1. Given you have the following classes defined:

#[StringBased] final class GivenName { private function __construct(public readonly string $value) {} } #[StringBased] final class FamilyName { private function __construct(public readonly string $value) {} } final class FullName { public function __construct( public readonly GivenName $givenName, public readonly FamilyName $familyName, ) {} } #[Description('honorific title of a person')] enum HonorificTitle { #[Description('for men, regardless of marital status, who do not have another professional or academic title')] case MR; #[Description('for married women who do not have another professional or academic title')] case MRS; #[Description('for girls, unmarried women and married women who continue to use their maiden name')] case MISS; #[Description('for women, regardless of marital status or when marital status is unknown')] case MS; #[Description('for any other title that does not match the above')] case OTHER; } #[Description('A contact in the system')] final class Contact { public function __construct( public readonly HonorificTitle $title, public readonly FullName $name, #[Description('Whether the contact is registered or not')] public bool $isRegistered = false, ) {} } #[ListBased(itemClassName: Contact::class)] final class Contacts { private function __construct(private readonly array $contacts) {} }

1. ...and this API class:

// ... final class SomeApi { #[Query] public function findContactsByFamilyName(FamilyName $familyName): Contacts { // ... } #[Mutation] public function addContact(Contact $newContact): bool { // ... } }

1. The GraphQL schema is more verbose now:

// ... $generator = new GraphQLGenerator(); $schema = $generator->generate(SomeApi::class)->render(); $expectedSchema = <<<GRAPHQL type Query {  findContactsByFamilyName(familyName: FamilyName!): [Contact!]! }  type Mutation {  addContact(newContact: ContactInput!): Boolean! }  scalar FamilyName  """ honorific title of a person """ enum HonorificTitle {  """  for men, regardless of marital status, who do not have another professional or academic title  """  MR  """  for married women who do not have another professional or academic title  """  MRS  """  for girls, unmarried women and married women who continue to use their maiden name  """  MISS  """  for women, regardless of marital status or when marital status is unknown  """  MS  """  for any other title that does not match the above  """  OTHER }  scalar GivenName  type FullName {  givenName: GivenName!  familyName: FamilyName! }  type Contact {  """ honorific title of a person """  title: HonorificTitle!  name: FullName!  """ Whether the contact is registered or not """  isRegistered: Boolean }  input FullNameInput {  givenName: GivenName!  familyName: FamilyName! }  input ContactInput {  """ honorific title of a person """  title: HonorificTitle!  name: FullNameInput!  """ Whether the contact is registered or not """  isRegistered: Boolean }  GRAPHQL; assert($schema === $expectedSchema);

#[StringBased(minLength: 1, maxLength: 200)] final class Name { private function __construct(public readonly string $value) {} } #[IntegerBased(minimum: 1, maximum: 130)] final class Age { private function __construct(public readonly int $value) {} } #[ListBased(itemClassName: Name::class, minCount: 1, maxCount: 5)] final class Names { private function __construct(private readonly array $names) {} } final class SomeApi { #[Query] public function oldestPerson(Names $someNames): ?Age { // ... } } $generator = new GraphQLGenerator(); $schema = $generator->generate(SomeApi::class)->render(); $expectedSchema = <<<GRAPHQL """ Custom constraint directive (see https://www.npmjs.com/package/graphql-constraint-directive) """ directive @constraint(minLength: Int maxLength: Int pattern: String format: String min: Int max: Int minItems: Int maxItems: Int) on FIELD_DEFINITION | SCALAR | ARGUMENT_DEFINITION | INPUT_FIELD_DEFINITION   type Query {  oldestPerson(someNames: [Name!]! @constraint(minItems: 1 maxItems: 5)): Age }  """  *Constraints:* * Minimum length: `1` * Maximum length: `200` """ scalar Name @constraint(minLength: 1 maxLength: 200)  """  *Constraints:* * Minimum value: `1` * Maximum value: `130` """ scalar Age @constraint(min: 1 max: 130)  GRAPHQL; assert($schema === $expectedSchema);

final class User { public function __construct( public readonly string $givenName, public readonly string $familyName, ) {} } #[ListBased(itemClassName: User::class)] final class Users { } final class SomeApi { #[Query] public function users(): ?Users { // ... } } $generator = new GraphQLGenerator(); $customResolvers = CustomResolvers::create(new CustomResolver('User', 'fullName', fn (User $user): string => $user->givenName . ' ' . $user->familyName)); $schema = $generator->generate(SomeApi::class, $customResolvers)->render(); $expectedSchema = <<<GRAPHQL type Query {  users: [User!] }  type User {  givenName: String!  familyName: String!  fullName: String! }  GRAPHQL; assert($schema === $expectedSchema);