graphql/type/definitions

Classes

GraphQLList

List Type Wrapper

A list is a wrapping type which points to another type. Lists are often created within the context of defining the fields of an object type.

Example:

const PersonType = new GraphQLObjectType({
  name: 'Person',
  fields: () => ({
    parents: { type: new GraphQLList(PersonType) },
    children: { type: new GraphQLList(PersonType) },
  })
})

Type Parameters

Constructor

Creates a GraphQLList instance.

Signature:

new GraphQLList(ofType: T)

Arguments

Returns

Members

toString()

Returns this wrapping type as a GraphQL type-reference string.

Signature:

toString(): string

Returns

Example

const source = listType.toString();
 
// source: GraphQL type-reference syntax, for example '[String]'

toJSON()

Returns the JSON representation used when this object is serialized.

Signature:

toJSON(): string

Returns

Example

const json = listType.toJSON();
 
// json: the JSON representation

GraphQLNonNull

Non-Null Type Wrapper

A non-null is a wrapping type which points to another type. Non-null types enforce that their values are never null and can ensure an error is raised if this ever occurs during a request. It is useful for fields which you can make a strong guarantee on non-nullability, for example usually the id field of a database row will never be null.

Example:

const RowType = new GraphQLObjectType({
  name: 'Row',
  fields: () => ({
    id: { type: new GraphQLNonNull(GraphQLString) },
  })
})

Note: the enforcement of non-nullability occurs within the executor.

Type Parameters

Constructor

Creates a GraphQLNonNull instance.

Signature:

new GraphQLNonNull(ofType: T)

Arguments

Returns

Members

toString()

Returns this wrapping type as a GraphQL type-reference string.

Signature:

toString(): string

Returns

Example

const source = nonNullType.toString();
 
// source: GraphQL type-reference syntax, for example 'String!'

toJSON()

Returns the JSON representation used when this object is serialized.

Signature:

toJSON(): string

Returns

Example

const json = nonNullType.toJSON();
 
// json: the JSON representation

GraphQLScalarType

Scalar Type Definition

The leaf values of any request and input values to arguments are Scalars (or Enums) and are defined with a name and a series of functions used to parse input from ast or variables and to ensure validity.

If a type’s serialize function returns null or does not return a value (i.e. it returns undefined) then an error will be raised and a null value will be returned in the response. It is always better to validate

Example:

const OddType = new GraphQLScalarType({
  name: 'Odd',
  serialize(value) {
    if (!Number.isFinite(value)) {
      throw new Error(
        `Scalar "Odd" cannot represent "${value}" since it is not a finite number.`,
      );
    }
 
    if (value % 2 === 0) {
      throw new Error(`Scalar "Odd" cannot represent "${value}" since it is even.`);
    }
    return value;
  }
});

Type Parameters

Constructor

Creates a GraphQLScalarType instance.

Signature:

new GraphQLScalarType(config: Readonly<GraphQLScalarTypeConfig<TInternal, TExternal>>)

Arguments

Returns

Members

toConfig()

Returns a normalized configuration object for this object.

Signature:

toConfig(): { serialize: GraphQLScalarSerializer<TExternal>; parseValue: GraphQLScalarValueParser<TInternal>; parseLiteral: GraphQLScalarLiteralParser<TInternal>; extensions: Readonly<GraphQLScalarTypeExtensions>; extensionASTNodes: ReadonlyArray<ScalarTypeExtensionNode> }

Returns

Example

// Given a GraphQLScalarType instance named scalarType:
const result = scalarType.toConfig();
 
// result contains the toConfig return value

toString()

Returns the schema coordinate identifying this scalar type.

Signature:

toString(): string

Returns

Example

const coordinate = scalarType.toString();
 
// coordinate: the type schema coordinate, for example 'DateTime'

toJSON()

Returns the JSON representation used when this object is serialized.

Signature:

toJSON(): string

Returns

Example

const json = scalarType.toJSON();
 
// json: the JSON representation

GraphQLObjectType

Object Type Definition

Almost all of the GraphQL types you define will be object types. Object types have a name, but most importantly describe their fields.

Example:

const AddressType = new GraphQLObjectType({
  name: 'Address',
  fields: {
    street: { type: GraphQLString },
    number: { type: GraphQLInt },
    formatted: {
      type: GraphQLString,
      resolve(obj) {
        return obj.number + ' ' + obj.street
      }
    }
  }
});

When two types need to refer to each other, or a type needs to refer to itself in a field, you can use a function expression (aka a closure or a thunk) to supply the fields lazily.

Example:

const PersonType = new GraphQLObjectType({
  name: 'Person',
  fields: () => ({
    name: { type: GraphQLString },
    bestFriend: { type: PersonType },
  })
});

Type Parameters

Constructor

Creates a GraphQLObjectType instance.

Signature:

new GraphQLObjectType(config: Readonly<GraphQLObjectTypeConfig<TSource, TContext>>)

Arguments

Returns

Members

getFields()

Returns the fields defined by this type.

Signature:

getFields(): GraphQLFieldMap<TSource, TContext>

Returns

Example

// Given a GraphQLObjectType instance named objectType:
const result = objectType.getFields();
 
// result contains the getFields return value

getInterfaces()

Returns the interfaces implemented by this type.

Signature:

getInterfaces(): readonly GraphQLInterfaceType[]

Returns

Example

// Given a GraphQLObjectType instance named objectType:
const result = objectType.getInterfaces();
 
// result contains the getInterfaces return value

toConfig()

Returns a normalized configuration object for this object.

Signature:

toConfig(): { interfaces: ReadonlyArray<GraphQLInterfaceType>; fields: GraphQLFieldConfigMap<any, any>; extensions: Readonly<GraphQLObjectTypeExtensions<TSource, TContext>>; extensionASTNodes: ReadonlyArray<ObjectTypeExtensionNode> }

Returns

Example

// Given a GraphQLObjectType instance named objectType:
const result = objectType.toConfig();
 
// result contains the toConfig return value

toString()

Returns the schema coordinate identifying this object type.

Signature:

toString(): string

Returns

Example

const coordinate = objectType.toString();
 
// coordinate: the type schema coordinate, for example 'User'

toJSON()

Returns the JSON representation used when this object is serialized.

Signature:

toJSON(): string

Returns

Example

const json = objectType.toJSON();
 
// json: the JSON representation

GraphQLInterfaceType

Interface Type Definition

When a field can return one of a heterogeneous set of types, a Interface type is used to describe what types are possible, what fields are in common across all types, as well as a function to determine which type is actually used when the field is resolved.

Example:

const EntityType = new GraphQLInterfaceType({
  name: 'Entity',
  fields: {
    name: { type: GraphQLString }
  }
});

Constructor

Creates a GraphQLInterfaceType instance.

Signature:

new GraphQLInterfaceType(config: Readonly<GraphQLInterfaceTypeConfig<any, any>>)

Arguments

Returns

Members

getFields()

Returns the fields defined by this type.

Signature:

getFields(): GraphQLFieldMap<any, any>

Returns

Example

// Given a GraphQLInterfaceType instance named interfaceType:
const result = interfaceType.getFields();
 
// result contains the getFields return value

getInterfaces()

Returns the interfaces implemented by this type.

Signature:

getInterfaces(): readonly GraphQLInterfaceType[]

Returns

Example

// Given a GraphQLInterfaceType instance named interfaceType:
const result = interfaceType.getInterfaces();
 
// result contains the getInterfaces return value

toConfig()

Returns a normalized configuration object for this object.

Signature:

toConfig(): { interfaces: ReadonlyArray<GraphQLInterfaceType>; fields: GraphQLFieldConfigMap<any, any>; extensions: Readonly<GraphQLInterfaceTypeExtensions>; extensionASTNodes: ReadonlyArray<InterfaceTypeExtensionNode> }

Returns

Example

// Given a GraphQLInterfaceType instance named interfaceType:
const result = interfaceType.toConfig();
 
// result contains the toConfig return value

toString()

Returns the schema coordinate identifying this interface type.

Signature:

toString(): string

Returns

Example

const coordinate = interfaceType.toString();
 
// coordinate: the type schema coordinate, for example 'Node'

toJSON()

Returns the JSON representation used when this object is serialized.

Signature:

toJSON(): string

Returns

Example

const json = interfaceType.toJSON();
 
// json: the JSON representation

GraphQLUnionType

Union Type Definition

When a field can return one of a heterogeneous set of types, a Union type is used to describe what types are possible as well as providing a function to determine which type is actually used when the field is resolved.

Example:

const PetType = new GraphQLUnionType({
  name: 'Pet',
  types: [ DogType, CatType ],
  resolveType(value) {
    if (value instanceof Dog) {
      return DogType;
    }
    if (value instanceof Cat) {
      return CatType;
    }
  }
});

Constructor

Creates a GraphQLUnionType instance.

Signature:

new GraphQLUnionType(config: Readonly<GraphQLUnionTypeConfig<any, any>>)

Arguments

Returns

Members

getTypes()

Returns the object types included in this union.

Signature:

getTypes(): readonly GraphQLObjectType[]

Returns

Example

// Given a GraphQLUnionType instance named unionType:
const result = unionType.getTypes();
 
// result contains the getTypes return value

toConfig()

Returns a normalized configuration object for this object.

Signature:

toConfig(): { types: ReadonlyArray<GraphQLObjectType>; extensions: Readonly<GraphQLUnionTypeExtensions>; extensionASTNodes: ReadonlyArray<UnionTypeExtensionNode> }

Returns

Example

// Given a GraphQLUnionType instance named unionType:
const result = unionType.toConfig();
 
// result contains the toConfig return value

toString()

Returns the schema coordinate identifying this union type.

Signature:

toString(): string

Returns

Example

const coordinate = unionType.toString();
 
// coordinate: the type schema coordinate, for example 'SearchResult'

toJSON()

Returns the JSON representation used when this object is serialized.

Signature:

toJSON(): string

Returns

Example

const json = unionType.toJSON();
 
// json: the JSON representation

GraphQLEnumType

Enum Type Definition

Some leaf values of requests and input values are Enums. GraphQL serializes Enum values as strings, however internally Enums can be represented by any kind of type, often integers.

Example:

const RGBType = new GraphQLEnumType({
  name: 'RGB',
  values: {
    RED: { value: 0 },
    GREEN: { value: 1 },
    BLUE: { value: 2 }
  }
});

Note: If a value is not provided in a definition, the name of the enum value will be used as its internal value.

Constructor

Creates a GraphQLEnumType instance.

Signature:

new GraphQLEnumType(config: Readonly<GraphQLEnumTypeConfig>)

Arguments

Returns

Members

getValues()

Returns the values defined by this enum type.

Signature:

getValues(): readonly GraphQLEnumValue[]

Returns

Example

// Given a GraphQLEnumType instance named enumType:
const result = enumType.getValues();
 
// result contains the getValues return value

getValue()

Returns the enum value definition for a value name.

Signature:

getValue(name: string): null | undefined | GraphQLEnumValue

Arguments

Returns

Example

// Given a GraphQLEnumType instance named enumType:
const result = enumType.getValue(name);
 
// result contains the getValue return value

serialize()

Serializes a runtime enum value as a GraphQL enum name.

Signature:

serialize(outputValue: unknown): null | undefined | string

Arguments

Returns

Example

// Given a GraphQLEnumType instance named enumType:
const result = enumType.serialize(outputValue);
 
// result contains the serialize return value

parseValue()

Parses a GraphQL enum name from variable input.

Signature:

parseValue(inputValue: unknown): any

Arguments

Returns

Example

// Given a GraphQLEnumType instance named enumType:
const result = enumType.parseValue(inputValue);
 
// result contains the parseValue return value

parseLiteral()

Parses a GraphQL enum name from an AST value literal.

Signature:

parseLiteral(valueNode: ValueNode, _variables: null | undefined | object): any

Arguments

Returns

Example

// Given a GraphQLEnumType instance named enumType:
const result = enumType.parseLiteral(valueNode, _variables);
 
// result contains the parseLiteral return value

toConfig()

Returns a normalized configuration object for this object.

Signature:

toConfig(): { values: object; extensions: Readonly<GraphQLEnumTypeExtensions>; extensionASTNodes: ReadonlyArray<EnumTypeExtensionNode> }

Returns

Example

// Given a GraphQLEnumType instance named enumType:
const result = enumType.toConfig();
 
// result contains the toConfig return value

toString()

Returns the schema coordinate identifying this enum type.

Signature:

toString(): string

Returns

Example

const coordinate = enumType.toString();
 
// coordinate: the type schema coordinate, for example 'Episode'

toJSON()

Returns the JSON representation used when this object is serialized.

Signature:

toJSON(): string

Returns

Example

const json = enumType.toJSON();
 
// json: the JSON representation

GraphQLInputObjectType

Input Object Type Definition

An input object defines a structured collection of fields which may be supplied to a field argument.

Using NonNull will ensure that a value must be provided by the query

Example:

const GeoPoint = new GraphQLInputObjectType({
  name: 'GeoPoint',
  fields: {
    lat: { type: new GraphQLNonNull(GraphQLFloat) },
    lon: { type: new GraphQLNonNull(GraphQLFloat) },
    alt: { type: GraphQLFloat, defaultValue: 0 },
  }
});

Constructor

Creates a GraphQLInputObjectType instance.

Signature:

new GraphQLInputObjectType(config: Readonly<GraphQLInputObjectTypeConfig>)

Arguments

Returns

Members

getFields()

Returns the fields defined by this type.

Signature:

getFields(): GraphQLInputFieldMap

Returns

Example

// Given a GraphQLInputObjectType instance named inputObjectType:
const result = inputObjectType.getFields();
 
// result contains the getFields return value

toConfig()

Returns a normalized configuration object for this object.

Signature:

toConfig(): { fields: GraphQLInputFieldConfigMap; extensions: Readonly<GraphQLInputObjectTypeExtensions>; extensionASTNodes: ReadonlyArray<InputObjectTypeExtensionNode> }

Returns

Example

// Given a GraphQLInputObjectType instance named inputObjectType:
const result = inputObjectType.toConfig();
 
// result contains the toConfig return value

toString()

Returns the schema coordinate identifying this input object type.

Signature:

toString(): string

Returns

Example

const coordinate = inputObjectType.toString();
 
// coordinate: the type schema coordinate, for example 'ReviewInput'

toJSON()

Returns the JSON representation used when this object is serialized.

Signature:

toJSON(): string

Returns

Example

const json = inputObjectType.toJSON();
 
// json: the JSON representation

Functions

isType()

Returns true when the value is any GraphQL type.

Signature:

isType(type: unknown): type is GraphQLType

Arguments

Returns

Example

import { isType, GraphQLString } from 'graphql/type';
 
const result = isType(GraphQLString);
 
// result: true for matching GraphQL types

assertType()

Returns the value as a GraphQL type, or throws if it is not one.

Signature:

assertType(type: unknown): GraphQLType

Arguments

Returns

Example

import { assertType, GraphQLString } from 'graphql/type';
 
const type = assertType(GraphQLString);
 
// type: GraphQLString

isScalarType()

There are predicates for each kind of GraphQL type.

Signature:

isScalarType(type: unknown): type is GraphQLScalarType<unknown, unknown>

Arguments

Returns

Example

import { isScalarType, GraphQLString } from 'graphql/type';
 
const result = isScalarType(GraphQLString);
 
// result: true for matching GraphQL types

assertScalarType()

Returns the value as a GraphQLScalarType, or throws if it is not one.

Signature:

assertScalarType(type: unknown): GraphQLScalarType

Arguments

Returns

Example

import { assertScalarType, GraphQLString } from 'graphql/type';
 
const type = assertScalarType(GraphQLString);
 
// type: GraphQLString

isObjectType()

Returns true when the value is a GraphQLObjectType.

Signature:

isObjectType(type: unknown): type is GraphQLObjectType

Arguments

Returns

Example

import { isObjectType, GraphQLString } from 'graphql/type';
 
const result = isObjectType(GraphQLString);
 
// result: true for matching GraphQL types

assertObjectType()

Returns the value as a GraphQLObjectType, or throws if it is not one.

Signature:

assertObjectType(type: unknown): GraphQLObjectType

Arguments

Returns

Example

import { assertObjectType, GraphQLString } from 'graphql/type';
 
const type = assertObjectType(GraphQLString);
 
// type: GraphQLString

isInterfaceType()

Returns true when the value is a GraphQLInterfaceType.

Signature:

isInterfaceType(type: unknown): type is GraphQLInterfaceType

Arguments

Returns

Example

import { isInterfaceType, GraphQLString } from 'graphql/type';
 
const result = isInterfaceType(GraphQLString);
 
// result: true for matching GraphQL types

assertInterfaceType()

Returns the value as a GraphQLInterfaceType, or throws if it is not one.

Signature:

assertInterfaceType(type: unknown): GraphQLInterfaceType

Arguments

Returns

Example

import { assertInterfaceType, GraphQLString } from 'graphql/type';
 
const type = assertInterfaceType(GraphQLString);
 
// type: GraphQLString

isUnionType()

Returns true when the value is a GraphQLUnionType.

Signature:

isUnionType(type: unknown): type is GraphQLUnionType

Arguments

Returns

Example

import { isUnionType, GraphQLString } from 'graphql/type';
 
const result = isUnionType(GraphQLString);
 
// result: true for matching GraphQL types

assertUnionType()

Returns the value as a GraphQLUnionType, or throws if it is not one.

Signature:

assertUnionType(type: unknown): GraphQLUnionType

Arguments

Returns

Example

import { assertUnionType, GraphQLString } from 'graphql/type';
 
const type = assertUnionType(GraphQLString);
 
// type: GraphQLString

isEnumType()

Returns true when the value is a GraphQLEnumType.

Signature:

isEnumType(type: unknown): type is GraphQLEnumType

Arguments

Returns

Example

import { isEnumType, GraphQLString } from 'graphql/type';
 
const result = isEnumType(GraphQLString);
 
// result: true for matching GraphQL types

assertEnumType()

Returns the value as a GraphQLEnumType, or throws if it is not one.

Signature:

assertEnumType(type: unknown): GraphQLEnumType

Arguments

Returns

Example

import { assertEnumType, GraphQLString } from 'graphql/type';
 
const type = assertEnumType(GraphQLString);
 
// type: GraphQLString

isInputObjectType()

Returns true when the value is a GraphQLInputObjectType.

Signature:

isInputObjectType(type: unknown): type is GraphQLInputObjectType

Arguments

Returns

Example

import { isInputObjectType, GraphQLString } from 'graphql/type';
 
const result = isInputObjectType(GraphQLString);
 
// result: true for matching GraphQL types

assertInputObjectType()

Returns the value as a GraphQLInputObjectType, or throws if it is not one.

Signature:

assertInputObjectType(type: unknown): GraphQLInputObjectType

Arguments

Returns

Example

import { assertInputObjectType, GraphQLString } from 'graphql/type';
 
const type = assertInputObjectType(GraphQLString);
 
// type: GraphQLString

isListType()

Overload 1

Returns true when the value is a GraphQLList.

Signature:

isListType(type: GraphQLInputType): type is GraphQLList<GraphQLInputType>

Arguments

Returns

Example

import { GraphQLList, GraphQLString, isListType } from 'graphql/type';
 
isListType(new GraphQLList(GraphQLString));
 
// true

Overload 2

Returns true when the output type is a GraphQLList.

Signature:

isListType(type: GraphQLOutputType): type is GraphQLList<GraphQLOutputType>

Arguments

Returns

Overload 3

Returns true when the value is a GraphQLList.

Signature:

isListType(type: unknown): type is GraphQLList<GraphQLType>

Arguments

Returns

assertListType()

Returns the value as a GraphQLList, or throws if it is not one.

Signature:

assertListType(type: unknown): GraphQLList<GraphQLType>

Arguments

Returns

Example

import { assertListType, GraphQLString } from 'graphql/type';
 
const type = assertListType(GraphQLString);
 
// type: GraphQLString

isNonNullType()

Overload 1

Returns true when the value is a GraphQLNonNull.

Signature:

isNonNullType(type: GraphQLInputType): type is GraphQLNonNull<GraphQLInputType>

Arguments

Returns

Example

import { GraphQLNonNull, GraphQLString, isNonNullType } from 'graphql/type';
 
isNonNullType(new GraphQLNonNull(GraphQLString));
 
// true

Overload 2

Returns true when the output type is a GraphQLNonNull.

Signature:

isNonNullType(type: GraphQLOutputType): type is GraphQLNonNull<GraphQLOutputType>

Arguments

Returns

Overload 3

Returns true when the value is a GraphQLNonNull.

Signature:

isNonNullType(type: unknown): type is GraphQLNonNull<GraphQLType>

Arguments

Returns

assertNonNullType()

Returns the value as a GraphQLNonNull, or throws if it is not one.

Signature:

assertNonNullType(type: unknown): GraphQLNonNull<GraphQLType>

Arguments

Returns

Example

import { assertNonNullType, GraphQLString } from 'graphql/type';
 
const type = assertNonNullType(GraphQLString);
 
// type: GraphQLString

isInputType()

Returns true when the value can be used as a GraphQL input type.

Signature:

isInputType(type: unknown): type is GraphQLInputType

Arguments

Returns

Example

import { isInputType, GraphQLString } from 'graphql/type';
 
const result = isInputType(GraphQLString);
 
// result: true for matching GraphQL types

assertInputType()

Returns the value as a GraphQL input type, or throws if it is not one.

Signature:

assertInputType(type: unknown): GraphQLInputType

Arguments

Returns

Example

import { assertInputType, GraphQLString } from 'graphql/type';
 
const type = assertInputType(GraphQLString);
 
// type: GraphQLString

isOutputType()

Returns true when the value can be used as a GraphQL output type.

Signature:

isOutputType(type: unknown): type is GraphQLOutputType

Arguments

Returns

Example

import { isOutputType, GraphQLString } from 'graphql/type';
 
const result = isOutputType(GraphQLString);
 
// result: true for matching GraphQL types

assertOutputType()

Returns the value as a GraphQL output type, or throws if it is not one.

Signature:

assertOutputType(type: unknown): GraphQLOutputType

Arguments

Returns

Example

import { assertOutputType, GraphQLString } from 'graphql/type';
 
const type = assertOutputType(GraphQLString);
 
// type: GraphQLString

isLeafType()

Returns true when the value is a GraphQL scalar or enum type.

Signature:

isLeafType(type: unknown): type is GraphQLLeafType

Arguments

Returns

Example

import { isLeafType, GraphQLString } from 'graphql/type';
 
const result = isLeafType(GraphQLString);
 
// result: true for matching GraphQL types

assertLeafType()

Returns the value as a GraphQL leaf type, or throws if it is not one.

Signature:

assertLeafType(type: unknown): GraphQLLeafType

Arguments

Returns

Example

import { assertLeafType, GraphQLString } from 'graphql/type';
 
const type = assertLeafType(GraphQLString);
 
// type: GraphQLString

isCompositeType()

Returns true when the value is a GraphQL object, interface, or union type.

Signature:

isCompositeType(type: unknown): type is GraphQLCompositeType

Arguments

Returns

Example

import { isCompositeType, GraphQLString } from 'graphql/type';
 
const result = isCompositeType(GraphQLString);
 
// result: true for matching GraphQL types

assertCompositeType()

Returns the value as a GraphQL composite type, or throws if it is not one.

Signature:

assertCompositeType(type: unknown): GraphQLCompositeType

Arguments

Returns

Example

import { assertCompositeType, GraphQLString } from 'graphql/type';
 
const type = assertCompositeType(GraphQLString);
 
// type: GraphQLString

isAbstractType()

Returns true when the value is a GraphQL interface or union type.

Signature:

isAbstractType(type: unknown): type is GraphQLAbstractType

Arguments

Returns

Example

import { isAbstractType, GraphQLString } from 'graphql/type';
 
const result = isAbstractType(GraphQLString);
 
// result: true for matching GraphQL types

assertAbstractType()

Returns the value as a GraphQL abstract type, or throws if it is not one.

Signature:

assertAbstractType(type: unknown): GraphQLAbstractType

Arguments

Returns

Example

import { assertAbstractType, GraphQLString } from 'graphql/type';
 
const type = assertAbstractType(GraphQLString);
 
// type: GraphQLString

isWrappingType()

Returns true when the value is a GraphQL list or non-null wrapper type.

Signature:

isWrappingType(type: unknown): type is GraphQLWrappingType

Arguments

Returns

Example

import { isWrappingType, GraphQLString } from 'graphql/type';
 
const result = isWrappingType(GraphQLString);
 
// result: true for matching GraphQL types

assertWrappingType()

Returns the value as a GraphQL wrapping type, or throws if it is not one.

Signature:

assertWrappingType(type: unknown): GraphQLWrappingType

Arguments

Returns

Example

import { assertWrappingType, GraphQLString } from 'graphql/type';
 
const type = assertWrappingType(GraphQLString);
 
// type: GraphQLString

isNullableType()

Returns true when the value is a GraphQL type that can accept null.

Signature:

isNullableType(type: unknown): type is GraphQLNullableType

Arguments

Returns

Example

import { isNullableType, GraphQLString } from 'graphql/type';
 
const result = isNullableType(GraphQLString);
 
// result: true for matching GraphQL types

assertNullableType()

Returns the value as a nullable GraphQL type, or throws if it is not one.

Signature:

assertNullableType(type: unknown): GraphQLNullableType

Arguments

Returns

Example

import { assertNullableType, GraphQLString } from 'graphql/type';
 
const type = assertNullableType(GraphQLString);
 
// type: GraphQLString

getNullableType()

Overload 1

Returns the nullable type.

Signature:

getNullableType(type: null | undefined): void

Arguments

Example

import { getNullableType } from 'graphql/type';
 
getNullableType(null);
 
// undefined

Overload 2

Returns the nullable type after removing one non-null wrapper.

Type Parameters

Signature:

getNullableType<T extends GraphQLNullableType>(type: T | GraphQLNonNull<T>): T

Arguments

Returns

Overload 3

Returns the nullable type after removing one non-null wrapper.

Signature:

getNullableType(type: null | undefined | GraphQLType): GraphQLNullableType | undefined

Arguments

Returns

isNamedType()

Returns true when the value is a GraphQL named type.

Signature:

isNamedType(type: unknown): type is GraphQLNamedType

Arguments

Returns

Example

import { isNamedType, GraphQLString } from 'graphql/type';
 
const result = isNamedType(GraphQLString);
 
// result: true for matching GraphQL types

assertNamedType()

Returns the value as a GraphQL named type, or throws if it is not one.

Signature:

assertNamedType(type: unknown): GraphQLNamedType

Arguments

Returns

Example

import { assertNamedType, GraphQLString } from 'graphql/type';
 
const type = assertNamedType(GraphQLString);
 
// type: GraphQLString

getNamedType()

Overload 1

Returns the named type.

Signature:

getNamedType(type: null | undefined): void

Arguments

Example

import { getNamedType } from 'graphql/type';
 
getNamedType(null);
 
// undefined

Overload 2

Returns the named input type after unwrapping all list and non-null wrappers.

Signature:

getNamedType(type: GraphQLInputType): GraphQLNamedInputType

Arguments

Returns

Overload 3

Returns the named output type after unwrapping all list and non-null wrappers.

Signature:

getNamedType(type: GraphQLOutputType): GraphQLNamedOutputType

Arguments

Returns

Overload 4

Returns the named type after unwrapping all list and non-null wrappers.

Signature:

getNamedType(type: GraphQLType): GraphQLNamedType

Arguments

Returns

Overload 5

Returns the named type after unwrapping all list and non-null wrappers.

Signature:

getNamedType(type: null | undefined | GraphQLType): GraphQLNamedType | undefined

Arguments

Returns

resolveReadonlyArrayThunk()

Resolves a thunked readonly array.

Type Parameters

Signature:

resolveReadonlyArrayThunk<T>(thunk: ThunkReadonlyArray<T>): readonly T[]

Arguments

Returns

Example

import { GraphQLString, resolveReadonlyArrayThunk } from 'graphql/type';
 
const fields = resolveReadonlyArrayThunk(() => [GraphQLString]);
 
// fields: [GraphQLString]

resolveObjMapThunk()

Resolves a thunked object map.

Type Parameters

Signature:

resolveObjMapThunk<T>(thunk: ThunkObjMap<T>): object

Arguments

Returns

Example

import { GraphQLString, resolveObjMapThunk } from 'graphql/type';
 
const fields = resolveObjMapThunk(() => ({ name: GraphQLString }));
 
// fields.name: GraphQLString

isRequiredArgument()

Returns true when the argument is non-null and has no default value.

Signature:

isRequiredArgument(arg: GraphQLArgument): boolean

Arguments

Returns

Example

import { isRequiredArgument, GraphQLString } from 'graphql/type';
 
const result = isRequiredArgument(GraphQLString);
 
// result: true for matching GraphQL types

isRequiredInputField()

Returns true when the input field is non-null and has no default value.

Signature:

isRequiredInputField(field: GraphQLInputField): boolean

Arguments

Returns

Example

import { isRequiredInputField, GraphQLString } from 'graphql/type';
 
const result = isRequiredInputField(GraphQLString);
 
// result: true for matching GraphQL types

Types

GraphQLType

Type alias. These are all of the possible kinds of types.

type GraphQLType = GraphQLScalarType | GraphQLObjectType | GraphQLInterfaceType | GraphQLUnionType | GraphQLEnumType | GraphQLInputObjectType | GraphQLList<GraphQLType> | GraphQLNonNull<GraphQLScalarType | GraphQLObjectType | GraphQLInterfaceType | GraphQLUnionType | GraphQLEnumType | GraphQLInputObjectType | GraphQLList<GraphQLType>>;

GraphQLInputType

Type alias. These types may be used as input types for arguments and directives.

type GraphQLInputType = GraphQLScalarType | GraphQLEnumType | GraphQLInputObjectType | GraphQLList<GraphQLInputType> | GraphQLNonNull<GraphQLScalarType | GraphQLEnumType | GraphQLInputObjectType | GraphQLList<GraphQLInputType>>;

GraphQLOutputType

Type alias. These types may be used as output types as the result of fields.

type GraphQLOutputType = GraphQLScalarType | GraphQLObjectType | GraphQLInterfaceType | GraphQLUnionType | GraphQLEnumType | GraphQLList<GraphQLOutputType> | GraphQLNonNull<GraphQLScalarType | GraphQLObjectType | GraphQLInterfaceType | GraphQLUnionType | GraphQLEnumType | GraphQLList<GraphQLOutputType>>;

GraphQLLeafType

Type alias. These types may describe types which may be leaf values.

type GraphQLLeafType = GraphQLScalarType | GraphQLEnumType;

GraphQLCompositeType

Type alias. These types may describe the parent context of a selection set.

type GraphQLCompositeType = GraphQLObjectType | GraphQLInterfaceType | GraphQLUnionType;

GraphQLAbstractType

Type alias. These types may describe the parent context of a selection set.

type GraphQLAbstractType = GraphQLInterfaceType | GraphQLUnionType;

GraphQLWrappingType

Type alias. These types wrap and modify other types

type GraphQLWrappingType = GraphQLList<GraphQLType> | GraphQLNonNull<GraphQLType>;

GraphQLNullableType

Type alias. These types can all accept null as a value.

type GraphQLNullableType = GraphQLScalarType | GraphQLObjectType | GraphQLInterfaceType | GraphQLUnionType | GraphQLEnumType | GraphQLInputObjectType | GraphQLList<GraphQLType>;

GraphQLNamedType

Type alias. These named types do not include modifiers like List or NonNull.

type GraphQLNamedType = GraphQLNamedInputType | GraphQLNamedOutputType;

GraphQLNamedInputType

Type alias. A named GraphQL type that can be used as an input type.

type GraphQLNamedInputType = GraphQLScalarType | GraphQLEnumType | GraphQLInputObjectType;

GraphQLNamedOutputType

Type alias. A named GraphQL type that can be used as an output type.

type GraphQLNamedOutputType = GraphQLScalarType | GraphQLObjectType | GraphQLInterfaceType | GraphQLUnionType | GraphQLEnumType;

ThunkReadonlyArray

Type alias. Used while defining GraphQL types to allow for circular references in otherwise immutable type definitions.

Type Parameters

type ThunkReadonlyArray<T> = (): ReadonlyArray<T> | ReadonlyArray<T>;

ThunkObjMap

Type alias. A thunk that resolves to an object map.

Type Parameters

type ThunkObjMap<T> = (): object | object;

GraphQLScalarTypeExtensions

Interface. Custom extensions

Remarks: Use a unique identifier name for your extension, for example the name of your library or project. Do not use a shortened identifier as this increases the risk of conflicts. We recommend you add at most one extension field, an object which can contain all the values you need.

GraphQLScalarSerializer

Type alias. Serializes a runtime value as a scalar output value.

Type Parameters

type GraphQLScalarSerializer<TExternal> = (outputValue: unknown): TExternal;

GraphQLScalarValueParser

Type alias. Parses a runtime input value as a scalar input value.

Type Parameters

type GraphQLScalarValueParser<TInternal> = (inputValue: unknown): TInternal;

GraphQLScalarLiteralParser

Type alias. Parses a GraphQL value literal as a scalar input value.

Type Parameters

type GraphQLScalarLiteralParser<TInternal> = (valueNode: ValueNode, variables?: null | undefined | object): TInternal;

GraphQLScalarTypeConfig

Interface. Configuration used to construct a GraphQLScalarType.

Type Parameters

Members

GraphQLObjectTypeExtensions

Interface. Custom extensions

Remarks: Use a unique identifier name for your extension, for example the name of your library or project. Do not use a shortened identifier as this increases the risk of conflicts. We recommend you add at most one extension field, an object which can contain all the values you need.

We’ve provided these template arguments because this is an open type and you may find them useful.

Type Parameters

GraphQLObjectTypeConfig

Interface. Configuration used to construct a GraphQLObjectType.

Type Parameters

Members

GraphQLTypeResolver

Type alias. Resolves the concrete object type for an abstract GraphQL type.

Type Parameters

type GraphQLTypeResolver<TSource, TContext> = (value: TSource, context: TContext, info: GraphQLResolveInfo, abstractType: GraphQLAbstractType): Promise<string | undefined> | string | undefined;

GraphQLIsTypeOfFn

Type alias. Checks whether a runtime value belongs to a GraphQL object type.

Type Parameters

type GraphQLIsTypeOfFn<TSource, TContext> = (source: TSource, context: TContext, info: GraphQLResolveInfo): Promise<boolean> | boolean;

GraphQLFieldResolver

Type alias. Resolves the runtime value for a GraphQL field.

Type Parameters

type GraphQLFieldResolver<TSource, TContext, TArgs = any, TResult = unknown> = (source: TSource, args: TArgs, context: TContext, info: GraphQLResolveInfo): TResult;

GraphQLResolveInfo

Interface. Information about the currently executing GraphQL field.

Members

GraphQLFieldExtensions

Interface. Custom extensions

Remarks: Use a unique identifier name for your extension, for example the name of your library or project. Do not use a shortened identifier as this increases the risk of conflicts. We recommend you add at most one extension field, an object which can contain all the values you need.

We’ve provided these template arguments because this is an open type and you may find them useful.

Type Parameters

GraphQLFieldConfig

Interface. Configuration used to define a GraphQL field.

Type Parameters

Members

GraphQLFieldConfigArgumentMap

Type alias. A map of argument names to argument configuration objects.

type GraphQLFieldConfigArgumentMap = object;

GraphQLArgumentExtensions

Interface. Custom extensions

Remarks: Use a unique identifier name for your extension, for example the name of your library or project. Do not use a shortened identifier as this increases the risk of conflicts. We recommend you add at most one extension field, an object which can contain all the values you need.

GraphQLArgumentConfig

Interface. Configuration used to define a GraphQL argument.

Members

GraphQLFieldConfigMap

Type alias. A map of field names to field configuration objects.

Type Parameters

type GraphQLFieldConfigMap<TSource, TContext> = object;

GraphQLField

Interface. A resolved GraphQL field definition.

Type Parameters

Members

GraphQLArgument

Interface. A resolved GraphQL argument definition.

Members

GraphQLFieldMap

Type alias. A map of field names to resolved field definitions.

Type Parameters

type GraphQLFieldMap<TSource, TContext> = object;

GraphQLInterfaceTypeExtensions

Interface. Custom extensions

Remarks: Use a unique identifier name for your extension, for example the name of your library or project. Do not use a shortened identifier as this increases the risk of conflicts. We recommend you add at most one extension field, an object which can contain all the values you need.

GraphQLInterfaceTypeConfig

Interface. Configuration used to construct a GraphQLInterfaceType.

Type Parameters

Members

GraphQLUnionTypeExtensions

Interface. Custom extensions

Remarks: Use a unique identifier name for your extension, for example the name of your library or project. Do not use a shortened identifier as this increases the risk of conflicts. We recommend you add at most one extension field, an object which can contain all the values you need.

GraphQLUnionTypeConfig

Interface. Configuration used to construct a GraphQLUnionType.

Type Parameters

Members

GraphQLEnumTypeExtensions

Interface. Custom extensions

Remarks: Use a unique identifier name for your extension, for example the name of your library or project. Do not use a shortened identifier as this increases the risk of conflicts. We recommend you add at most one extension field, an object which can contain all the values you need.

GraphQLEnumTypeConfig

Interface. Configuration used to construct a GraphQLEnumType.

Members

GraphQLEnumValueConfigMap

Type alias. A map of enum value names to enum value configuration objects.

type GraphQLEnumValueConfigMap = object;

GraphQLEnumValueExtensions

Interface. Custom extensions

Remarks: Use a unique identifier name for your extension, for example the name of your library or project. Do not use a shortened identifier as this increases the risk of conflicts. We recommend you add at most one extension field, an object which can contain all the values you need.

GraphQLEnumValueConfig

Interface. Configuration used to define a GraphQL enum value.

Members

GraphQLEnumValue

Interface. A resolved GraphQL enum value definition.

Members

GraphQLInputObjectTypeExtensions

Interface. Custom extensions

Remarks: Use a unique identifier name for your extension, for example the name of your library or project. Do not use a shortened identifier as this increases the risk of conflicts. We recommend you add at most one extension field, an object which can contain all the values you need.

GraphQLInputObjectTypeConfig

Interface. Configuration used to construct a GraphQLInputObjectType.

Members

GraphQLInputFieldExtensions

Interface. Custom extensions

Remarks: Use a unique identifier name for your extension, for example the name of your library or project. Do not use a shortened identifier as this increases the risk of conflicts. We recommend you add at most one extension field, an object which can contain all the values you need.

GraphQLInputFieldConfig

Interface. Configuration used to define a GraphQL input field.

Members

GraphQLInputFieldConfigMap

Type alias. A map of input field names to input field configuration objects.

type GraphQLInputFieldConfigMap = object;

GraphQLInputField

Interface. A resolved GraphQL input field definition.

Members

GraphQLInputFieldMap

Type alias. A map of input field names to resolved input field definitions.

type GraphQLInputFieldMap = object;