我可以在angular + ngrx中使用对象传播语法吗?

我从此处阅读有关对象传播语法的信息，在尝试在我的项目中使用它时，我的设置如下:

I was reading from here about the object spread syntax and I'm trying to use it in my project, my setup is the following:

• 角2
• angular/cli 1.0.0-rc.0
• ngrx/core 1.2.0
• ngrx/商店2.2.1
• rxjs 5.1.0
• 打字稿2.0.10

在我的reducer.ts中，

In my reducer.ts I have

export interface State {
  [id: number]: string
}

export function reducer(state= {}, action: Action): State {
case 'TEST':
  return {
    ...state,
    2: 'foo'
  }
}

但是我遇到了以下编译错误，我试图找出问题所在:

But I got the following compiling error, I'm trying to figure out what's wrong:

Property assignment expected
Type '{ 2: string; state: State; }' is not assignable to type 'State'
Object literal may only specify known properties, and 'state' does not exist in type 'State'

有什么想法吗?谢谢！