React/enzyme: Accessing a prop value from another prop

I have a ES5 react class that looks like the following:

const Notice = React.createClass<{id: string}>({

  noticeName: 'prefx_' +,

  // ...more code

When I try to mock it:

notice = mount(<Notice {id: 'test'} />).instance();
console.log(notice.noticeName) // prints prefix_undefined
expect(notice.noticeName).toBe('prefix_test'); // error

The noticeName prop won't use the id I passed into the mock. How can I make it work so that the expect statement would pass?