问题如下

解决办法

StackOverflow Error TS2339: Property 'Connection' does not exist on type 'Navigator'

图示

export type Navigator = NavigatorNetworkInformation
export declare interface NavigatorNetworkInformation {
  readonly connection?: NetworkInformation
}
type Megabit = number
type Millisecond = number
export type EffectiveConnectionType =  '2g' | '3g' | '4g' | 'slow-2g' | 'unknown'
export type ConnectionType =
  | 'bluetooth'
  | 'cellular'
  | 'ethernet'
  | 'mixed'
  | 'none'
  | 'other'
  | 'unknown'
  | 'wifi'
  | 'wimax'
export interface NetworkInformation extends EventTarget {
  readonly type?: ConnectionType
  readonly effectiveType?: EffectiveConnectionType
  readonly downlinkMax?: Megabit
  readonly downlink?: Megabit
  readonly rtt?: Millisecond
  readonly saveData?: boolean
  onchange?: EventListener
}

使用示例

/**
 * 取得网络类型
 */
export function getNetworkType() :string {
  /* wired 有线
    bluetooth,
    wifi,
    2g,3g,4g,5g...,
    unkown
  */
  const ua = navigator.userAgent;
  const ut = (navigator as Navigator).connection as NetworkInformation;
  let utt = ut ? ut.type ? ut.type.toLowerCase() : ut.effectiveType.toLowerCase() : null;
  if(utt){
    switch (utt) {//bluetooth,
      case 'cellular':
      case 'wimax':
        utt = ut ? ut.effectiveType ? ut.effectiveType.toLowerCase() : null : null;
        break;
      case 'wifi':
        break;
      case 'ethernet':
        utt = 'wired';
        break
      case 'none':
      case 'other':
      case 'unknown':
        utt = null;
        break
      default:
        break;
    }
  }
  let networkStr = utt ? utt : ua.match(/NetType\/\w+/) ? ua.match(/NetType\/\w+/)[0] : 'unknown';
  networkStr = networkStr.toLowerCase().replace('nettype/', '');

  return networkStr ? networkStr === '3gnet' ? '3g' : networkStr : 'unknown';
}