Allow to have optional remote relationships

[renato]

Is your proposal related to a problem?

When a remote relationship fails, the entire query fails with a response like:

{"errors":[{"extensions":{"path":"$","code":"unexpected"},"message":"Remote server response is not valid JSON: Failed reading: not a valid json value"}]}

Describe the solution you'd like

I'd like set a remote relationship as optional or with a "silent failure", so when I query it, the error response would be within the remote relationship node itself (I think it would require a breaking change to allow an error object in this node) or to just not return it at all. Eg.:

{
  product {
    id
    name
    shipping { <-- a remote relationship
      delivery_estimate
      shipping_cost
    }
  }
}

So if the remote relationship fails for some reason, I'd still get

{
  "product": {
    "id": 1,
    "name": "Some product",
    "shipping": null
  }
}

Describe alternatives you've considered

I need to show a page with all the remaining data and an error widget for the remote relationship. The only alternative I can see is doing two queries, one with the remote relationship only and another one with the remaining fields.

If the feature is approved, would you be willing to submit a PR?

Yes.