`graphql-typed-document-node`

This repository is the home for graphql-typed-document-node and integration related to it.

graphql-typed-document-node is a development tool for creating fully typed DocumentNode objects. It means that just by passing the GraphQL query/mutation/subscription/fragment to a supporting GraphQL client library, you'll get a fully type result object and variables object.

It made possible by TypeScript type inference.

This project works in the following way:

Configure your project to use this library (see How to use? below).
Write your GraphQL operations (query / mutation / subscription / fragment).
GraphQL Code Generator will generate a TypedDocumentNode for your operations (which is a bundle of pre-compiled DocumentNode with the operation result type and variables type).
You'll get automatic type inference, auto-complete and type checking based on your GraphQL operation.

Supported Libraries

As of 2022, most GraphQL Client libraries supports TypedDocumentNode out of the box.

The following patches are currently supported:

Built-in support

@apollo/client (v4 and also, >=3.2.0, if you are using React Components (<Query>) you still need a patch)
apollo-angular (since 2.6.0)
@urql/core (since 1.15.0)
@urql/preact (since 1.4.0)
urql (since 1.11.0)
@urql/exchange-graphcache (since 3.1.11)
@urql/svelte (since 1.1.3)
villus (since 1.0.0-beta.8)
graphql-js (since 15.2.0)
@vue/apollo-composable (since 4.0.0-alpha.13)
graphql-request (since 5.0.0)
graphql-js (since v16)

How to use?

‼️ In most cases, you should not deal with TypedDocumentNode directly, but use a library that supports it under the hood.

We recommend to use GraphQL Codegen with client-preset for the ideal setup. You can follow the guides section in GraphQL-Codegen website

Utils

The core package of typed-document-node exports 3 types only:

TypedDocumentNode - the base of this library.
ResultOf - a utils for extracting the result type from an existing TypeDocumentNode instance (ResultOf<typeof MyQueryDocument>)
VariablesOf - a utils for extracting the variables type from an existing TypeDocumentNode instance (VariablesOf<typeof MyQueryDocument>)

How can I support this in my library?

If you are a library maintainer, and you wish to have built-in TS support in your library, you can add support for TypedDocumentNode without having any breaking changes to your API.

Basically, in any place where you need to have typed access to the result type of an operation, or to a typed variables object, make sure to have generics for both types, and use TypeDocumentNode in your arguments, instead of DocumentNode. This will allow TypeScript to infer the types based on the object you are passing to it later.

Before

type GqlFetchResult = {
  data?: any;
  errors?: Error[];
};

export function gqlFetch(
  operation: DocumentNode,
  variables?: Record<string, any>
): GqlFetchResult {
  // ...
}

After

import { TypedDocumentNode } from "@graphql-typed-document-node/core";

type GqlFetchResult<TData = any> = {
  data?: TData;
  errors?: Error[];
};

export function gqlFetch<TData = any, TVariables = Record<string, any>>(
  operation: TypedDocumentNode<TData, TVariables>,
  variables?: TVariables
): GqlFetchResult<TData>;
export function gqlFetch<TData = any, TVariables = Record<string, any>>(
  operation: DocumentNode,
  variables?: TVariables
): GqlFetchResult<TData> {
  // ...
}

Thanks & Inspiration

https://github.com/dotansimha/graphql-code-generator/issues/1777#issue-437813742 for the concept of generating unified clients support
https://github.com/Shopify/quilt/blob/main/packages/graphql-typed/src/index.ts for similar idea

dotansimha / graphql-typed-document-node

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