puyopuyotetr.is/spec/controllers/api/v1/favourites_controller_spec.rb

require 'rails_helper'

RSpec.describe Api::V1::FavouritesController, type: :controller do
  render_views

  let(:user)  { Fabricate(:user) }
  let(:token) { double acceptable?: true, resource_owner_id: user.id }

  before do
    Fabricate(:favourite, account: user.account)
    allow(controller).to receive(:doorkeeper_token) { token }
  end

  describe 'GET #index' do
    it 'returns http success' do
      get :index, params: { limit: 1 }

      expect(response).to have_http_status(:success)
    end
  end
end