Why does `ObjectTypeDefinitionNode` define `fields` as optional?

[magicmark]

graphql-js/src/language/ast.ts

Line 591 in 9032db1

readonly fields?: ReadonlyArray<FieldDefinitionNode>;

(Is it ever possible to define an Object without any fields? Spec doesn't explicitly state that, but type Foo { } doesn't parse in this implementation.... (should this be clarified in the spec?)

[yaacovCR]

I believe that although "type Foo { }" does not parse, it's possible to define "type Foo" (and then even extend that type later with additional fields to make it valid).

[benjie]

That's correct.

"""
The 'Foo' type
"""
type Foo @someDirective

"""
Bar bar black sheep, have you any wool?
"""
type Bar { a: Int }

extend type Foo { bar: Bar }

[magicmark]

ah gotcha, thanks!