Function that parses a flat tree structure with "parentId" and "order" to a strutcured data tree with "children"

parse-tree.js

const traverse = (arr, parentId) =>
    arr.filter(node => node.parentId === parentId)
    .reduce((result, current) => [
        ...result,
        {
            ...current,
            children: traverse(arr, current.id)
        }
    ], [])

 const parseTree = (arr) =>
    arr.sort(({ order }) => order)
    .filter(({ parentId }) => !parentId)
    .map(node => ({
        ...node,
        children: traverse(arr, node.id)
    }))
 
 // parseTree(data)