NGRX reducer approach TS

user.reducer.ts

import { Action } from '@ngrx/store';
import { IUser } from './user.model';

export namespace UserActions {
  export enum ActionTypes {
    GET_USER_REQUEST = '[Welcome] Get User Request',
    GET_USER_FAILURE = '[Welcome] Get User Failure',
    GET_USER_SUCCESS = '[Welcome] Get User Success',
  }

  export class GetUserRequestAction implements Action {
    public readonly type = ActionTypes.GET_USER_REQUEST;

    constructor(public payload: {
      userId: number,
    }) { }
  }

  export class GetUserFailureAction implements Action {
    public readonly type = ActionTypes.GET_USER_FAILURE;
    constructor(public payload: {
      error: string,
    }) { }
  }

  export class GetUserSuccessAction implements Action {
    public readonly type = ActionTypes.GET_USER_SUCCESS;
    constructor(public payload: {
      user: IUser
    }) { }
  }

  export type Actions =
    GetUserRequestAction |
    GetUserFailureAction |
    GetUserSuccessAction
    ;
}