graphql/utilities/values

Functions

astFromValue()

Produces a GraphQL Value AST given a JavaScript object. Function will match JavaScript/JSON values to GraphQL AST schema format by using suggested GraphQLInputType. For example:

astFromValue(“value”, GraphQLString)

A GraphQL type must be provided, which will be used to interpret different JavaScript values.

JSON Value	GraphQL Value
Object	Input Object
Array	List
Boolean	Boolean
String	String / Enum Value
Number	Int / Float
Unknown	Enum Value
null	NullValue

Signature:

astFromValue(value: unknown, type: GraphQLInputType): null | undefined | ValueNode

Arguments

Name	Type	Description
value	`unknown`	The runtime value to convert.
type	`GraphQLInputType`	The GraphQL type to inspect.

Returns

Type	Description
`null \| undefined \| ValueNode`	A GraphQL value AST for the provided JavaScript value, or null when no literal can represent it.

Example

import { astFromValue } from 'graphql/utilities';
 
const result = astFromValue(value, type);
 
// result contains the astFromValue return value

coerceInputValue()

Coerces a JavaScript value given a GraphQL Input Type.

Signature:

coerceInputValue(inputValue: unknown, type: GraphQLInputType, onError: (path: ReadonlyArray<string | number>, invalidValue: unknown, error: GraphQLError) => void): unknown

Arguments

Name	Type	Default	Description
inputValue	`unknown`		The runtime input value to coerce.
type	`GraphQLInputType`		The GraphQL type to inspect.
onError	`(path: ReadonlyArray<string \| number>, invalidValue: unknown, error: GraphQLError) => void`	`defaultOnError`	The callback invoked for each coercion error.

Returns

Type	Description
`unknown`	The coerced value, or undefined if coercion failed and errors were reported.

Example

import { coerceInputValue } from 'graphql/utilities';
 
const result = coerceInputValue(inputValue, type);
 
// result contains the coerceInputValue return value

typeFromAST()

Overload 1

Given a Schema and an AST node describing a type, return a GraphQLType definition which applies to that type. For example, if provided the parsed AST node for [User], a GraphQLList instance will be returned, containing the type called “User” found in the schema. If a type called “User” is not found in the schema, then undefined will be returned.

Signature:

typeFromAST(schema: GraphQLSchema, typeNode: NamedTypeNode): GraphQLNamedType | undefined

Arguments

Name	Type	Description
schema	`GraphQLSchema`	The GraphQL schema to use.
typeNode	`NamedTypeNode`	The GraphQL type AST node to resolve.

Returns

Type	Description
`GraphQLNamedType \| undefined`	The GraphQL type referenced by the AST node, or undefined if it cannot be resolved.

Example

import { GraphQLString, typeFromAST } from 'graphql/utilities';
import { parseType } from 'graphql/language';
 
typeFromAST(schema, parseType('String'));
 
// GraphQLString

Overload 2

Resolves a list type AST node against a schema.

Signature:

typeFromAST(schema: GraphQLSchema, typeNode: ListTypeNode): GraphQLList<any> | undefined

Arguments

Name	Type	Description
schema	`GraphQLSchema`	The GraphQL schema to use.
typeNode	`ListTypeNode`	The list type AST node to resolve.

Returns

Type	Description
`GraphQLList<any> \| undefined`	The GraphQL list type referenced by the AST node, or undefined if it cannot be resolved.

Overload 3

Resolves a non-null type AST node against a schema.

Signature:

typeFromAST(schema: GraphQLSchema, typeNode: NonNullTypeNode): GraphQLNonNull<any> | undefined

Arguments

Name	Type	Description
schema	`GraphQLSchema`	The GraphQL schema to use.
typeNode	`NonNullTypeNode`	The non-null type AST node to resolve.

Returns

Type	Description
`GraphQLNonNull<any> \| undefined`	The GraphQL non-null type referenced by the AST node, or undefined if it cannot be resolved.

Overload 4

Resolves a type AST node against a schema.

Signature:

typeFromAST(schema: GraphQLSchema, typeNode: TypeNode): GraphQLType | undefined

Arguments

Name	Type	Description
schema	`GraphQLSchema`	The GraphQL schema to use.
typeNode	`TypeNode`	The GraphQL type AST node to resolve.

Returns

Type	Description
`GraphQLType \| undefined`	The GraphQL type referenced by the AST node, or undefined if it cannot be resolved.

valueFromAST()

Produces a JavaScript value given a GraphQL Value AST.

A GraphQL type must be provided, which will be used to interpret different GraphQL Value literals.

Returns undefined when the value could not be validly coerced according to the provided type.

GraphQL Value	JSON Value
Input Object	Object
List	Array
Boolean	Boolean
String	String
Int / Float	Number
Enum Value	Unknown
NullValue	null

Signature:

valueFromAST(valueNode: null | undefined | ValueNode, type: GraphQLInputType, variables?: null | undefined | object): unknown

Arguments

Name	Type	Description
valueNode	`null \| undefined \| ValueNode`	The GraphQL value AST node to convert.
type	`GraphQLInputType`	The GraphQL type to inspect.
variables?	`null \| undefined \| object`	Optional runtime variable values keyed by variable name.

Returns

Type	Description
`unknown`	The coerced JavaScript value, or undefined if the AST value cannot be coerced to the type.

Example

import { valueFromAST } from 'graphql/utilities';
 
const result = valueFromAST(valueNode, type);
 
// result contains the valueFromAST return value

valueFromASTUntyped()

Produces a JavaScript value given a GraphQL Value AST.

Unlike valueFromAST(), no type is provided. The resulting JavaScript value will reflect the provided GraphQL value AST.

GraphQL Value	JavaScript Value
Input Object	Object
List	Array
Boolean	Boolean
String / Enum	String
Int / Float	Number
Null	null

Signature:

valueFromASTUntyped(valueNode: ValueNode, variables?: null | undefined | object): unknown

Arguments

Name	Type	Description
valueNode	`ValueNode`	The GraphQL value AST node to convert.
variables?	`null \| undefined \| object`	Optional runtime variable values keyed by variable name.

Returns

Type	Description
`unknown`	The JavaScript value represented by the GraphQL value AST.

Example

import { parseValue } from 'graphql/language';
import { valueFromASTUntyped } from 'graphql/utilities';
 
const value = valueFromASTUntyped(parseValue('[1, 2, 3]'));
 
// value: [1, 2, 3]

Validation graphql/validation