joi库 学习笔记

零、背景


node.js 应用中,req.query / req.body 传来的参数需要做 valication( 合法性验证 )

一、安装


https://github.com/hapijs/joi

npm i joi --save

const Joi = require('Joi');

二、基本用法


Joi.validate(value, schema, [options]);

1、通过验证


这里我们定义了三个字段:name(姓名)、age(年龄)、sex(性别)

router.post('/create', function (req, res, next) {

  const schema = Joi.object().keys({
    name: Joi.string().min(2).max(20).required(),
    age: Joi.number().min(0).max(100).required(),
    sex: Joi.string().valid(['男', '女']),
  })

  const result = Joi.validate({ name: '小明', age: 12, sex: "男" }, schema);

  res.send(result);

});

return:

{
    "error": null,
    "value": {
        "name": "小明",
        "age": 12,
        "sex": "男"
    }
}

总结:

判断 result.error === null 为 true 后,直接拿 result.value

2、不通过验证


代码同上,不同的地方如下:

const result = Joi.validate({ name: '小', age: -1, sex: "跨性别者" }, schema);

return:

{
    "error": {
        "isJoi": true,
        "name": "ValidationError",
        "details": [
            {
                "message": "\"name\" length must be at least 2 characters long",
                "path": [
                    "name"
                ],
                "type": "string.min",
                "context": {
                    "limit": 2,
                    "value": "小",
                    "key": "name",
                    "label": "name"
                }
            }
        ],
        "_object": {
            "name": "小",
            "age": -1,
            "sex": "跨性别者"
        }
    },
    "value": {
        "name": "小",
        "age": -1,
        "sex": "跨性别者"
    }
}

总结:

判断 result.error === null 为 false 后,直接拿 result.error 值。

注 1:哪怕 name、age、sex 三个变量我都传非法值,result.error.details 这个数组也只有一个元素,所以想要打印错误信息,直接取 result.error.details[0].message

注 2:如果想打印出所有的错误信息,改写如下:


 const result = Joi.validate({ name: '小', age: 12, sex: "跨性别者" }, schema, { abortEarly: false }); 

return:

{
    "error": {
        "isJoi": true,
        "name": "ValidationError",
        "details": [
            {
                "message": "\"name\" length must be at least 2 characters long",
                "path": [
                    "name"
                ],
                "type": "string.min",
                "context": {
                    "limit": 2,
                    "value": "小",
                    "key": "name",
                    "label": "name"
                }
            },
            {
                "message": "\"sex\" must be one of [男, 女]",
                "path": [
                    "sex"
                ],
                "type": "any.allowOnly",
                "context": {
                    "value": "跨性别者",
                    "valids": [
                        "男",
                        "女"
                    ],
                    "key": "sex",
                    "label": "sex"
                }
            }
        ],
        "_object": {
            "name": "小",
            "age": 12,
            "sex": "跨性别者"
        }
    },
    "value": {
        "name": "小",
        "age": 12,
        "sex": "跨性别者"
    }
}

三、单独使用


joi 不仅仅作用于 scheme 对象,还可以单独使用。

1、通过验证


  const result = Joi.validate("小明", Joi.string().min(2).max(20).required());

  res.send(result);

return:

{
    "error": null,
    "value": "小明"
}

2、不通过验证


  const result = Joi.validate("小", Joi.string().min(2).max(20).required());

  res.send(result);

return:

{
    "error": {
        "isJoi": true,
        "name": "ValidationError",
        "details": [
            {
                "message": "\"value\" length must be at least 2 characters long",
                "path": [],
                "type": "string.min",
                "context": {
                    "limit": 2,
                    "value": "小",
                    "label": "value"
                }
            }
        ],
        "_object": "小"
    },
    "value": "小"
}

四、验证规则


对一个字段的基本的验证规则是:

类型 / 长度范围 / 取值范围 / 是否必填 / 与其它字段的关系 / 默认值

1、类型


//任意类型
any()

//指定类型
array()
boolean()
binary()
date()
func()
number()
object()
string()

类型下还有子约束,如下面的integer()alphanum()等:

//Requires the number to be an integer (no floating point).
Joi.number().integer(),

//Requires the string value to only contain a-z, A-Z, and 0-9.
Joi.string().alphanum()

Joi.string().regex(/^[a-zA-Z0-9]{3,30}$/),

Joi.string().email()

注1:除了 类型约束 ,其他约束都叫 子约束
注2:先写 类型约束 才能继续“点写” 子约束
注3:类型约束 和 子约束 的适用关系详看:https://github.com/hapijs/joi/blob/v13.4.0/API.md
注4:any() 类型 下的 子约束 可以应用在其它任意类型下

枚举类型可以参考下面的3 - (1)

2、长度范围


min() / max()

Joi.number().min(2)
Joi.array().max(5)

3、取值范围


(1) valid - 白名单

可以用来实现枚举类型

a: Joi.any().valid('a'),
b: Joi.any().valid('b', 'B'),
c: Joi.any().valid(['c', 'C'])

(2) invalid - 黑名单

a: Joi.any().invalid('a'),
b: Joi.any().invalid('b', 'B'),
c: Joi.any().invalid(['c', 'C'])

(3) allow - 白名单的补充

a: Joi.any().allow('a'),
b: Joi.any().allow('b', 'B'),
c: Joi.any().allow(['c', 'C'])

4、是否必填


只对 undefined 有效,null 会认为不合法

Joi.any().required()

代码见下面的6 - (2)

5、与其它字段的关系


(1) with / without / or

如现在有 a、b 两个字段:

 const schema = Joi.object().keys({
    a: Joi.any(),
    b: Joi.any()
}).with('a', 'b');

a.with('a', 'b') //a 和 b 必须都要填写

b.without('a', 'b'); //a 和 b 只能填写其中一个

c.or('a', 'b') //b 和 b 至少填写一个

(2) when

需求:验证条件是男人必须 50-100 岁,女人必须 0-50岁

  const schema = Joi.object().keys({
    name: Joi.string().min(2).max(20).required(),
    age: Joi.number().min(0).max(100).required().when('sex', {
      is: '男',
      then: Joi.number().min(50).max(100),
      otherwise: Joi.number().min(0).max(50),
    }),
    sex: Joi.string().valid(['男', '女']),
  })

  const result = Joi.validate({ name: '小明', age: 60, sex: "女" }, schema);

return:

{
    "error": {
        "isJoi": true,
        "name": "ValidationError",
        "details": [
            {
                "message": "\"age\" must be less than or equal to 50",
                "path": [
                    "age"
                ],
                "type": "number.max",
                "context": {
                    "limit": 50,
                    "value": 60,
                    "key": "age",
                    "label": "age"
                }
            }
        ],
        "_object": {
            "name": "小明",
            "age": 60,
            "sex": "女"
        }
    },
    "value": {
        "name": "小明",
        "age": 60,
        "sex": "女"
    }
}

6、默认值


只对 undefined 有效,null 会认为不合法

(1) 无规则
  const result = Joi.validate(undefined, Joi.string());

return:

{
    "error": null
}

注意:没有 value 值

(2) 加上 required()
  const result = Joi.validate(undefined, Joi.string().required());

return:

{
    "error": {
        "isJoi": true,
        "name": "ValidationError",
        "details": [
            {
                "message": "\"value\" is required",
                "path": [],
                "type": "any.required",
                "context": {
                    "label": "value"
                }
            }
        ]
    }
}
(3) 加上 default()
  const result = Joi.validate(undefined, Joi.string().default("空"));

return:

{
    "error": null,
    "value": "空"
}

五、验证规则的补充


1、对某个字段加上多个约束

验证条件为即可是string值也可是number值:

  const result = Joi.validate(23, [Joi.string(), Joi.number()]);

2、对多余传进来的变量不要理会

下面多传了一个 hometown 字段

  const schema = Joi.object().keys({
    name: Joi.string().min(2).max(20),
    age: Joi.number().min(0).max(100).required(),
    sex: Joi.string().valid(['男', '女']),
  })

  const result = Joi.validate({ name: '小明', age: 12, sex: "男", hometown: "上海" }, schema);

return:

{
    "error": {
        "isJoi": true,
        "name": "ValidationError",
        "details": [
            {
                "message": "\"hometown\" is not allowed",
                "path": [
                    "hometown"
                ],
                "type": "object.allowUnknown",
                "context": {
                    "child": "hometown",
                    "key": "hometown",
                    "label": "hometown"
                }
            }
        ],
        "_object": {
            "name": "小明",
            "age": 12,
            "sex": "男",
            "hometown": "上海"
        }
    },
    "value": {
        "name": "小明",
        "age": 12,
        "sex": "男",
        "hometown": "上海"
    }
}

解决办法:

options 参数加上 { allowUnknown: true }

  const result = Joi.validate({ name: '小明', age: 12, sex: "男", hometown: "上海" }, schema, { allowUnknown: true });

return:

{
    "error": null,
    "value": {
        "name": "小明",
        "age": 12,
        "sex": "男",
        "hometown": "上海"
    }
}

注意:value 里也会保留多传的 hometown 字段

六、坑


1、Jio 自动转数据类型


例一

  const result = Joi.validate("true", Joi.boolean());

return:

{
    "error": null,
    "value": true
}

例二

  const result = Joi.validate("1", Joi.number());

return:

{
    "error": null,
    "value": 1
}

Joi 会在觉得恰当的时候帮你自动转换数据类型使之更容易匹配上规则。但是,这样往往适得其反。

三种方法可以解决这个问题:

(1) 使用 strict() 子约束

拿上文的例一做改造:

  const result = Joi.validate("true", Joi.boolean().strict());

return:

{
    "error": {
        "isJoi": true,
        "name": "ValidationError",
        "details": [
            {
                "message": "\"value\" must be a boolean",
                "path": [],
                "type": "boolean.base",
                "context": {
                    "label": "value"
                }
            }
        ],
        "_object": "true"
    },
    "value": "true"
}
(2) 使用 Joi.extend 扩展 Joi 类

其实原理也是使用 strict() 子约束,但不用显式调用了

    Joi = Joi.extend({
      name: 'boolean',
      base: Joi.boolean().strict()
    });

    const result = Joi.validate("true", Joi.boolean());

return:

{
    "error": {
        "isJoi": true,
        "name": "ValidationError",
        "details": [
            {
                "message": "\"value\" must be a boolean",
                "path": [],
                "type": "boolean.base",
                "context": {
                    "label": "value"
                }
            }
        ],
        "_object": "true"
    },
    "value": "true"
}

[拓展]

如何用 Joi.extend 添加新的 类型约束 去校验手机号?

    Joi = Joi.extend({
      name: 'mobile',
      base: Joi.string().regex(/^1[34578]\d{9}$/)
    });

    const result = Joi.validate("1230000000", Joi.mobile());

return:

{
    "error": {
        "isJoi": true,
        "name": "ValidationError",
        "details": [
            {
                "message": "\"value\" with value \"1230000000\" fails to match the required pattern: /^1[34578]\\d{9}$/",
                "path": [],
                "type": "string.regex.base",
                "context": {
                    "pattern": {},
                    "value": "1230000000",
                    "label": "value"
                }
            }
        ],
        "_object": "1230000000"
    },
    "value": "1230000000"
}
(3) 将错就错,直接拿 result.value 的值

不管怎样,result.value 的值做后续操作是一个好习惯。

七、与 sequelize 混用


待写……

本人试用了 joi-sequelize 库 [https://github.com/mibrito/joi-sequelize],发现有很多坑,这里不推荐了。考虑以后自己写一个吧。

joi-sequelize 的缺点:

1、库最近的提交是一年前了,一些 issue 也呈搁置状态

2、Bug [ 我已提交issue ]:使用时,model define 里的 DataTypes 会缺失很多类型值。例如我想定义一个 interest [兴趣爱好]的属性,写为DataTypes.ARRAY(DataTypes.STRING),却报错 TypeError: DataTypes.ARRAY is not a function

---下面这几点也不能怪他,毕竟数据库原生也没有提供这些定义---

3、依旧不能很好的表示 min(n)max(n), 尤其是 min(n)

4、依旧不能很好的不能表示“与其它字段的关系”

八、与 mongoose 混用


待写……

九、与前端混用


详见:joi-browser

https://github.com/jeffbski/joi-browser


参考资料:

[1]http://imweb.io/topic/572561798a0819f17b7d9d3e

[2]https://codeburst.io/joi-validate-input-and-define-databases-in-javascript-84adc6f1474b

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