text: "use strict";
  
  Object.defineProperty(exports, "__esModule", {
    value: true
  });
  exports.findExpandedKeys = findExpandedKeys;
  exports.getExpandRange = getExpandRange;
  
  function findExpandedKeys() {
    var prev = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];
    var next = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : [];
    var prevLen = prev.length;
    var nextLen = next.length;
  
    if (Math.abs(prevLen - nextLen) !== 1) {
      return {
        add: false,
        key: null
      };
    }
  
    function find(shorter, longer) {
      var cache = new Map();
      shorter.forEach(function (key) {
        cache.set(key, true);
      });
      var keys = longer.filter(function (key) {
        return !cache.has(key);
      });
      return keys.length === 1 ? keys[0] : null;
    }
  
    if (prevLen < nextLen) {
      return {
        add: true,
        key: find(prev, next)
      };
    }
  
    return {
      add: false,
      key: find(next, prev)
    };
  }
  
  function getExpandRange(shorter, longer, key) {
    var shorterStartIndex = shorter.findIndex(function (data) {
      return data.key === key;
    });
    var shorterEndNode = shorter[shorterStartIndex + 1];
    var longerStartIndex = longer.findIndex(function (data) {
      return data.key === key;
    });
  
    if (shorterEndNode) {
      var longerEndIndex = longer.findIndex(function (data) {
        return data.key === shorterEndNode.key;
      });
      return longer.slice(longerStartIndex + 1, longerEndIndex);
    }
  
    return longer.slice(longerStartIndex + 1);
  }