Redux - concat不工作

Question

我有模型Language，Entities，EntitiesInfo

export interface Language
{
 name:string;
 status:string;
 id:number;
}

export interface Entities {
  languages?:Language[];
}

export interface EntitiesInfo {
  language?:Language;
}

以下是我的addEntityAction

export const ADD_ENTITY = 'Add Entity';

export interface AddEntityAction extends Action {
  entity:string;
  data:EntitiesInfo;
}
export const addEntity:ActionCreator<AddEntityAction> = (entity:string,data:EntitiesInfo):AddEntityAction => {
  return {
    type:ADD_ENTITY,
    entity:entity,
    data:data
  }
}

这是我的州和减速机：

export interface EntityState {
  entitiesList:Entities;
  entitiesInfo?:EntitiesInfo;
}

const initialState:EntityState = {
  entitiesList:null,
  entitiesInfo:null
}

export const EntityReducer = function (state:EntityState = initialState,action:Action):EntityState{
  switch(action.type)
  {

    case EntityActions.ADD_ENTITY:
      const infoAdd = (<EntityActions.AddEntityAction>action);
      switch(infoAdd.entity)
      {
        case "language":
          state.entitiesList.languages = state.entitiesList.languages.concat(infoAdd.data.language);//this not working

          return {entitiesList:state.entitiesList};
      }


    default:
      return state;
  }


}

我的示例发送：

this.entity = ["language":{"id":100,"name":"English","status":"Active"}]
this.store.dispatch(EntityActions.addEntity("language",this.entity))

我的getState()

语言英语不会合并到state.entitiesList.languages数组中。