FieldBuilder

The field builder is the t passed to a fields callback. See Fields for examples. The option types below summarize an API whose concrete types are inferred from your schema.

field(options)

• options: FieldOptions

FieldOptions

type FieldOptions = {
  type: ReturnType;
  args?: Args;
  nullable?: boolean | { list: boolean; items: boolean };
  description?: string;
  deprecationReason?: string;
  resolve: (parent, args, context, info) => ResolveValue;
  extensions?: Readonly<Record<string, unknown>>;
};

• type: Type Parameter
• args: a map of argument names to refs, created with t.arg or builder.args.
• nullable: defaults to true, unless overwritten in SchemaBuilder see Changing Default Nullability.
• description: string
• deprecationReason: string
• resolve: Resolver

Type Parameter

A Type Parameter for a Field can be any TypeRef returned by one of the SchemaBuilder methods for defining a type, a class used to create an object or interface type, a ts enum used to define a graphql enum type, or a string that corresponds to one of the keys of the Objects, Interfaces, or Scalars objects defined in SchemaTypes.

For list fields, wrap the type in an array, for example ['User']. A boolean nullable controls the list itself; items are non-null by default. Use { list: true, items: true } to allow both a null list and null items.

Resolver

A function to resolve the value of this field.

Return type

Field resolvers should return a value (or promise) that matches the expected type for this field. For scalars, this is their output shape. For objects and interfaces, it is the backing shape carried by a ref, class, or SchemaTypes entry. For Unions, the type may be any of the corresponding shapes of members of the union. For Enums, the value is dependent on the implementation of the enum. See the Enums guide for more details.

Args

• parent: the backing value of the current type. Root fields receive the root value, typed by SchemaTypes.Root.

• args: an object matching the shape of the args option for the current field

• context: The Context type defined in SchemaTypes.

• info: a GraphQLResolveInfo object see

  https://graphql.org/graphql-js/type/#graphqlobjecttype

  for more details.

helpers

A set of helpers for creating scalar fields. These work the same as field, but omit the type field from options.

Scalars

• string(options)
• id(options)
• boolean(options)
• int(options)
• float(options)
• stringList(options)
• idList(options)
• booleanList(options)
• intList(options)
• floatList(options)

listRef(type, options?)

Creates a list type reference, including nested lists. options.nullable controls the items and defaults to false; the field options control the outer list.

expose

A set of helpers to expose fields from the backing model. The name arg can be any field from the backing model that matches the type being exposed. Options are the same as field, but type, resolve, and args are omitted.

The general expose(name, { type, ...options }) helper also supports object, enum, and custom scalar properties.

• exposeString(name, options)
• exposeID(name, options)
• exposeBoolean(name, options)
• exposeInt(name, options)
• exposeFloat(name, options)
• exposeStringList(name, options)
• exposeIDList(name, options)
• exposeBooleanList(name, options)
• exposeIntList(name, options)
• exposeFloatList(name, options)