redux-toolkit action not triggered in reducer

Question

I'm trying to trigger a simple action using @reduxjs/Toolkit but it's not working.

I see that the action is dispatched but it's like the slice reducer is not listening to it or something.

const say = createAction("ui/say", what => ({ payload: what }));

const uiSlice = createSlice({
  name: "ui",
  initialState: { said: "" },
  reducers: {
    [say.type]: (state, action) => {
      console.log("saying", action.payload); //<-- not showing, why?
      state.currentList = action.payload;
    }
  }
});

const store = configureStore({
  reducer: combineReducers({
    ui: uiSlice.reducer
  })
});

const Chat = () => {
  const dispatch = useDispatch();
  const [whatToSay, setWhatToSay] = useState("");
  const whatWasSaid = useSelector(state => state.ui.said);

  const onSubmit = e => {
    e.preventDefault();
    dispatch(say(whatToSay));
    setWhatToSay("");
  };

  return (
    <div>
      <form onSubmit={onSubmit}>
        <input type="text" onChange={e => setWhatToSay(e.target.value)} />
        <button>Say</button>
      </form>
      {whatWasSaid ? <p>You said: {whatWasSaid}</p> : <p>Say something</p>}
    </div>
  );
};

Here's a minimal reproducing example: https://codesandbox.io/s/redux-toolkit-0tzxs?file=/src/index.js

Answer 1

I think you mismatched the createSlice API.

From your code, you trying to implement a listener for an action, so you might want to use extraReducers instead:

const uiSlice = createSlice({
  name: "ui",
  initialState: { said: "" },
  // Not reducers: {}
  extraReducers: {
    [say.type]: (state, action) => {
      console.log("saying", action.payload);
      state.currentList = action.payload;
    }
  }
});

Note the reducers prop of createSlice API:

reducers: Object<string, ReducerFunction | ReducerAndPrepareObject>

If you want to use say in reducers it should be:

const say = (state, payload) => {
  console.log("saying", payload);
  state.currentList = payload;
};


const uiSlice = createSlice({
  name: "ui",
  initialState: { said: "" },
  reducers: { say }
});

// Usage
dispatch(uiSlice.actions.say(whatToSay));

@markerikson: with createSlice, the reducers field is for defining reducers and generating actions that will match those reducers. The extraReducers field is for handling actions that were already defined elsewhere.