Schema-based GraphQL server design

Explore src/schema/ to see how the files are organized.

About this design

This design adheres to 3 guidelines:

1. The server should be modularized by type.

2. Each type and field is a module and should:

   • be represented by a directory or file with the same name as the type or field

   • expose a default export which implements the following standard interface:

     interface GraphQLModule {
       typeDefs: DocumentNode | RecursiveArray<DocumentNode>;
       resolvers?: Resolvers | RecursiveArray<Resolvers>;
     }

     Note: If inheritResolversFromInterfaces is enabled, only custom fields need their own resolvers and typeDefs.

3. A type directory can be nested within another type directory as long as it isn’t used outside of the directory in which it’s nested. If a type is used only within a single field, that field’s file can be turned into a directory which contains the type directory and an index file which exports the field resolver and typeDefs.

The result of these guidelines is a GraphQL server structured in roughly the same way as the schema it generates, with some convenient nesting where possible. I recommend using this server design alongside a type generation solution (such as GraphQL Code Generator) and makeExecutableSchema (with inheritResolversFromInterfaces: true).

This design can be applied flexibly in most any GraphQL server project, federated or not.

Instructions

To generate types:

npm run generate

To generate types and print the schema in the terminal:

npm run generate:print

To compile the app:

npm run build

To run the server:

1. Execute dev script

   npm run dev
   

2. Navigate to http://localhost:4000

3. Click "Query your server"

4. Explore the schema and run queries