages Infrastructure as Code (PL-IaC) by implementing IaC programs in popular languages like TypeScript and Python. Yet, systematic testing-well established for high-velocity software development-is rarely applied to IaC programs because IaC testing techniques are either slow or require extensive development e ort. To solve this dilemma, we develop ProTI, a novel IaC unit testing approach, and implement it for Pulumi TypeScript. Our preliminary experiments with simple type-based test case generators and oracles show that ProTI can nd bugs reliably in a short time, often without writing any additional testing code. ProTI's extensible plugin architecture allows combining, adopting, and experimenting with new approaches, opening the discussion about novel generators and oracles for e cient IaC testing.