Redux Toolkit createSlice hoạt động thế nào?

createSlice kết hợp action creators + reducer trong cùng một file, dùng Immer nên có thể mutate state trực tiếp.

const userSlice = createSlice({
  name: 'user',
  initialState,
  reducers: {
    setUser(state, action) { state.name = action.payload; }
  }
});
export const { setUser } = userSlice.actions;
export default userSlice.reducer;

createSlice combines action creators and a reducer in one place: createSlice({ name: 'user', initialState, reducers: { setUser(state, action) { state.name = action.payload } } }).

It auto-generates action type strings, uses Immer under the hood so you can write mutating-style updates, and exports both action creators and the reducer.