首先，我们将简化示例：

type SubType = { dates?: string, location?: string };
type Foo = (arg: SubType) => void;

type SuperType = { dates?: string };
type Bar = (arg: SuperType) => void;

function convert (arg: Foo): Bar {
  return arg;
  //     ^ Cannot return `arg` because property `location` is missing in `SuperType` [1] but exists in `SubType` [2] in the first argument.
}

换句话说，我们只是使用类型转换将Foo转换为Bar：

const anyObj = ({}: any);

((anyObj: Foo): Bar);
//        ^ Cannot cast object literal to `Bar` because property `location` is missing in `SuperType` [1] but exists in `SubType` [2] in the first argument.

或者我们可以说，我们将SuperType转换为SubType

((anyObj: SuperType): SubType);
//        ^ Cannot cast `anyObj` to `SubType` because property `location` is missing in `SuperType` [1] but exists in `SubType` [2].

要将SuperType转换为SubType，我们可以使用$Shape：
复制所提供类型的形状，但将每个字段标记为可选。

// Correct
((anyObj: SuperType): $Shape<SubType>);

顶级域名：

export type SearchContextType = {
  dates: DateRange,
  location: GoogleMapPosition,
  update: ($Shape<{ dates?: DateRange, location?: GoogleMapPosition }>) => void
  //       ^ add `$Shape`
};

纠正示例