Build a object tree (parent/children) given an object array of type T, the object ID key (elementKey) and the object parent key (parentKey)

BuildTree.ts

type TreeItem<T> = T & { children: TreeItem<T>[] };

export default function buildTree<T>(array: T[], elementKey: keyof T, parentKey: keyof T): TreeItem<T>[] {
  let tree = [] as TreeItem<T>[];
  for (let i = 0; i < array.length; i++) {
    if (array[i][parentKey]) {
      let parent = array.filter(elem => elem[elementKey] === array[i][parentKey]).pop() as TreeItem<T>;
      if (!parent['children']) {
        parent.children = [];
      }
      parent.children.push(array[i] as TreeItem<T>)
    } else {
      tree.push(array[i] as TreeItem<T>);
    }
  }
  return tree;
}

Big thanks! ❤️

Many thanks!

Can we modify it so that we can pass a param for how many levels we want starting from a specific ID?
Suppose our dataset can go upto 10 levels but we want to build a tree of only 3 levels starting from an ID that is on level 5.
e.g: We want 3 levels from a specific ID that is on level 5 so that our final tree will only have level 5 (specific ID), 6, 7 and 8