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    2.10.1 • Public • Published

    TypeScript FSA utilities for redux-thunk

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    NOTE: There's breaking changes from 1.x. Read on to find out more and check the notes at the bottom for more info


    npm install typescript-fsa-redux-thunk redux redux-thunk


    thunkToAction(ThunkActionCreator): ((Params) => Result)

    Another useful cast function that can help when attempting to extract the return value out of your async action creator. If the action is being pre-bound to dispatch, then all we want back is the return value (the action object). Coming soon: an example. TL;DR: pass your async action creator into this before passing it to bindActionCreators or the mapDispatchToProps object (react-redux).

    asyncFactory<State>(ActionCreatorFactory): ((type: string, AsyncWorker) => ({ (params?): ThunkActionCreator, async: AsyncActionCreators }))

    Factory function to easily create a typescript-fsa redux thunk.


    import 'isomorphic-fetch';
    import { createStore, applyMiddleware, AnyAction } from 'redux';
    import thunkMiddleware, { ThunkMiddleware } from 'redux-thunk';
    import { reducerWithInitialState } from 'typescript-fsa-reducers';
    import actionCreatorFactory from 'typescript-fsa';
    import { asyncFactory } from 'typescript-fsa-redux-thunk';
    /** You can optionally use custom Error types */
    class CustomError extends Error {}
    /** Parameters used for logging in */
    interface LoginParams {
      email: string;
      password: string;
    /** The object that comes back from the server on successful login */
    interface UserToken {
      token: string;
    /** The shape of our Redux store's state */
    interface State {
      title: string;
      userToken: UserToken;
      loggingIn?: boolean;
      error?: CustomError;
    /** The typescript-fsa action creator factory function */
    const create = actionCreatorFactory('examples');
    /** The typescript-fsa-redux-thunk async action creator factory function */
    const createAsync = asyncFactory<State>(create);
    /** Normal synchronous action */
    const changeTitle = create<string>('Change the title');
    /** The asynchronous login action; Error type is optional */
    const login = createAsync<LoginParams, UserToken, CustomError>(
      async (params, dispatch) => {
        const url = ``;
        const options: RequestInit = {
          method: 'POST',
          body: JSON.stringify(params),
          headers: {
            'Content-Type': 'application/json; charset=utf-8',
        const res = await fetch(url, options);
        if (!res.ok) {
          throw new CustomError(`Error ${res.status}${res.statusText}`);
        dispatch(changeTitle('You are logged-in'));
        return res.json();
    /** An initial value for the application state */
    const initial: State = {
      title: 'Please login',
      userToken: {
        token: '',
    /** Reducer, handling updates to indicate logging-in status/error */
    const reducer = reducerWithInitialState(initial)
      .case(changeTitle, (state, title) => ({
      .case(login.async.started, (state) => ({
        loggingIn: true,
        error: undefined,
      .case(login.async.failed, (state, { error }) => ({
        loggingIn: false,
      .case(login.async.done, (state, { result: userToken }) => ({
        loggingIn: false,
        error: undefined,
    /** Putting it all together */
    (async () => {
      // Declaring the type of the redux-thunk middleware is what makes
      // `store.dispatch` work. (redux@4.x, redux-thunk@2.3.x)
      const thunk: ThunkMiddleware<State, AnyAction> = thunkMiddleware;
      const store = createStore(reducer, applyMiddleware(thunk));
      try {
        // See for valid users on this site
        await store.dispatch(
            email: '',
            password: 'cityslicka',
        const { title, userToken } = store.getState();
        console.log(title, userToken);
      } catch (err) {

    Note: A change from 1.x is the result type is not always assumed to be a Promise. If you want the result to be a promise, just return one from your worker function; but continue to specify the result as T rather than Promise<T> (same as 1.x).

    The API has been simplified. This release is in preparation for a new project that works with react hooks. Coming soon!

    react-redux integrated

    import { ThunkDispatch, AnyAction } from 'redux-thunk';
    import { RootState } from 'to/your/reducers';
    declare module 'react-redux' {
      interface DefaultRootState extends RootState {}
      function useDispatch(): ThunkDispatch<RootState, never, AnyAction>;
    declare module 'typescript-fsa-redux-thunk' {
      interface DefaultRootState extends RootState {}


    npm i typescript-fsa-redux-thunk

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