浏览器控制台始终显示index.js：21

Question

这是Vue或我不确定的Bootstrap中的错误

我正在使用 Vue 和 Laravel 开发。登录浏览器控制台时，浏览器始终显示 console.log 的位置在index.js:21中。

当我单击index.js时，它将带我到这个地方：

import $ from 'jquery'
import Alert from './alert'
import Button from './button'
import Carousel from './carousel'
import Collapse from './collapse'
import Dropdown from './dropdown'
import Modal from './modal'
import Popover from './popover'
import Scrollspy from './scrollspy'
import Tab from './tab'
import Tooltip from './tooltip'
import Util from './util'

/**
 * --------------------------------------------------------------------------
 * Bootstrap (v4.1.3): index.js
 * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
 * --------------------------------------------------------------------------
 */

(($) => {
  if (typeof $ === 'undefined') {
    throw new TypeError('Bootstrap\'s JavaScript requires jQuery. jQuery must be included before Bootstrap\'s JavaScript.')
  }

  const version = $.fn.jquery.split(' ')[0].split('.')
  const minMajor = 1
  const ltMajor = 2
  const minMinor = 9
  const minPatch = 1
  const maxMajor = 4

  if (version[0] < ltMajor && version[1] < minMinor || version[0] === minMajor && version[1] === minMinor && version[2] < minPatch || version[0] >= maxMajor) {
    throw new Error('Bootstrap\'s JavaScript requires at least jQuery v1.9.1 but less than v4.0.0')
  }
})($)

export {
  Util,
  Alert,
  Button,
  Carousel,
  Collapse,
  Dropdown,
  Modal,
  Popover,
  Scrollspy,
  Tab,
  Tooltip
}

浏览器在下划线加下划线“（”（％）=> { 下划线部分放在字符串文字中

(($) => {
  if (typeof $ === 'undefined') {
    throw new TypeError('Bootstrap\'s JavaScript requires jQuery. jQuery must be included before Bootstrap\'s JavaScript.')
  }

A snapshot of the bug

The browser underlining. I think the issue happens there