custom array sort, by field path and weighted values (JavaScript)

sort-by.js

function getVal(obj, fields) {
  if (!(obj && fields[0])) return obj
  return getVal(obj[fields.shift()], fields)
}

export const customSort = (field, byVals) => {
  let sorter
  if (byVals) {
    const sortByWeight = {}
    byVals.forEach((val, weight) => {
      sortByWeight[val] = weight
    })
    sorter = (a, b) => sortByWeight[a] - sortByWeight[b]
  } else {
    sorter = (a, b) => a > b ? 1 : -1
  }

  return (arr) => arr.sort((a, b) => sorter(
    getVal(a, field.split('.')),
    getVal(b, field.split('.'))
  ))
}

///////

const arr = [
  {id:1, title: 'Job A', status: 'done', tags: { flower: true }},
  {id:2, title: 'Job B', status: 'inProgress', tags: { flower: false }},
  {id:3, title: 'Job C', status: 'todo', tags: { flower: true }},
  {id:4, title: 'Job D', status: 'inProgress', tags: { flower: false }},
  {id:5, title: 'Job E', status: 'todo', tags: { flower: false }}
]

let sortField = 'status'
console.log(customSort(sortField)(arr)) // natural sort order
let sortByVals = ['inProgress', 'todo', 'done']
console.log(customSort(sortField, sortByVals)(arr)) // weighted sort order

sortField = 'tags.flower' // dot path
console.log(customSort(sortField)(arr)) // natural sort order
sortByVals = [true, false]
console.log(customSort(sortField, sortByVals)(arr)) // weighted sort order