[BUGFIX beta] add assertions for reference methods on DS.Model

[pangratz]

Assertions are thrown when the specified relationship doesn't exist or
the passed type mismatches the one of the actual relationship.

---

This issue has been raised in the slack channel so adding assertions should help preventing this in the future.

[fivetanley]

is there a way to check for existence of a relationship without getting an exception?

[pangratz]

Yep:

let Person = this.store.modelFor("person");
let rels = Ember.get(Person, "relationshipsByName"); 
let personRel = rels.get("father");
if (personRel) {
  let { kind } = personRel;
  assert.ok(kind, "belongsTo");
}

[bmac]

👍