@graphql-tools/merge

What is @graphql-tools/merge?

The @graphql-tools/merge package is designed to provide a set of utilities for merging GraphQL schemas and type definitions. It is part of the larger GraphQL Tools library, which offers a variety of tools for working with GraphQL schemas, including stitching, mocking, and more. The merge package specifically focuses on combining multiple GraphQL type definitions and schemas into a single schema, which is particularly useful in modularized codebases where schema definitions may be spread across multiple files or modules.

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

Merging GraphQL Type Definitions

This feature allows for the merging of GraphQL type definitions from multiple sources. It's useful for modularizing your GraphQL schema definitions.

const { mergeTypeDefs } = require('@graphql-tools/merge');
const typeDefs1 = `type Query { foo: String }`;
const typeDefs2 = `type Query { bar: Int }`;
const mergedTypeDefs = mergeTypeDefs([typeDefs1, typeDefs2]);

Merging GraphQL Schemas

This feature enables the merging of multiple GraphQL schemas into a single schema. It is particularly useful for combining schemas from different parts of an application or different services.

const { makeExecutableSchema } = require('@graphql-tools/schema');
const { mergeSchemas } = require('@graphql-tools/merge');
const schema1 = makeExecutableSchema({ typeDefs: `type Query { foo: String }` });
const schema2 = makeExecutableSchema({ typeDefs: `type Query { bar: Int }` });
const mergedSchema = mergeSchemas({ schemas: [schema1, schema2] });

Other packages similar to @graphql-tools/merge

graphql-tools

This is a more comprehensive suite of tools that includes @graphql-tools/merge as part of its functionality. It offers additional utilities for working with GraphQL, such as schema stitching, mocking, and more. Compared to @graphql-tools/merge, it provides a broader range of GraphQL utilities beyond just merging.

graphql-compose

This package provides a way to construct GraphQL schema with an object-oriented approach. It includes functionality for merging types, which is similar to what @graphql-tools/merge offers. However, graphql-compose goes beyond just merging, offering a rich set of tools for schema construction, modification, and querying.

README

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

You can also learn more about Schema Merging in this chapter; https://www.graphql-tools.com/docs/schema-merging