text: /**
   * Created by PanJiaChen on 16/11/18.
   */
  
  /**
   * @param {string} path
   * @returns {Boolean}
   */
  export function isExternal(path) {
    return /^(https?:|mailto:|tel:)/.test(path)
  }
  
  /**
   * @param {string} str
   * @returns {Boolean}
   */
  export function validUsername(str) {
    const valid_map = /^[a-zA-Z0-9_-]{4,16}$/;
    return valid_map.test(str)
  }
  