graphql - @include 指令中引用的变量无效

Question

我将在这里复制我的问题，希望有人可以提示我哪里出错了。

这是 GraphCool 上的架构：

type Reservation implements Node {
  createdAt: DateTime!
    id: ID!@isUnique
  updatedAt: DateTime!
    user: User @relation(name: "UserReservations")
}

type User implements Node {
  createdAt: DateTime!
    id: ID!@isUnique
  updatedAt: DateTime!
    reservations: [Reservation!] !@relation(name: "UserReservations")
}

这是我的 Angular 代码中的一个片段：

fragment reservation on Reservation {
  id,
  user @include(
    if :$is_admin) {
    id
  }
}

这是我的 GraphQL 查询：

mutation($id: ID!, $is_admin: Boolean = true) {
  createReservation(userId: $id) {
    ...reservation
  }
}
$ {
  RESERVATION_FRAGMENT.reservation
}

在 GraphCool 上使用执行成功调用上述突变apollo.watchQuery，但客户端产生以下错误：

Error: Invalid variable referenced in @include directive.
at directives.js: 42
at Array.some( < anonymous > )
at Object.shouldInclude(directives.js: 20)
at graphql.js: 27
at Array.forEach( < anonymous > )
at executeSelectionSet(graphql.js: 26)
at graphql.js: 55
at Array.forEach( < anonymous > )
at executeSelectionSet(graphql.js: 26)
at graphql.js: 94