Improve support for isRequired on Relationships

[timleslie]

Due to the use of back-references, the isRequired flag is tricky to enforce for Relationship fields. At the moment I don't believe it's adequately implemented. This tasks needs someone to go through the Relationship field and ensure that the isRequired semantics are correctly implemented across all use cases.

[timleslie]

Also, we absolutely need some comprehensive testing around this (and uniqueness) in the same way we do for filter tests.

[stale]

It looks like there hasn't been any activity here in over 6 months. Sorry about that! We've flagged this issue for special attention. It wil be manually reviewed by maintainers, not automatically closed. If you have any additional information please leave us a comment. It really helps! Thank you for you contribution. :)

[jesstelford]

Just got stung by this:

keystone.createList('User', {
  fields: {
    name: { type: Text },
  },
});

keystone.createList('Post', {
  fields: {
    author: {
      type: Relationship,
      ref: 'User',
      isRequired: true,
    }
  }
});

The isRequired check appears to do nothing:

mutation createPost {
  createPost(data:{}) {
    id
    author {
      id
    }
  }
}

Successfully creates a new item.

---

I think the most basic implementation should at least:

1. Set the field as required in the graphQL schema. (currently it's just input PostCreateInput { author: UserRelateToOneInput }) Whoops, no, we can't do this because of our defaultValue() functions
2. Check for at least one of the possible operations (create / connect / disconnect / disconnectAll) having any value.

[MadeByMike]

We should update the docs until this is resolved.

[christopherliu]

Hello! It looks like isRequired is not supported on relationships in Keystone v6 as well as v5. Is this the proper channel to hear updates on this, given that the issue is closed, or should I open a new feature request issue?

[dcousens]

Hi @christopherliu,

There is an open discussion around this at #7310.
We'll try and answer with our reasoning for why isRequired is missing soon!