Function mountState

docs/external/js/react-dom.development.js:15352–15369

(initialState)

  }

  function mountState(initialState) {
    var hook = mountWorkInProgressHook();

    if (typeof initialState === 'function') {
      // $FlowFixMe: Flow doesn't like mixed types
      initialState = initialState();
    }

    hook.memoizedState = hook.baseState = initialState;
    var queue = hook.queue = {
      pending: null,
      dispatch: null,
      lastRenderedReducer: basicStateReducer,
      lastRenderedState: initialState
    };
    var dispatch = queue.dispatch = dispatchAction.bind(null, currentlyRenderingFiber$1, queue);
    return [hook.memoizedState, dispatch];
  }

  function updateState(initialState) {
    return updateReducer(basicStateReducer);