.state([key]) => Any
Returns the state hash for the root node of the wrapper. Optionally pass in a prop name and it will return just that value.
Arguments
key(String[optional]): If provided, the return value will be thethis.state[key]of the root component instance.
Example
const wrapper = shallow(<MyComponent />);
expect(wrapper.state().foo).to.equal(10);
expect(wrapper.state('foo')).to.equal(10);