Respect query constraints within relations when batchloading relationships

Describe the bug

I have a @hasOne relationship on one of my models, and I want to return this relationship in GraphQL, but the result is always null.

Expected behavior
I expect the selected_guide_booking field to return a model according to the @hasOne relationship.

In my other Laravel code (the blade files for example) this works perfectly. $booking->selected_guide_booking->price for example will return the right price. However when I do the same in a GraphQL query, it always returns null.

Schema

This is the relationship in my model:

public function selected_guide_booking()
    {
        return $this->hasOne('App\GuideBooking','booking_id')->where('guide_id', $this->guide_id);
    }

This is the field on my Booking Type:

selected_guide_booking: GuideBooking @hasOne

Each Booking can have multiple GuideBookings, but only has one GuideBooking where the guide_id is the same as the guide_id in the Booking.

Output/Logs

{
  "data": {
    "me": {
      "email": "test@test.com",
      "price": "35",
      "completed_incomingbookings": [
        {
          "selected_guide_booking": null,
          "review": {
            "id": "1",
            "text": "Bla bla bla bla",
            "ranking": "5",
            "tourist": {
              "realname": "Madeline Hayes MD",
              "photo": null,
              "about_tourist": "Adipisci magnam corrupti officia nulla. Sunt cupiditate nam consequatur sed omnis. Sit non voluptatem voluptatem autem. Repudiandae eum vero quia reiciendis qui nam. Quia ut ut quam. Alias reiciendis est vitae sint sint et."
            }
          }
        }
      ]
    }
  }
}

Environment

Lighthouse Version: 2.6.4
Laravel Version: 5.7.26
PHP Version: 7.2.11

Additional context

I've tried changing the @hasOne relationship on the selected_guide_booking field to a @hasMany relationship. This correctly returns the model, but it is inside an array. This breaks the other Laravel code, because it's expecting a hasOne relationship. A temporary fix could be to use a hasMany relationship and then putting [0] behind every returned model to retrieve the first model in the array, but this would make for some ugly code.

Start with the selected_guide_booking relationship on the Booking model and the selected_guide_booking field on the Booking Type. Reproduce the query using the hasOne relationship with its guide_id constraint, then compare it with the working review field and the hasMany workaround. Done means GraphQL returns the constrained GuideBooking model while the Laravel relationship remains hasOne.