setStatePromise

setStatePromise.js

export function setStatePromise<S, C extends Component>(
    component: C, state: Partial<S>): Promise<void> {
  return new Promise((resolve, _) => {
    component.setState(state, () => {
      resolve();
    });
  });
}

You would call it like this:

return setStatePromise(this, {
    somethingInState: 'You thought I was going to say Hello World'
}).then(() => {
 /* state has actually been updated, do something that needs to use new state */
});