GraphQL Tools
Build, mock, and stitch a GraphQL schema using the schema language
...Use the GraphQL schema definition language to generate a schema with full support for resolvers, interfaces, unions, and custom scalars. With GraphQL Tools, you can mock your GraphQL API with fine-grained per-type mocking for fast prototyping without any data sources. Automatically stitch multiple schemas together into one larger API in a simple, fast and powerful way. You can develop your JavaScript-based GraphQL API with graphql-tools and GraphQL Yoga together: One to write the schema and resolver code, and the other to connect it to a web server. When using graphql-tools, you describe the schema as a GraphQL-type language string.