Apollo-link-rest: 突变原因：ERROR 错误：网络错误：全局未定义

目前使用 Angular 7，apollo-rest 链接 0.7.3

我终于让突变部分工作，并且存在一个问题，即global未初始化并导致此错误：

core.js:15724 ERROR Error: Network error: global is not defined
    at new ApolloError (bundle.esm.js:60)
    at Object.error (bundle.esm.js:1032)
    at notifySubscription (Observable.js:134)
    at onNotify (Observable.js:165)
    at SubscriptionObserver.error (Observable.js:224)
    at Object.error (Observable.js:463)
    at notifySubscription (Observable.js:134)
    at onNotify (Observable.js:165)
    at SubscriptionObserver.error (Observable.js:224)
    at bundle.umd.js:807

我初始化客户端

const restLink = new RestLink({
    uri: 'http://localhost:5000/api',
    credentials: 'same-origin',
    headers: {
      Accept: 'application/json',
      'Content-Type': 'application/json'
    }
  });
  return {
    link: restLink,
    cache
  };

我有这个突变：

export const addTodo = gql`
    mutation addTodo($input: Todo!){
      addTodo(input: $input) @rest( type: "Todo", method: "POST", path: "/todos" ) {
       ...todoFragment
      }
  }
  ${todoFragment}
`;

我是这样执行的：

 add(text: string): void {

    this.apollo.mutate({
      mutation: addTodo,
      variables: {
        input: {
          description: text,
          completed: false
        }
      }
    }).subscribe(({data}) => {
      console.log('got data', data);
    }, (error) => {
      console.log('there was an error sending the query', error);
    });

导致错误的行在图片下方

知道为什么这个global.FileList全局对象是未定义的吗？

// FileList/File are only available in some browser contexts
        // Notably: *not available* in react-native.
        if ((global.FileList && object instanceof FileList) ||
            (global.File && object instanceof File)) {
            // Object is a FileList or File object => no keys to convert!
            return object;
        }