How to write an exclusive regular expression?

Question

JavaScript

There is a chat with a list of reserved logins (bots). How to create a regular expression that will skip logins for registration that do not match the logins from the list? We need a regular expression so as not to fence another method for validation, but use the mongoose model.

login: {
    type: String,
    required: true,
    unique: true,
    validate: /[a-zA-Z\d_]{5,16}/          // <- вот тут нужно воткнуть регулярку
  }

UPD1: changed like this:

login: {
    type: String,
    required: true,
    unique: true,
    validate: {
      validator: function(v) {
        return /[a-zA-Z\d_]{5,16}/.test(v);
      },
      message: "Некорректный логин '{VALUE}'! Логин может содержать английские буквы, цифры и символ '_'. Допустимая длина логина от 5 до 16 символов."
      }
  }

But there is still no check for reserved logins. You can do an if in the validator, but then how do you change the message?

Answer 1

UPD: I'm sorry, the first edition of the answer is incorrect - I was too lazy to figure it out. Here is the code for your solution:

// Если просто регулярка, то:

var botLoginReg = /^(?!(login1|login2|login3)$)[a-z\d_]{5,16}$/i;

// Если есть массив с логинами (наверняка есть):

var botsLoginsArray = [
    'login1',
    'login2',
    'login3'
];

var botLoginReg = new RegExp(`^(?!(${botsLoginsArray.join('|')})$)[a-zA-Z\d_]{5,16}`, 'i');