小编kaz*_*vac的帖子

我有以下基本代码片段，我的目标是从 获取 fullDocument 属性，obj: ChangeEvent但是我无法访问此属性 ( Property 'fullDocument' does not exist on type 'ChangeEvent<any>')。我可以访问的唯一属性是 _id、clusterTime 和 operationType。有什么我遗漏的，还是我应该非直接查询 fullDocument ( obj['fullDocument'])？

const changeStream = this.model.watch([], { fullDocument: 'updateLookup' })
      .on('change', obj => {
        console.log(obj.fullDocument);
      });

有没有办法提示 TS 泛型参数的出现用于泛型推理？

type Handler = <T>( // <-- if T is unspecified in method definition and call how can i tell ts to infer it to Ta from Params<Ta> and not Tb of the input?
  func: (params: Params<Ta>) => any,
  input: Tb
) => string;

代码示例

type Params<T = Record<string, unknown>> = {
  p: T;
  // other metadata
}

type Handler = <T>( // <-- if T is unspecified how can i tell ts to infer it from Params<T>? …