@atlaskit/tree/dist/es2019/utils/path.js

A React Component for displaying expandable and sortable tree hierarchies

/*
  Checking if two given path are equal
 */
export const isSamePath = (a, b) => {
  if (a === b) {
    return true;
  }
  return a.length === b.length && a.every((v, i) => v === b[i]);
};

/*
  Checks if the two paths have the same parent
 */
export const hasSameParent = (a, b) => isSamePath(getParentPath(a), getParentPath(b));

/*
  Calculates the parent path for a path
*/
export const getParentPath = child => child.slice(0, child.length - 1);

/*
  It checks if the item is on top of a sub tree based on the two neighboring items, which are above or below the item.
*/
export const isTopOfSubtree = (belowPath, abovePath) => !abovePath || isParentOf(abovePath, belowPath);
const isParentOf = (parent, child) => isSamePath(parent, getParentPath(child));
export const getIndexAmongSiblings = path => {
  const lastIndex = path[path.length - 1];
  return lastIndex;
};
export const getPathOnLevel = (path, level) => path.slice(0, level);
export const moveAfterPath = (after, from) => {
  const newPath = [...after];
  const movedDownOnTheSameLevel = isLowerSibling(newPath, from);
  if (!movedDownOnTheSameLevel) {
    // not moved within the same subtree
    newPath[newPath.length - 1] += 1;
  }
  return newPath;
};
export const isLowerSibling = (a, other) => hasSameParent(a, other) && getIndexAmongSiblings(a) > getIndexAmongSiblings(other);