npm install validator -D

const Validator = require('validator');

const isEmpty = require('./is-empty');

module.exports = function validateRegisterInput(data) {

  let errors = {};

  if (!Validator.isLength(data.name, { min: 2, max: 30 })) {

    errors.name = '名字的长度不能小于2位且不能超过30位';

  }

  return {

    errors,

    isValid: isEmpty(errors)

  }

}

const isEmpty = value => {

  return (

    value == undefined ||

    value === null ||

    (typeof value === 'object' && Object.keys(value).length === 0) ||

    (typeof value === 'string' && value.trim().length === 0)

  );

};

module.exports = isEmpty;

// 引入 input 验证密码

const validateRegisterInput = require('../../validation/register');

...

const { errors, isValid } = validateRegisterInput(ctx.request.body);

// 判断是否验证通过

if (!isValid) {

  ctx.status = 400;

  ctx.body = errors;

  return;

}