$ show webonyx/graphql-php
webonyx/graphql-php is a comprehensive PHP implementation of the GraphQL specification, serving as a server-side library for parsing, validating, and executing GraphQL queries. It provides a full type system (ObjectType, InterfaceType, UnionType, EnumType, InputObjectType, ScalarType), a recursive-descent parser, an AST visitor infrastructure, a query validator with over 30 validation rules, and a reference executor that mirrors the GraphQL.js implementation. The library also includes a PSR-7-compatible server layer (StandardServer) for handling HTTP requests, along with optional promise adapters for async execution via ReactPHP or Amp. The architecture is library-oriented: clients build schemas programmatically or from SDL via BuildSchema, then execute queries through GraphQL::executeQuery() or the StandardServer. The type system uses lazy initialization (closures/callables) to handle circular references, and a type loader enables deferred schema composition. Notable design patterns include a rich AST visitor with enter/leave operations (including skip, stop, remove, edit), a synchronous promise adapter that enables DataLoader-like batching in synchronous PHP, and a modular validation rule system where each rule is a standalone visitor. The codebase demonstrates high craftsmanship with heavy use of static analysis (PHPStan), extensive unit tests ported from graphql-js, and performance benchmarks. While it is a port of the JavaScript reference implementation, it introduces PHP-idiomatic features such as attribute-based annotations (#[Description], #[Deprecated]) and per-schema scalar overrides.
The LLM identified 3 files worth highlighting for reuse:
A lightweight, reusable key-value store that supports any key type (scalar, object, array) by internally using both an array for scalar keys and SplObjectStorage for object keys. It can be extracted and used in any PHP project requiring a flexible storage mechanism with predictable iteration order. Demonstrates non-obvious use of SplObjectStorage combined with arrays.
Computes a modified Damerau-Levenshtein distance for generating typo suggestions for user-facing error messages. The implementation is optimized for GraphQL keyword matching (case-insensitive start, limited distance), but can be extracted as a general-purpose suggestion list generator. It is fully self-contained and depends only on PHP arrays and strings.
A robust visitor implementation for GraphQL AST traversal that supports enter/leave callbacks, parallel visitors (visitInParallel), type-info integration (visitWithTypeInfo), and fine-grained operations (skip node, stop traversal, remove node, edit node). The pattern is generic enough to be extracted for any tree-like data structure with node kinds. It demonstrates advanced PHP usage with closures and dynamic method calls.