Generating SDL

Warning This chapter applies only to the code first approach.

To manually generate a GraphQL SDL schema (i.e., without running an application, connecting to the database, hooking up resolvers, etc.), use the GraphQLSchemaBuilderModule.

async function generateSchema() {
  const app = await NestFactory.create(GraphQLSchemaBuilderModule);
  await app.init();
  const gqlSchemaFactory = app.get(GraphQLSchemaFactory);
  const schema = await gqlSchemaFactory.create([RecipesResolver]);
  console.log(printSchema(schema));
}

Hint The GraphQLSchemaBuilderModule and GraphQLSchemaFactory are imported from the @nestjs/graphql package. The printSchema function is imported from the graphql package.

Usage

The gqlSchemaFactory.create() method takes an array of resolver class references. For example:

const schema = await gqlSchemaFactory.create([
  RecipesResolver,
  AuthorsResolver,
  PostsResolvers,
]);

It also takes a second optional argument with an array of scalar classes:

const schema = await gqlSchemaFactory.create(
  [RecipesResolver, AuthorsResolver, PostsResolvers],
  [DurationScalar, DateScalar],
);

Lastly, you can pass an options object:

const schema = await gqlSchemaFactory.create([RecipesResolver], {
  skipCheck: true,
  orphanedTypes: [],
});

• skipCheck: ignore schema validation; boolean, defaults to false
• orphanedTypes: list of classes that are not explicitly referenced (not part of the object graph) to be generated. Normally, if a class is declared but isn’t otherwise referenced in the graph, it’s omitted. The property value is an array of class references.