add-prop-to-array-of-objects-recursive.js

const addPropToArrayOfObjectsRecursive = (prop, value, array, result = {}) =>
  array.reduce((accum, object, index) =>
    Object.hasOwnProperty.call(object, 'children') ? [
      ...accum,
      {
        ...object,
        [prop]: value,
        children: addPropToArrayOfObjectsRecursive(
          prop, value, object.children, accum
        )
      }
    ] :
    [
      ...accum,
      {
        ...object,
        [prop]: value
      }
    ], result)

const data = [{
    name: "apple",
    children: [{
      name: "apple-child-1",
      children: [{
        name: "apple-grandchild"
      }]
    }]
  },
  {
    name: "orange"
  }
]

console.log((addPropToArrayOfObjectsRecursive('active', false, data)))