node_modules/loupe/lib/map.js

import { inspectList } from './helpers'

function inspectMapEntry([key, value], options) {
  options.truncate -= 4
  key = options.inspect(key, options)
  options.truncate -= key.length
  value = options.inspect(value, options)
  return `${key} => ${value}`
}

// IE11 doesn't support `map.entries()`
function mapToEntries(map) {
  const entries = []
  map.forEach((value, key) => {
    entries.push([key, value])
  })
  return entries
}

export default function inspectMap(map, options) {
  const size = map.size - 1
  if (size <= 0) {
    return 'Map{}'
  }
  options.truncate -= 7
  return `Map{ ${inspectList(mapToEntries(map), options, inspectMapEntry)} }`
}