json_schema： 用于是描述你的JSON数据和规范格式
网站： http://json-schema.org/
不需要安装

ajv： 是JSON Schema的验证工具
网站： https://ajv.js.org/
安装：

yarn add ajv -S
yarn add ajv-errors -S
yarn add ajv-i18n -S
yarn add ajv-formats -S

如果上面代码报错，请执行下2句：

npm config set registry https://registry.npm.taobao.org
npm config set disturl https://npm.taobao.org/dist

简单示例代码

const Ajv = require('ajv')
const localize = require('ajv-i18n')  //中文

//pets会警告，因为它定义了不受约束的元组。
//要定义一个正好包含 2 个元素的元组， 需minItems:2,additionalItems: false
const schema = {
  type: 'object',
  properties: {
    name: {
      type: 'string'
    },
    age: {
      type: 'number',
    },
    pets: {
      type: 'array',
      items: [
        {
          type: 'string',
        },
        {
          type: 'number',
        }
      ],      
      // minItems:2,      
      // additionalItems: false
    }
  },
  required: ['name', 'age']
}

const ajv = new Ajv() 
const validate = ajv.compile(schema)
const valid = validate({
  name: 'haha',
  age: "18a",
  pets: ['mimi', 12]
})
if (!valid) { 
  localize.zh(validate.errors)  //将报错信息转为中文
  console.log(validate.errors)
}

format

内置format和自定义format

const Ajv = require("ajv")
const localize = require('ajv-i18n') 
const addFormats = require("ajv-formats")  //**引入**
const ajv = new Ajv() 
addFormats(ajv)

const schema = {
  type: 'object',
  properties: {
    name: {
      type: 'string',
      format:'email'  //***内置****
    },
    age: {  
      type: "number",
      format:'qy'  //****自定义***
    }
  },
  required: ['name']
}
 
//自定义 
ajv.addFormat("qy", {
  type: "number",
  validate: (x)=>{
    return x>5?true:false
  }
})

const validate = ajv.compile(schema)
const valid = validate({
  name: 'haha@qq.com',
  age:1
})
if (!valid) { 
  localize.zh(validate.errors)  //将报错信息转为中文
  console.log(validate.errors)
}

关键字

关键字是3种类型
1、 "validate" function
2、 "compile" function
3、 "macro" function

const Ajv = require("ajv")
const localize = require('ajv-i18n')  //中文 
const ajv = new Ajv()  

const schema = {
  type: 'object',
  properties: {
    name: {
      type: 'string',
      test3: false
    } 
  },
  required: ['name']
}
 
// validate类型  
ajv.addKeyword('test1', {
  validate(schema, data) {
    console.log("普通：",schema, data)
    if (schema === true) return true
    else return data.length === 6
  },
})

// compile类型
ajv.addKeyword('test2', {
  compile(sch, parentSchema) {
    console.log("compile：",sch, parentSchema) 
    return (x) => {
      if(x.length===6){
        return true
      }else{
        return false
      }
    }
  }
})
// macro型  
ajv.addKeyword('test3', {
  macro() {
    return {
      minLength: 10,
    }
  },
})
const validate = ajv.compile(schema)
const valid = validate({
  name: 'ha12ha'
})
if (!valid) { 
  localize.zh(validate.errors)  //将报错信息转为中文
  console.log(validate.errors)
}

自定义错误

const Ajv = require("ajv").default
const localize = require('ajv-i18n')  //中文 
const ajv = new Ajv({allErrors: true})
require("ajv-errors")(ajv /*, {singleError: true} */)

const schema = {
  type: "object",
  properties: {
    name: {
      type: 'string',
      minLength:10,
      errorMessage: {  //单个属性验证的错误提示
        type:"name必须是string",
        minLength:"name长度不能小于10"
      }
    },
    age: {
      type: 'number'
    },
  },
  required: ['name'],
  //errorMessage: "name或age错误", //这里是统一设置错误，无论是name还是age错，都会报这句
}

const validate = ajv.compile(schema)
const valid = validate({
  name: "abc1221",
  age: 3
})
if (!valid) { 
  console.log(validate.errors)
  console.log("*****************")
  localize.zh(validate.errors)  //将报错信息转为中文
}else{
  console.log("通过")
}