在定义流文字类型时使用外部常量 [英] Use external constant when defining flow literal type

问题描述

我想以流文字类型使用从包中导入的常量，并静态检查开关；

I would like to use an imported constant from a package in a flow literal type and static check the switch;

有没有办法做到这一点? (下面是示例)

Is there a way to do this? (example bellow)

// action/types.js
import { REHYDRATE } from 'redux-persist/constants'

export type FooBar = {
  foo: number,
  bar: string,
};

export type Action
  = { type: 'FETCH_REQUEST', data: FooBar[] }
  | { type: REHYDRATE, payload: any } // <== this do not work
  ;

// reducer.js
import { REHYDRATE } from 'redux-persist/constants'

export default function (state: State = initialState, action: Action) 
    switch (action.type) {
    case 'FETCH_REQUEST': 
        // do something with action.data
    case REHYDRATE: { // <= flow says: uncovered code
        // do something with action.payload
    default:
        return state
    }
}

推荐答案

Flow不支持在类型定义中使用包含常量的变量.

Flow does not support to use of variables containing constants in type definitions.

您必须在定义中使用字符串值本身或支持数据类型.

You have to either use the string value itself or a support data type in your definition.

这篇文章是类似的如果您也想对其进行审查，则该问题.

This post was a similar issue if you'd like to review it as well.

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