react-focus-lock/dist/es2015/clientSideEffect.js

It is a trap! (for a focus)

import React, { useEffect, useRef } from 'react';
function withSideEffect(reducePropsToState, handleStateChangeOnClient) {
  if (process.env.NODE_ENV !== 'production') {
    if (typeof reducePropsToState !== 'function') {
      throw new Error('Expected reducePropsToState to be a function.');
    }
    if (typeof handleStateChangeOnClient !== 'function') {
      throw new Error('Expected handleStateChangeOnClient to be a function.');
    }
  }
  return function wrap(WrappedComponent) {
    if (process.env.NODE_ENV !== 'production') {
      if (typeof WrappedComponent !== 'function') {
        throw new Error('Expected WrappedComponent to be a React component.');
      }
    }
    var mountedInstances = [];
    function emitChange() {
      console.log('emitting');
      var state = reducePropsToState(mountedInstances.map(function (instance) {
        return instance.current;
      }));
      handleStateChangeOnClient(state);
    }
    var SideEffect = function SideEffect(props) {
      var lastProps = useRef(props);
      useEffect(function () {
        lastProps.current = props;
      });
      useEffect(function () {
        console.log('ins added');
        mountedInstances.push(lastProps);
        return function () {
          console.log('ins removed');
          var index = mountedInstances.indexOf(lastProps);
          mountedInstances.splice(index, 1);
        };
      }, []);
      return /*#__PURE__*/React.createElement(WrappedComponent, props);
    };
    return SideEffect;
  };
}
export default withSideEffect;