Typescript 使用redux thunk键入安全使用调度
我正在使用Typescript 使用redux thunk键入安全使用调度,typescript,redux,redux-thunk,Typescript,Redux,Redux Thunk,我正在使用redux-thunk来使用异步动作生成器。结果也会返回给相应的调用者 function fetchUserName(userId: number): Promise<string> { return Promise.resolve(`User ${userId}`) } function requestUserName(userId: number) { return (dispatch: Dispatch) => { return fetchUs
redux-thunk
来使用异步动作生成器。结果也会返回给相应的调用者
function fetchUserName(userId: number): Promise<string> {
return Promise.resolve(`User ${userId}`)
}
function requestUserName(userId: number) {
return (dispatch: Dispatch) => {
return fetchUserName(userId).then(name => {
dispatch({
type: 'SET_USERNAME',
payload: name,
})
})
}
}
这正按预期工作,但由于类型无效,TypeScript不会编译它
useDispatch
返回的dispatch
未被识别为返回承诺的函数,因此TypeScript认为属性“then”在type上不存在(dispatch:dispatch)=>Promise.
useDispatch
周围创建一个包装器,或者重新定义dispatch
的类型,但我不知道在这种特殊情况下该类型应该是什么样子
非常感谢您的建议。
useDispatch
返回Dispatch
类型,因此您只能使用它发送标准操作。要同时分派thunk操作,请将其类型声明为(fromredux thunk
)
ThunkDispatch
接收门店状态的类型参数以及您的操作类型。它允许发送一个,这基本上是requestUserName
的内部功能
例如,可以按如下方式键入:
import { ThunkDispatch } from "redux-thunk";
import { AnyAction } from "redux";
type State = { a: string }; // your state type
type AppDispatch = ThunkDispatch<State, any, AnyAction>;
// or restrict to specific actions instead of AnyAction
function User() {
const dispatch: AppDispatch = useDispatch();
useEffect(() => {
dispatch(requestUserName(1))
.then(...) // works now
}, []);
...
}
import { ThunkDispatch } from "redux-thunk";
import { AnyAction } from "redux";
type State = { a: string }; // your state type
type AppDispatch = ThunkDispatch<State, any, AnyAction>;
// or restrict to specific actions instead of AnyAction
function User() {
const dispatch: AppDispatch = useDispatch();
useEffect(() => {
dispatch(requestUserName(1))
.then(...) // works now
}, []);
...
}
import thunk, { ThunkDispatch, ThunkMiddleware } from "redux-thunk";
const mw: ThunkMiddleware<State, AnyAction> = thunk;
const dummyReducer = (s: State | undefined, a: AnyAction) => ({} as State);
const store = createStore(dummyReducer, applyMiddleware(mw));
type AppDispatch = typeof store.dispatch // <-- get the type from store