Express 将获取响应头转发到Apollo graphql响应

我在apollo/Graphql上设置了apollo数据源rest数据源 Expressjs服务器。我想将一些头从fetch响应转发到/graphql响应

以下是流程：

POST /graphql

Graphql makes fetch request using this.get('http://example.com/api')
Response from this fetch contains the header "cache-status"

Response from /graphql
I'd like to include the "cache-status" header from the example.com/api response here in the /graphql response

我在rest数据源类的didReceiveResponse（）方法中看到了头。我不确定这是否是访问和存储它的正确位置。如何在POST/graphql响应中包含“缓存状态”标题？

假设您来自，您可以覆盖

didReceiveResponse

以拦截响应并返回自定义返回值

这里是Typescript中的代码片段，如果需要，可以通过删除参数/返回类型和访问修饰符轻松地将其转换为Javascript

class MyRestDataSource extends RESTDataSource {
  public constructor(baseUrl: string) {
    super();
    this.baseURL = baseUrl;
  }

  public async getSomething(): Promise<any & { headers?: { [key: string]: string } }> {
    // make the get request
    return this.get('path/to/something');
  }

  // intercept response after receiving it
  protected async didReceiveResponse(response: Response, _request: Request) {

    // get the value that is returned by default, by calling didReceiveResponse from the base class
    const defaultReturnValue = await super.didReceiveResponse(response, _request);

    // check if it makes sense to replace return value for this type of request
    if (_request.url.endsWith('path/to/something')) {
      // if yes get the headers from response headers and add it to the returned value
      return {
        ...defaultReturnValue,
        headers: { headerValue: response.headers.get('header_name') },
      };
    }

    return defaultReturnValue;
  }
}

MyRestDataSource类扩展了RESTDataSource{ 公共构造函数（baseUrl:string）{ 超级（）； this.baseURL=baseURL； } 公共异步getSomething（）：承诺{ //发出get请求 返回这个.get（'path/to/something'）； } //接收到响应后拦截响应 受保护的异步didReceiveResponse（响应：响应，\u请求：请求）{ //通过从基类调用didReceiveResponse，获取默认情况下返回的值 const defaultReturnValue=wait super.didReceiveResponse（响应，_请求）； //检查替换此类请求的返回值是否合理 if（_request.url.endsWith（'path/to/something'））{ //如果是，则从响应头中获取头并将其添加到返回值中 返回{ …默认返回值， headers:{headerValue:response.headers.get（'header\u name'）}， }; } 返回默认返回值； } }

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您是否知道如何获取响应标题等？