add warning regarding subscription and mutation redaction of relational fields

[chrisbonifacio]

Description of changes:

Add warning regarding subscription and mutation redaction of relational fields

Related GitHub issue #, if available:

aws-amplify/amplify-category-api#2636

aws-amplify/amplify-category-api#2609

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[PeteDuncanson]

Lovely to see this documented somewhere so others can be pointed to it. I wonder if we could add something to the graphql response too as a sign post to the reason the nested types are suddenly null? Was wondering if something could be done with the deprecated directive or similar, adds a message that devs can find ideally without throwing an exception but if you keep the expection at least there is a reason, link to these docs and a possible one liner explaining what has happened, a delicious DX rather than what we currently have.

Alternatively/Additionally add to the error messages explaining that the auth differs so whats why its coming back empty?

As it currently stands I went down rabbit holes trying to find what might have changed to cause it even to the dread of "have I over written live data with dev data somehow?" which is never a good feeling. An explaination (and link to these new docs) would have do wonders.

Thoughts?

[lawmicha]

Thanks for kicking this off, I reused the warning you have in this PR in the Relational Models page and added some extra details for the lazy/eager loading. I cherry-picked the commit over here so the warning can be updated in this PR as we iterate on it.

[pr0g]

I'm curious is there a plan to update the autogenerated code for mutations so relational fields are not included? This would be really handy as otherwise the autogenerated mutations will continue to throw errors such as:

"graphQLErrors": [
        {
            "path": [
                "createModelOfSomeKind",
                "linkedModel",
                "id"
            ],
            "locations": null,
            "message": "Cannot return null for non-nullable type: 'ID' within parent 'LinkedModel' (/createModelOfSomeKind/linkedModel/id)"
        },
        ...

Or is the recommentation to create custom mutations for everything from now on?

Thanks!

[sundersc]

@chrisbonifacio Could you please add info about the new feature flag graphqltransformer > subscriptionsInheritPrimaryAuth.

If enabled, subscriptions will inherit the primary model authorization rules for the relational fields.
If disabled, relational fields will be redacted in mutation response when there is a difference between auth rules between primary and related models.

Review inadvertently satisfied documentation team requirement