Conflict between options `debug`, `fallback` and `allowExternalErrors`

Bug report

• I have checked other issues to make sure this is not a duplicate.

Describe the bug

Hey @maticzav I have tests some config, and it’s seems there is some conflicts between debug, fallback and allowExternalErrors.

In my config, I just put allowExternalErrors to true (like in my previous settings in the v2) The bug is here: https://github.com/maticzav/graphql-shield/blob/eb333b85db36afff5729e37553985f213f8513e4/src/rules.ts#L69-L73

The problem is that the try/catch is managed here by the options.debug, why?

Example rule

const authRule = rule()(async (parent, args, ctx: Context) => {
  const user = ctx.user
  if (!user || !user.id) {
    throw new MyAwesomeAuthenticationError()
  }
  return true
})

shield({
  Query: {
    me: authRule
  }
}, {
  allowExternalErrors: true
}

Expected behavior

Receive a custom error like Not Authenticated or You're not allowed etc.

Actual behaviour

I always receive the default fallback error Not Authorised!.

[johannpinson]

Hey! As discussed together, I understand better the difference between “returning” and “rejecting” eventual errors between an rule and the middleware function. All is good for me, I close the issue 👍

[maticzav]

I think you should return a custom error if you want to provide additional information. I imagine fallback could be a function but can hardly see significant benefits in doing it.

I am still confused about the 3. topic. If I remember the tests correctly, there is no difference in returning an error and throwing it. Could you provide the expected and actual response so I can better understand what the nucleus of the issue is?