Joi Regex is not recognized as Regex Pattern

Question

I'm trying to make a validation rule for password field that it should consists of the following:

• Must have a number
• Must contain at least one upper-case
• Must contain at least one lower-case
• Must contain any of the following symbols [@$!]
• Should be at 8 to 20 characters only.

Here's the regex pattern I use: (?=.*[az])(?=.*[AZ])(?=.*\d)(?=.*[$@$.#?])[A-Za-z\d$@$.%*,&.]{8,20}

Tested on https://regexr.com/

Here's the Joi validation:

password: Joi.string()
.regex(
  '/(?=.*[a-z])(?=.*[A-Z])(?=.*d)(?=.*[$@$!#.])[A-Za-zd$@$!%*?&.]{8,20}/'
)
.required()
.min(8)
.max(20)

The error stacktrace:

{ AssertionError [ERR_ASSERTION]: pattern must be a RegExp
    at internals.String.regex (E:\nodeprojects\voting-system\voting-server\node_modules\joi\lib\types\string\index.js:120:14)
    at Object.<anonymous> (E:\nodeprojects\voting-system\voting-server\src\routes\user.js:16:6)
    at Module._compile (module.js:649:30)
    at Object.Module._extensions..js (module.js:660:10)
    at Module.load (module.js:561:32)
    at tryModuleLoad (module.js:501:12)
    at Function.Module._load (module.js:493:3)
    at Module.require (module.js:593:17)
    at require (internal/module.js:11:18)
    at files.map (E:\nodeprojects\voting-system\voting-server\node_modules\hapi-auto-route\lib\auto-route.js:21:27)
    at Array.map (<anonymous>)
    at Object.module.exports.getRoutes (E:\nodeprojects\voting-system\voting-server\node_modules\hapi-auto-route\lib\auto-route.js:19:18)
    at Object.register (E:\nodeprojects\voting-system\voting-server\node_modules\hapi-auto-route\index.js:16:32)
    at <anonymous>
  generatedMessage: false,
  name: 'AssertionError [ERR_ASSERTION]',
  code: 'ERR_ASSERTION',
  actual: false,
  expected: true,
  operator: '==' }

Answer 1

I know it has been about 2 years but I think coming late is better than never coming 🤣🤣.

You just have to put the pattern inside a RegExp()

This is how I edited your code :)

const pattern = "/(?=.*[a-z])(?=.*[A-Z])(?=.*d)(?=.*[$@$!#.])[A-Za-zd$@$!%*?&.]{8,20}/";

password: Joi.string()
.regex(RegExp(pattern)) // you have to put it in this way and it will work :)
.required()
.min(8)
.max(20)

I hope it helps you!

Answer 2

Regex doesn't need any single quote(Start/End) in the string

Here is an example that is working fine.

const joi = require("joi");

const strongPasswordRegex = /^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!@$%^&*-]).{8,}$/;
const stringPassswordError = new Error("Password must be strong. At least one upper case alphabet. At least one lower case alphabet. At least one digit. At least one special character. Minimum eight in length")

const schema = joi.object().keys({
    username: joi.string().required().min(4).max(15),
    password: joi.string().regex(strongPasswordRegex).error(stringPassswordError).required()
});

const notValid = schema.validate({ username: "MHamzaRajput", password: "Admin@admin123" }).error;

if (notValid) {
    console.log(notValid.message);
} else {
    console.log("payload validated successfully");
}