jpsear

  const nest = (items, id = null, link = 'childId') => {
    return items
      .filter(item => item[link] === id)
      .map(item => ({ ...item, children: nest(items, item._id) }))
  }

jpsear

// Return a new array minus a given item
var a = [1, 2, 3, 4, 5]
var b = a.filter(item => item !== 2) // [1, 3, 4, 5]

// Return true if a value is in an array
var a = [1, 2, 3, 4, 5]
var b = a.some(item => item === 1) // true
var b = a.some(item => item === 6) // false

// Return the full item if a value is in an array