Source pointer format for relationship error?

I am using ember-data and marshmallow-jsonapi, respectively, for my frontend and backend. If a relationship has an error, marshmallow-jsonapi adds /data to the end of the pointer path. However, when ember-data serializes those errors, it appends ‘/data’ to the relationship attribute name, e.g. institution/data instead of institution.

So what is the correct format for the pointer of a relationship?

  1. “pointer”: “/data/relationships/institution/data”
  2. “pointer”: “/data/relationships/institution”

Hm, had I similar question I typed into google and ended up here. I could not find anything specific to errors on relationships, neihter here http://jsonapi.org/format/#error-objects nor there http://jsonapi.org/examples/#error-objects-source-usage

To me, it would also make sense to have something like

{
  "code":   "226",
  "source": { "relationship": "institution" },
  "title": "Institution missing"
}

I don’t know how ember data handles either error source pointer you presented. But arguably, one cannot know exactly how to construct errors for relationships from the jsonapi specification.

Extrapolating based on the example in the JSON API docs:

[e.g. “/data” for a
primary data object, or “/data/attributes/title” for a specific attribute].

It seems to me that if there is a problem with the relationship in general (e.g., it is not allowed), then the pointer should be to “the primary relationship object”, that is /data/relationships/institution/data.

Whereas if there is a problem with the id (it does not exist) then the pointer should be /data/relationships/institution/data/id.

To me this seems inline with the specification, and is coincidentally also the conclusion marshmallow-jsonapi came to.

In the end though, since it isn’t strongly specified, I’m not sure it matters so much, as long as the pointer is a valid JSON pointer and makes sense in the context of the error.