@graphql-tools/schema

What is @graphql-tools/schema?

The @graphql-tools/schema package is a utility library that helps with the creation and manipulation of GraphQL schemas. It provides functions to make it easier to work with GraphQL schema definitions, including merging type definitions, adding resolvers, and more.

What are @graphql-tools/schema's main functionalities?

makeExecutableSchema

This feature allows you to combine type definitions and resolvers to create an executable GraphQL schema.

const { makeExecutableSchema } = require('@graphql-tools/schema');
const typeDefs = `
  type Query {
    hello: String
  }
`;
const resolvers = {
  Query: {
    hello: () => 'Hello world!',
  },
};
const schema = makeExecutableSchema({
  typeDefs,
  resolvers,
});

addResolversToSchema

This feature enables you to add new resolvers to an existing GraphQL schema.

const { addResolversToSchema } = require('@graphql-tools/schema');
const schema = makeExecutableSchema({ typeDefs });
const resolvers = {
  Query: {
    hello: () => 'Hello world!',
  },
};
addResolversToSchema({ schema, resolvers });

addSchemaLevelResolver

This feature allows you to add a resolver function that runs before any other resolvers for each operation.

const { addSchemaLevelResolver } = require('@graphql-tools/schema');
const schema = makeExecutableSchema({ typeDefs, resolvers });
const rootResolver = (root, args, context, info) => { /*...*/ };
addSchemaLevelResolver(schema, rootResolver);

Other packages similar to @graphql-tools/schema

graphql-tools

This is a more comprehensive package that includes @graphql-tools/schema as a part of its toolkit. It provides additional utilities for mocking and stitching GraphQL schemas.

apollo-server

While not a direct alternative, Apollo Server uses similar concepts and includes the ability to create an executable schema. It is a full-featured GraphQL server that integrates well with @graphql-tools/schema.

merge-graphql-schemas

This package provides functionality to merge GraphQL type definitions and resolvers. It is similar to some of the features in @graphql-tools/schema but is more focused on the merging aspect.

README

Check API Reference for more information about this package; https://www.graphql-tools.com/docs/api/modules/schema_src

You can also learn more about Generating Executable Schemas in this chapter; https://www.graphql-tools.com/docs/generate-schema