How to validate Enum String with Joi latest version?

Question

How do I validate Enum String?

I used to go with this as suggested from here: https://github.com/hapijs/joi/issues/1449

enum UserRole {
  Admin = 'admin',
  Staff = 'staff'
}

const validator = {
  create: Joi.object().keys({
    first_name: Joi.string().min(1),
    last_name: Joi.string()
      .min(1)
      .required(),
    password: Joi.string()
      .regex(/^[\x20-\x7E]+$/)
      .min(8)
      .max(72)
      .required(),
    role: Joi.string()
      .valid([UserRole.Admin, UserRole.Staff])
      .optional(),
    is_active: Joi.boolean().optional()
  })
};

But now , Error: Method no longer accepts array arguments: valid

Answer 1

I could make it work using Joi.any().valid() like this, hope works for you.

const Joi = require("@hapi/joi");

const roles = ["admin", "staff"];

const schema = Joi.object({
  first_name: Joi.string().min(1),
  last_name: Joi.string()
    .min(1)
    .required(),
  password: Joi.string()
    .regex(/^[\x20-\x7E]+$/)
    .min(8)
    .max(72)
    .required(),
  role: Joi.any().valid(...roles),
  is_active: Joi.boolean().optional()
});

Examples:

when a valid role is used no error.

const { error, value } = schema.validate({
  first_name: "Magnus",
  last_name: "Carlsen",
  password: "chess/1234",
  role: "staff"
});

console.log(error); //undefined

when no role is used no error.

const { error, value } = schema.validate({
  first_name: "Magnus",
  last_name: "Carlsen",
  password: "chess/1234"
});

console.log(error); //undefined

when a different role is used it gives validation error.

const { error, value } = schema.validate({
  first_name: "Magnus",
  last_name: "Carlsen",
  password: "chess/1234",
  role: "unknown"
});

console.log(error); // Error [ValidationError]: "role" must be one of [admin, staff]...

Answer 2

enum UserRole {
  Admin = 'admin',
  Staff = 'staff'
}

const validator = {
  create: Joi.object().keys({
    first_name: Joi.string().min(1),
    last_name: Joi.string()
      .min(1)
      .required(),
    password: Joi.string()
      .regex(/^[\x20-\x7E]+$/)
      .min(8)
      .max(72)
      .required(),
    role: Joi.string()
      .valid(UserRole.Admin, UserRole.Staff) // do not use an array
      .optional(),
    is_active: Joi.boolean().optional()
  })
};