Add validateMany feature method

[Twois]

Do you want to request a feature or report a bug?
Feature

What is the current behavior?
There is no way to run multiple validators on the shame field.

toySchema.path('name').validate(function(v) {
  if (v !== 'Turbo Man') {
    throw new Error('Need to get a Turbo Man for Christmas');
  }
  return true;
}, 'Name `{VALUE}` is not valid');

If the current behavior is a bug, please provide the steps to reproduce.

What is the expected behavior?
We should to be able to add multiple custom validators, and get back the result all of them.

I saw that there were some issue what reported the same, and the answer was, we can use mongoose-validator-all package. But that package have no more maintained for 1,5 years and anyway it should be supported by mongoose i think.

To prevent breaking changes, instead of overwrite the current validate system, just add a new one.

toySchema.path('password').validateMany([
function(v, f) {
  if (this.name == v) {    
   return {
        'passed': false,
         'message': `field [${f}] can be the same as name, value: [${v}]`
    };
  }
  return {
    'passed': true,
  };
},function(v, f) {
  if (this.confirmPw == v) {    //just for example
   return {
        'passed': false,
         'message': `field [${f}] have to be the same as password, confirmPw, password: [${this.confirmPw}, ${v}]`
    };
  }
  return {
    'passed': true,
  };
},
]);

Errors:

{
 "password": [{error Object}, {error Object}]
}

UI:
For be able to compare fields whit others e.g password, this should to contain the document itself as in pre hooks.

[vkarpov15]

I'm not sure I understand the problem here. You can multiple validate calls, schema.path().validate(validator1).validate(validator2) . Can you elaborate on your use case a bit?

[Twois]

We can add multiple validate, but as I know it will break at the first failure, and my suggestion is, to add a new validate method what run all validator function on the fields, even if some of them failed.

Update:

sometimes we want to test the min length and is the string contain specific character e.g, password. In that case, what a cool thing could be, if we can show to the user the two error in one step, Now the validate show only the first error.

[vkarpov15]

We will consider adding a similar feature for a future release. Until then, you can use something like Ramda's compose function