Set polymorphic association in a manner that Rails picks up on the association add

[noahmatisoff]

I have a line in one of my models that looks like this:

has_many :notes, as: :notable, dependent: :destroy, after_add: :create_informal_note

I am sending a POST request to my Rails endpoint with JSON like this:

{
  "note": {
    "text": "Test note",
    "notable_id": 1,
    "notable_type": "AnotherModel"
  }
}

Rails & strong_parameters has no problem interpreting this and creating the data. However, due to the way the JSON request body is structured, Rails & strong_parameters simply just set the id and type fields.

This results in Rails not picking up on the added association, causing my after_add association callback not to trigger.