$ show urql-graphql/urql
urql is a highly customizable and versatile GraphQL client library for JavaScript/TypeScript, organized as a monorepo with a core package (`@urql/core`), multiple exchange packages (middleware), and framework-specific bindings for React, Preact, Vue, Svelte, Solid, and Next.js. The core architecture is built on a composable exchange pipeline using Wonka reactive streams, where operations flow through a chain of exchanges (e.g., cache, fetch, subscription, SSR) that can be mixed and matched. The client dispatches GraphQL queries, mutations, and subscriptions, and returns results as streams. The `@urql/exchange-graphcache` package provides a sophisticated normalized cache with support for offline persistence, optimistic updates, pagination resolvers (Relay and simple), and schema-aware partial results. Framework integrations expose idiomatic hooks (e.g., `useQuery`, `useMutation`) or stores that wrap the core client and manage component lifecycle. External dependencies include Wonka for streams, `@0no-co/graphql.web` for GraphQL parsing, and framework-specific libraries. The repository also includes a documentation site, extensive examples, and a comprehensive test suite using Vitest and Cypress.
The LLM identified 5 files worth highlighting for reuse:
A reusable resolver factory for Relay-style cursor-based pagination. It handles merging pages with configurable merge modes (inwards/outwards), deduplication of edges, and orphan page management. It can be used with any Graphcache normalized cache instance and requires only a schema with standard Relay connection types. Demonstrates non-obvious skill in handling edge cases like duplicate edges and page ordering.
A default storage adapter implementation for Graphcache's offline persistence, using IndexedDB. It implements the `StorageAdapter` interface with methods for reading/writing data and metadata, and online status detection. Self-contained and can be replaced by custom adapters (e.g., React Native AsyncStorage). Demonstrates a clean separation of concerns for offline caching.
A utility that minifies an introspection query result by removing scalars, enums, input types, and other non-essential schema information, reducing the payload size for Graphcache schema awareness. It is a pure function with no dependencies on the rest of urql, making it easily extractable for any project needing to shrink introspection data.
A utility that transforms a GraphQL document by automatically adding `__typename` fields to selection sets where missing, and processing client-side directives like `@_optional` and `@_required`. It is a standalone function that can be reused in any GraphQL client or tooling to ensure type information is present for caching or normalization.
A unified error class (`CombinedError`) that wraps both network errors and GraphQL errors into a single object with a consistent API. It provides methods to extract error messages, distinguish error types, and serialize/deserialize. This pattern is reusable in any GraphQL client or API client that needs to handle multiple error sources uniformly.