打字稿：如何在 Redux 中键入 Dispatch

Question

例如我想删除dispatch: any这里：

export const fetchAllAssets = () => (dispatch: any) => {
  dispatch(actionGetAllAssets);
  return fetchAll([getPrices(), getAvailableSupply()]).then((responses) =>
    dispatch(actionSetAllAssets(formatAssets(responses))));
}

我在上面发送了 2 个操作，actionsGetAllAssets并且actionsSetAllassets.

以下是两者的接口和 actionCreators：

// Interfaces
interface IActions {
  GET_ALL_ASSETS: string;
  SET_ALL_ASSETS: string;
  GET_MARKET_PRICES: string;
  SET_MARKET_PRICES: string;
  ADD_COIN_PORTFOLIO: string;
  ADD_COINS_PORTFOLIO: string;
  UPDATE_COIN_PORTFOLIO: string;
  REMOVE_COIN_PORTFOLIO: string;
} 

interface IGetAllAssets {
  type: IActions['GET_ALL_ASSETS'];
  loading: boolean;
}

interface ISetAllAssets {
  type: IActions['SET_ALL_ASSETS'];
  assets: IAsset[];
  loading: boolean;
}

// ACTION CREATORS
const actionGetAllAssets = () => ({
  type: Actions.GET_ALL_ASSETS,
  loading: true
});

const actionSetAllAssets = (data: any) => ({
  type: Actions.SET_ALL_ASSETS,
  assets: data,
  loading: false
});

然后我尝试了以下方法：

export const fetchAllAssets = () => (dispatch: IGetAllAssets | ISetAllAssets) => {
  console.log('fetchAllAssets', dispatch);
  dispatch(actionGetAllAssets);
  return fetchAll([getPrices(), getAvailableSupply()]).then((responses) =>
    dispatch(actionSetAllAssets(formatAssets(responses))));
}

但是它会产生这个 Typescript 错误：

无法调用类型缺少调用签名的表达式。输入'IGetAllAssets | ISetAllAssets' 没有兼容的调用 signatures.ts(2349)

想法？或者是否有不同的方式来输入调度事件？

Answer 1

ReduxDispatch<A>类型具有您可以使用的通用类型，其中A是操作类型。

export const fetchAllAssets = () => (dispatch: Dispatch<IGetAllAssets | ISetAllAssets>) => {
  // ...
}

Answer 2

我又有点远了！

调度是一个事件函数，所以让它工作：

interface IAllAssets {
  type: IActions['GET_ALL_ASSETS'];
  assets?: IAsset[];
  loading: boolean;
}

// ACTIONS
// Fetch assets from Nomics API V1.
export const fetchAllAssets = () => (dispatch: (arg: IAllAssets) => (IAllAssets)) =>
{
   dispatch(actionGetAllAssets());
   return fetchAll([getPrices(), getAvailableSupply()]).then((responses) =>
       dispatch(actionSetAllAssets(formatAssets(responses))));
}

不过我仍然想创建一个dispatch type类似的东西：

interface IAllAssetsDispatch {
  dispatch: (arg: IAllAssets) => (IAllAssets)
}

export const fetchAllAssets = () => (dispatch: IAllAssetsDispatch) => {

但这同样会产生缺少调用签名的错误。

知道了！

忘记了type我需要使用它而不是interface函数：

type DispatchAllAssets = (arg: IAllAssets) => (IAllAssets);

type DispatchMarketPrices = (arg: ISetMarket) => (ISetMarket);

type DispatchAddCoin = (arg: ICoinPortfolio) => (ICoinPortfolio);

type DispatchAddCoins = (arg: ICoinsPortfolio) => (ICoinsPortfolio);

// ACTIONS
// Fetch assets from Nomics API V1.
export const fetchAllAssets = () => (dispatch: DispatchAllAssets) => {
  dispatch(actionGetAllAssets());
  return fetchAll([getPrices(), getAvailableSupply()]).then((responses) =>
    dispatch(actionSetAllAssets(formatAssets(responses))));
}

// Fetch USD, USDC & USDT markets to filter out Exchange List.
export const fetchMarketPrices = (asset: string) => (dispatch: DispatchMarketPrices) => {
  dispatch(actionGetMarketPrices);
  return getMarkets().then((res) => {
    if (res && res.marketUSD && res.marketUSDC && res.marketUSDT) {
      const exchangesForAsset = combineExchangeData(asset, res);
      return dispatch(actionSetMarketPrices(exchangesForAsset));
    }
    else {
      return dispatch(actionSetMarketPrices([]));
    }
  });
}