A Mechanized Formalization of GraphQL

Tomás Díaz (1) , Federico Olmedo (2, 1) , Éric Tanter (2, 1, 3)

1 IMFD Chile - Instituto Milenio Fundamentos de los Datos
2 DCC - Computer Science Department [Santiago]
3 PROSECCO - Programming securely with cryptography

GraphQL is a novel language for specifying and querying web APIs, allowing clients to flexibly and efficiently retrieve data of interest. The GraphQL language specification is unfortunately only available in prose, making it hard to develop robust formal results for this language. Recently, Har-tig and Pérez proposed a formal semantics for GraphQL in order to study the complexity of GraphQL queries. The semantics is however not mechanized and leaves certain key aspects unverified. We present GraphCoQL, the first mechanized formalization of GraphQL, developed in the Coq proof assistant. GraphCoQL covers the schema definition DSL, query definitions, validation of both schema and queries, as well as the semantics of queries over a graph data model. We illustrate the application of GraphCoQL by formalizing the key query transformation and interpretation techniques of Hartig and Pérez, and proving them correct, after addressing some imprecisions and minor issues. We hope that GraphCoQL can serve as a solid formal baseline for both language design and verification efforts for GraphQL.

Mots clés: Coq; Mechanized metatheory; GraphQL; Query languages

Domaines: Langage de programmation [cs.PL]

Tomás Díaz, Federico Olmedo, Éric Tanter. A Mechanized Formalization of GraphQL. CPP 2020 - 9th ACM SIGPLAN International Conference on Certified Programs and Proofs, Jan 2020, New Orleans, United States. ⟨10.1145/3372885.3373822⟩. ⟨hal-02422532⟩