[Flow] Too restrictive type on optional fields in mutation responses

Describe the bug Consider following schema:

schema {
  mutation: Mutation
}

type MutationResponse {
  success: Boolean
  errors: [String!]
}
  
type Mutation {
  update(id: ID!): MutationResponse
}

and obviously config

generates:
  demo.js:
    - flow

generated type will be

export type MutationResponse = {
  success: ?boolean
  errors: ?Array<string>
}

which means I always need to return success and errors field even if they are null/undefined. All known graphql server implementations tolerate that, so I believe it should be:

export type MutationResponse = {
  success?: ?boolean
  errors?: ?Array<string>
}

which allows not to have field in response.

[xanf]

@adelsz sorry, you’re perfectly right. Let’s say: foo?: ?string sounds better and matches spec

[dotansimha]

Fixed in 0.16.0. Thanks @xanf