isabella232 / graphql-introfields

GraphQL resolver utilities based on fields introspection.

GraphQL Introfields

🏑 GraphQL resolver utilities based on fields introspection.
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Table of Contents

• Table of Contents
• About The Project
  • Built With
• Getting Started
  • Installation
  • Usage
    • Basic Example
    • resolveIDFieldFromRoot
• Roadmap
• Contributing
• License
• Contact
• Acknowledgements

About The Project

This library provides utilities to facilitate the resolution of GraphQL based on which fields are requested.

Built With

• Typescript
• GraphQL
• Jest

Getting Started

Installation

npm install graphql-introfields

Usage

Basic Example

With the following schema:

type Employee {
  id: ID!
  name: String!
}

type VideoStore {
  id: ID!
  employees: [Employee!]!
  manager: Employee!
}

type Query {
  videostore: VideoStore
}

schema {
  query: Query
}

And with the following resolvers:

import { resolveBasedOnFields } from 'graphql-introfields';

const resolvers = {
  Query: {
    videostore: getVideoStoreData,
  },
  VideoStore: {
    manager: resolveBasedOnFields((fields) => {
      // if you know that only the `id` field is asked for, and it's present on the root, you can prevent
      // unnecessary resolution of the manager field (which may be an over-the-network request).
      if (fields.length === 1 && fields[0].name.value === 'id') {
        return (root, _args, _ctx, _info) => ({ id: root['managerId'] });
      }
      return (root, _args, _ctx, _info) => getEmployeeById(root.managerId);
    }),
  },
}

The following query doesn't actually call getEmployeeById:

query {
  videostore {
    manager {
      id
    }
  }
}

resolveIDFieldFromRoot

The above use-case is actually available as a provided utility.

import { resolveIDFieldFromRoot } from 'graphql-introfields';
const resolvers = {
  videostore: {
    manager: resolveIDFieldFromRoot(
      'managerId',
      (root) => getEmployeeById(root.managerId)
    )
  }
}

Roadmap

See the open issues for a list of proposed features (and known issues).

Contributing

Contributions are what make the open source community such an amazing place to be learn, inspire, and create. Any contributions you make are greatly appreciated.

1. Fork the Project
2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
3. Commit your Changes (git commit -m 'Add some AmazingFeature')
4. Push to the Branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

License

Distributed under the MIT License. See LICENSE for more information.

Contact

Maintainer: Joel Marcotte (Github @joual)

Project Link: https://github.com/SurveyMonkey/graphql-introfields

Acknowledgements

• GraphQL-Tools
• GraphQL-JS