```ruby
require 'spec_helper'

describe ContributorsController do
  render_views

  describe 'GET index' do
    let!(:user)      { create(:user) }
    let!(:coach)     { create(:coach) }
    let!(:organizer) { create(:organizer) }

    it 'returns json representation of user with relevant roles' do
      get :index, format: :json
      expect(assigns(:contributors)).to eq [coach, organizer]
    end
  end
end
```

Sort lists for some added determinism
user
```ruby
require 'spec_helper'

describe ContributorsController do
  render_views

  describe 'GET index' do
    let!(:user)      { create(:user) }
    let!(:coach)     { create(:coach) }
    let!(:organizer) { create(:organizer) }

    it 'returns json representation of user with relevant roles' do
      get :index, format: :json
      expect(assigns(:contributors).sort).to eq [coach, organizer].sort
    end
  end
end
```
assistant