code: function convertUnit(str) {
    const reg = /\.\d*/;
    const result = reg.exec(str);
    if (result && result[0]) {
      return {
        precision: result[0].length - 1,
        unit: str.substring(result[0].length + 1),
      };
    }
    return {
      unit: str,
    };
  }
docs: Convert the unit info
  @param {String} str The unit info
  @returns {Object} The format unit info