Flowtype question: passing < types > to react component (when?)

[stevenjmarsh]

In what cases do you pass types to a react component, i.e.

class LocationsMap extends PureComponent<void, ILocationsMapProps, void> {
   ...
}

vs. just setting props in the class

class LocationsMap extends PureComponent {
   props: ILocationsMapProps;
   ...
}

also, go over an appropriate use example for defaultProps

see flow recipes here

[stevenjmarsh]

I tested both scenarios. both work. when? why?

type ILocationsMapProps = {
   ...
};

class LocationsMap extends PureComponent {
// OR
class LocationsMap extends PureComponent<any, ILocationsMapProps, any> {
   props: ILocationsMapProps;
   ...
}