Add support for regex string for password policy validatorPattern setting

[bhaskaryasa]

fixes issue #3302

[acinader]

@bhaskaryasa this looks good to me. one question, if you supply a bad regex string like say: \xx

what happens? I'd think that you'd want the server to not start and make sure that you get a decent error message or stack trace so it is obvious what is causing the failure?

what do you think?

[livingstonef]

@bhaskaryasa This is good! Particularly thorny issue if you are using the parse-server lib directly (i.e $ parse-server /path-to-config.json). It is basically impossible to supply either a validation callback or pure regex. this fixes the regex bit. still don't think you can pass a callback in the currently documented way.

@acinader before this fix, if you submit a regex string it fails JSON validation with "unexpected token..."

[flovilmart]

@livingstonef you can provide a 'js' config file as well, as it's loaded through a require call :)

[bhaskaryasa]

@acinader - I believe JSON parsing itself would fail if you passed something like '\xx'. That should cause the Parse Server startup failure with the exception logged.

[bhaskaryasa]

@flovilmart - I did not know that was possible!! Nice 👍

[acinader]

@bhaskaryasa yeah, that'd be my guess to. Can you please verify that the server doesn't start and that the error doesn't get eaten somehow?

[bhaskaryasa]

@acinader - Yes, tested. Startup fails with SyntaxError: Unexpected token x in JSON at position 202.
I think we are good.

[dkarviga]

@flovilmart could you please provide an example of js file that can be used for initialization of parse-server?

[flovilmart]

// config.js
module.exports = {
  appId: "hello",
  masterKey: "world"
  /* more options */
}

$ parse-server ./config.js

[dkarviga]

@flovilmart thanks!