Constructor field in fragments seems to throw TypeError: nodeAndDefs[responseName].push is not a function

[FlyersWeb]

When I try to query a GraphQL server with a GraphQLObject having a constructor field I get the error TypeError: nodeAndDefs[responseName].push is not a function

Intended outcome

Server should not throw error

Actual outcome

TypeError: nodeAndDefs[responseName].push is not a function

How to reproduce

Create a GraphQL object with a constructor field

    new GraphQLObjectType({
        name : 'FooType',
        fields : {
            ['constructor'] : {
                type : new GraphQLNonNull(GraphQLString)
            },
        }
    })

The query associated:

query dummyQuery {
      ...subscriptionInfo
      __typename
}
fragment subscriptionInfo on SubscriptionType {
  constructor
  __typename
}

Let me know if you need more insights

[FlyersWeb]

referenced by apollographql/apollo-server#387