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Version: Next (2.x)

Scalars

Baeta provides support for custom GraphQL scalars, allowing you to define any data type beyond the built-in primitives.

Schema Definition​

Define your scalars in a GraphQL schema file, for example src/modules/scalars/scalars.gql:

scalar DateTime
scalar UUID

Implementation​

Register the scalar resolvers in your module using graphql-scalars or your own implementation:

// src/modules/scalars/index.ts
import { DateTimeResolver, UUIDResolver } from "graphql-scalars";
import { ScalarsModule } from "./typedef.ts";

export default ScalarsModule.$schema({
  DateTime: DateTimeResolver,
  UUID: UUIDResolver,
});

Custom TypeScript Types​

To map a scalar to a custom TypeScript type, add it to the Scalars interface in src/modules/types.ts:

export interface Scalars extends BaseScalars {
  UUID: `${string}-${string}-${string}-${string}-${string}`;
  DateTime: Date;
}

For more details on the types file, see Custom Types.

tip

If you don't add a custom type mapping, the scalar will default to any. Adding entries to the Scalars interface ensures full type safety in resolvers.

Usage in Resolvers​

The scalars are automatically typed in your resolvers:

const { Query, User } = UserModule;

const userQuery = Query.user.resolve(() => {
  return {
    id: randomUUID(), // typed as UUID
    email: "[email protected]",
    birthday: new Date("1990-01-01"), // typed as Date
  };
});

Built-in Scalars​

GraphQL includes several built-in scalar types that don't require any additional configuration:

  • Int
  • Float
  • String
  • Boolean
  • ID