Approaching App Controller load problem

eg_spec.rb

require 'spec_helper'
require_relative '../../../../apps/api/application'

RSpec.describe "Api::Controllers::Stuff::Create" do
  let(:action) { Api::Controllers::Stuff::Create.new }

  before(:all) do
    Api::Application.preload!
  end

  context "successfully performing the action" do
    it "causes stuff to happen" do
      thing = double()
      expect(Stuff).to receive(:new).with({a: 'b'}) { thing }
      expect(StuffRepository).to receive(:happen).with(thing)

      action.call(stuff: {a: 'b'})
    end
  end
end