Allow Custom Validator to return Promise

I’ve been using this library with typescript. Then, I had found a semantic problem when I was trying to use Promises in the custom validators.

I have a custom validator to check if a username is already registered in the database. That’s why I need to implement the custom validation returning Promise.

I’m trying to do something like that:

router.use(validator({
  customValidators: {
    isUsernameTaken : (param, _id) => {
      return new Promise((resolve, reject) => {
        let conditions = {
          username: param
        };
        if (typeof _id !== 'undefined') {
          conditions['_id'] = {$ne: _id};
        }
        return UserService.findOne(conditions)
          .then(user => {
            if (user) {
              return reject(user);
            }
            return resolve(true);
          })
          .catch(err => {
            resolve(err)
        });
      });
    }
  }
}));

Thanks.

[kvcpr]

Why you don’t return true or false from UserService.findOne promise? I think it should work.

return UserService.findOne(conditions)
    .then(user => {
         if (user) {
            return false;
        }
        return true;
})

[dirkcuys]

@kacepe didn’t work for me - have a look at the code, it specifically checks if the promises were rejected or not.