Unclear error message when assigning wrong type to polymorphic relationship

[balinterdi]

I have the following relationships:

// app/models/business.js
import DS from 'ember-data';

const { attr, hasMany, belongsTo, Model } = DS;

export default Model.extend({
  logo:  belongsTo('image', { async: false }),
});

// app/models/image.js
import DS from 'ember-data';

const { Model, attr, belongsTo } = DS;

export default Model.extend({
  pictured:  belongsTo('pictured', { polymorphic: true })
});

When a logo.pictured relationship is set, I get the following error:

You cannot add a record of type 'business' to the 'image.pictured' relationship (only 'pictured' allowed)

I think this error might be made clearer as at the point it is thrown we know we're checking a polymorphic relationship so we might as well say:

"The business type does not implement pictured and thus cannot be assigned to the pictured relationship in image. Make it a descendant of pictured or use a mixin of the same name.

What do you think?

(Showed this to @pangratz at EmberFest a few days ago.)

[runspired]

@balinterdi I'd be all for this :)

[pete-the-pete]

@runspired and @balinterdi does this still need a contributor? If so, I'd like to pick it up.

[runspired]

@pete-the-pete it does!

[balinterdi]

@pete-the-pete Yes, feel free to snag it. Thank you!

[runspired]

Resolved by #5518