graphile-utils

This package contains helpers for building plugins for GraphQL schemas utilising Graphile Engine, such as the one produced by PostGraphile.

Documentation is currently available here.

PRs to improve documentation are always welcome!

gql

Similar to the default export from graphql-tag, this export can be used to form tagged template literals that are useful when building schema extensions. gql in graphile-utils differs from graphql-tag in a number of ways, most notably: it can use interpolation to generate dynamically named fields and types, and it can embed raw values using the embed helper.

embed

Used to wrap a value to be included in a gql AST, e.g. for use in GraphQL directives.

makeExtendPluginSchema

Enables you to add additonal types or extend existing types within your Graphile Engine GraphQL schema.

const {
  makeExtendSchemaPlugin,
  gql,
} = require('graphile-utils');

const MySchemaExtensionPlugin =
  makeExtendSchemaPlugin(
    build => ({
      typeDefs: gql`...`,
      resolvers: ...
    })
  );

module.exports = MySchemaExtensionPlugin;

e.g.:

makeExtendSchemaPlugin(build => ({
  typeDefs: gql`
    type Random {
      float: Float!
      number(min: Int!, max: Int!): Int!
    }
    extend type Query {
      random: Random
    }
  `,
  resolvers: {
    Query: {
      random() {
        return {};
      },
    },
    Random: {
      float() {
        return Math.random();
      },
      number(_parent, { min, max }) {
        return min + Math.floor(Math.random() * (max - min + 1));
      },
    },
  },
}));

makeAddInflectorsPlugin

If you don't like the default naming conventions that come with a Graphile Engine GraphQL schema then it's easy for you to override them using the inflector.

For example, if you want '*Patch' types to instead be called '*ChangeSet' you could make a plugin such as this one:

const { makeAddInflectorsPlugin } = require('graphile-utils');

module.exports = makeAddInflectorsPlugin({
  patchType(typeName: string) {
    return this.upperCamelCase(`${typeName}-change-set`);
  },
});

The default Graphile Engine inflectors (pluralize, singularize, upperCamelCase, camelCase and constantCase) can be found here.

The additional inflectors used in PostGraphile can be found here.